Publications by year
In Press
Madden JR, Van Horik JO (In Press). A problem with problem solving: motivational traits, but not cognition, predict success on novel operant foraging tasks. Animal Behaviour
Van Horik JO, Langley EJG, Whiteside MA, Madden JR (In Press). A single factor explanation for associative learning performance on colour discrimination problems in Common Pheasants (Phasianus colchicus). Intelligence
Van Horik JO, Langley EJG, Whiteside MA, Laker PR, Madden JR (In Press). Intra-individual variation in performance on novel variants of similar tasks influences single factor explanations of general cognitive processes. Royal Society Open Science
Van Horik JO, Langley E, Whiteside M, Beardsworth C, Madden J (In Press). Pheasants learn five different binomial colour discriminations and retain these associations for at least 27 days. Animal Behaviour and Cognition
2023
Madden JR, Buckley R, Ratcliffe S (2023). Large-scale correlations between gamebird release and management and animal biodiversity metrics in lowland Great Britain.
Ecol Evol,
13(5).
Abstract:
Large-scale correlations between gamebird release and management and animal biodiversity metrics in lowland Great Britain.
The ecological effects on populations of non-game species driven by the annual release and management of tens of millions of gamebirds for recreational shooting are complex and relatively poorly understood. We investigated these effects at a national scale, considering multiple taxa simultaneously. We used records from the UK National Biodiversity Network Atlas to compare animal species and diversity metrics previously suggested to be affected by behaviors of the released birds, or because resources or habitats are influenced by game management or both processes. We contrasted records from 1 km grid squares where gamebirds were reported released in Great Britain, and control squares with similar land cover but where no releases were reported. There were more records overall reported from release grid squares (RGS) compared with controls (CGS), perhaps due to greater reporting effort or greater biological richness. We found fewer foxes in RGS and fewest in grid squares with largest releases, but more carrion crows in RGS. We found no consistent effects for buzzards, ravens, jays, or magpies. There were more rodents and gray squirrels reported from RGS but no differences for reptiles. There were more butterflies but fewer beetles reported from RGS but no consistent patterns for Orthoptera or ground beetles considered common gamebird prey. Farmland and woodland birds exhibited higher abundance, richness, and diversity in RGS when considering absolute records, but woodland bird abundance and richness were lower when correcting for the relative number of records. These nationwide results, despite crude data resolution, reveal diverse effects of gamebird release and management at a national scale and across trophic levels, increasing some non-game animal populations while decreasing others. This should alert practitioners, opponents, and legislators that a focus on single taxa effects, either positive or negative, may obscure the simultaneous changes in other taxa.
Abstract.
Author URL.
Heathcote RJP, Whiteside MA, Beardsworth CE, Van Horik JO, Laker PR, Toledo S, Orchan Y, Nathan R, Madden JR (2023). Spatial memory predicts home range size and predation risk in pheasants. Nature Ecology & Evolution, 7(3), 461-471.
Raymond S, Spencer M, Chadwick EA, Madden JR, Perkins SE (2023). The impact of the COVID-19 lockdowns on wildlife–vehicle collisions in the UK.
Journal of Animal Ecology,
92(6), 1244-1255.
Abstract:
The impact of the COVID-19 lockdowns on wildlife–vehicle collisions in the UK
Wildlife–vehicle collisions (WVCs) cause millions of vertebrate mortalities globally, threatening population viability and influencing wildlife behaviour and survival. Traffic volume and speed can influence wildlife mortality on roads, but roadkill risk is species specific and depends on ecological traits. The COVID-19 pandemic, and associated UK-wide lockdowns, offered a unique opportunity to investigate how reducing traffic volume alters WVC. These periods of reduced human mobility have been coined the ‘anthropause’. We used the anthropause to identify which ecological traits may render species vulnerable to WVC. We did this by comparing the relative change in WVC of species with differing traits before and during the anthropause. We used Generalised Additive Model predictions to assess which of the 19 species most frequently observed as WVC in the UK exhibited changes in road mortality during two lockdown periods, March–May 2020 and December 2020–March 2021, relative to the same time periods in previous years (2014–2019). Compositional data analysis was used to identify ecological traits associated with changes in the relative number of observations during lockdown periods compared to previous years. WVC were, across all species, 80% lower during the anthropause than predicted. Compositional data analysis revealed proportionally fewer reports of nocturnal mammals, urban visitors, mammals with greater brain mass and birds with a longer flight initiation distance. Species that have several of these traits, and correspondingly significantly lower than predicted WVC during lockdowns, included badgers Meles meles, foxes Vulpes vulpes, and pheasants, Phasianus colchicus; we posit they stand to benefit most from reduced traffic, and, of the species studied here, have highest mortality under ‘normal’ traffic levels. This study identifies traits and species that may have experienced a temporary reprieve during the anthropause, and highlights the impacts of traffic-induced mortality on species numbers and ultimately on trait frequency in a road-dominated landscape. By taking advantage of reductions in traffic offered by the anthropause, we can understand how vehicles influence wildlife survival and behaviour and may be exerting a selective force for certain species and traits.
Abstract.
2022
Raby CL, Cusick JA, Fürtbauer I, Graham KE, Habig B, Hauber ME, Madden JR, Strauss AVH, Fernández-Juricic E (2022). An inclusive venue to discuss behavioural biology research: the first global Animal Behaviour Twitter Conference. Animal Behaviour, 187, 191-207.
Nathan R, Monk CT, Arlinghaus R, Adam T, Alós J, Assaf M, Baktoft H, Beardsworth CE, Bertram MG, Bijleveld AI, et al (2022). Big-data approaches lead to an increased understanding of the ecology of animal movement.
Science,
375(6582).
Abstract:
Big-data approaches lead to an increased understanding of the ecology of animal movement.
Understanding animal movement is essential to elucidate how animals interact, survive, and thrive in a changing world. Recent technological advances in data collection and management have transformed our understanding of animal "movement ecology" (the integrated study of organismal movement), creating a big-data discipline that benefits from rapid, cost-effective generation of large amounts of data on movements of animals in the wild. These high-throughput wildlife tracking systems now allow more thorough investigation of variation among individuals and species across space and time, the nature of biological interactions, and behavioral responses to the environment. Movement ecology is rapidly expanding scientific frontiers through large interdisciplinary and collaborative frameworks, providing improved opportunities for conservation and insights into the movements of wild animals, and their causes and consequences.
Abstract.
Author URL.
Knoch S, Whiteside MA, Madden J, Rose P, Fawcett T (2022). Hot-headed peckers: thermographic changes during aggression among juvenile pheasants (Phasianus colchicus). Philosophical Transactions of the Royal Society B: Biological Sciences, 377, 20200442-20200442.
2021
Perrins C, Buchanan G, Croxall J, Gray B, Sale R, Cranbrook, Madden JR (2021). Book reviews. Ibis, 163(2), 737-744.
Pacheco XP, Madden JR (2021). Does the social network structure of wild animal populations differ from that of animals in captivity?.
Behav Processes,
190Abstract:
Does the social network structure of wild animal populations differ from that of animals in captivity?
The social behaviour of wild animals living in groups leads to social networks with structures that produce group-level effects and position individuals within them with differential consequences for an individual's fitness. Social dynamics in captivity can differ greatly from those in wild conspecifics given the different constraints on social organization in wild populations, e.g. group size, predation pressure, distribution of resources (food, mates), which are all regulated by human carers in captive populations. The social networks of animals in zoos is expected to differ from those of free-living conspecifics. While many studies have described the social networks of a wide diversity of wild and captive animals, none has directly compared the networks of multiple groups of a single species both in the wild and in captivity. Meerkats, Suricata suricatta, are an excellent species to compare the social networks of wild and captive groups. We replicated the methods of Madden et al. (2009, 2011), who studied eight groups in the wild, in fifteen captive groups. We tested how network structures and individual positions in grooming, foraging competition and dominance networks differed between wild and captive groups. Groups of wild and captive meerkats differed in various aspects of their social network structure. Differences in the network may be due to individuals occupying different network positions and the difference in the number and strength of their connections to other individuals. This distinct way of interacting and associating could be a result of group specific attributes, such as group size, and/or the attributes of the donor and recipient, including sex, status or age. Critically, the differences may be explained by the dissimilar living environment that each encounters.
Abstract.
Author URL.
Laker P (2021). FACTORS AFFECTING THE SOCIAL TRANSMISSION OF NOVEL BEHAVIOURS: FROM THE INDIVIDUAL TO THE GROUP.
Abstract:
FACTORS AFFECTING THE SOCIAL TRANSMISSION OF NOVEL BEHAVIOURS: FROM THE INDIVIDUAL TO THE GROUP
Social learning allows individuals to acquire beneficial information through observing or interacting with others. A consequence of social learning for group-living animals is that it can facilitate the spread of novel behaviours, individual-to-individual, across the group (social transmission). Following the development of sophisticated statistical techniques numerous studies have shown behaviours to spread via social transmission across numerous species. The speed and pattern of spread appears to be contingent on multiple factors including individual attributes of the model and the learner, the social structure and dynamics of the group and the physical environment that the group inhabits. However, the majority of these studies investigated behavioural spread across single, natural wild groups making it hard to disentangle the relative contributions of each factor. My thesis has taken an experimental, replicated approach to explore how factors of the individual, social environment and environmental conditions can affect social learning and transmission of behaviours. I do so in a way that independently manipulates one aspect of the physical or social environment whilst controlling for other additional factors. I used groups of both pheasant chicks (Phasianus colchicus) and domestic fowl chicks (Gallus gallus domesticus) to explore the effects of these factors on social learning and behavioural transmission. Firstly, I looked at factors of the individual - I found individuals to vary greatly in social learning performance on a novel foraging task but their sex, mass, dominance ranking and social position did not explain this individual variation (Chapter 2). I then explored factors of the social environment through manipulating group size (Chapter 3), group structure (Chapter 4) and social foraging dynamics (Chapter 6) to determine their effect on social transmission. Increasing group size during interaction with a novel foraging task did not result in faster behavioural spread as predicted and thus indicates that total numbers of connections to informed individuals may not always best describe the likelihood of social learning (Chapter 3). Similarly, increasing the modularity of a population’s network (how clustered it is) did not limit behavioural spread as expected or lead to the establishment of specific behavioural variants within clusters (Chapter 4). These two results indicate that social transmission may follow more complex rules that incorporate proportions of connections to informed individuals, social reinforcement and forgetting rates that influence social learning and transmission of behaviours. By manipulating the social environment, I found scrounging opportunity to greatly facilitate the spread of a novel foraging behaviour (Chapter 5). I reason that this is likely due to the particular social learning mechanism (local/stimulus enhancement) deployed to acquire the behaviour. Lastly, making the group’s environment less predictable did not (contrary to predictions) affect how individuals used social information in a separate context (Chapter 6), suggesting that reliance on social information is not generalised across contexts. Taken together this thesis challenges the assumptions and predictions of several current theoretical models about the use of and processes underlying social transmission of behaviours, and clearly reveals a number of factors that appear critical in shaping the use and outcomes of social learning.
Abstract.
Laker P (2021). FACTORS AFFECTING THE SOCIAL TRANSMISSION OF NOVEL BEHAVIOURS: FROM THE INDIVIDUAL TO THE GROUP.
Abstract:
FACTORS AFFECTING THE SOCIAL TRANSMISSION OF NOVEL BEHAVIOURS: FROM THE INDIVIDUAL TO THE GROUP
Social learning allows individuals to acquire beneficial information through observing or interacting with others. A consequence of social learning for group-living animals is that it can facilitate the spread of novel behaviours, individual-to-individual, across the group (social transmission). Following the development of sophisticated statistical techniques numerous studies have shown behaviours to spread via social transmission across numerous species. The speed and pattern of spread appears to be contingent on multiple factors including individual attributes of the model and the learner, the social structure and dynamics of the group and the physical environment that the group inhabits. However, the majority of these studies investigated behavioural spread across single, natural wild groups making it hard to disentangle the relative contributions of each factor. My thesis has taken an experimental, replicated approach to explore how factors of the individual, social environment and environmental conditions can affect social learning and transmission of behaviours. I do so in a way that independently manipulates one aspect of the physical or social environment whilst controlling for other additional factors. I used groups of both pheasant chicks (Phasianus colchicus) and domestic fowl chicks (Gallus gallus domesticus) to explore the effects of these factors on social learning and behavioural transmission. Firstly, I looked at factors of the individual - I found individuals to vary greatly in social learning performance on a novel foraging task but their sex, mass, dominance ranking and social position did not explain this individual variation (Chapter 2). I then explored factors of the social environment through manipulating group size (Chapter 3), group structure (Chapter 4) and social foraging dynamics (Chapter 6) to determine their effect on social transmission. Increasing group size during interaction with a novel foraging task did not result in faster behavioural spread as predicted and thus indicates that total numbers of connections to informed individuals may not always best describe the likelihood of social learning (Chapter 3). Similarly, increasing the modularity of a population’s network (how clustered it is) did not limit behavioural spread as expected or lead to the establishment of specific behavioural variants within clusters (Chapter 4). These two results indicate that social transmission may follow more complex rules that incorporate proportions of connections to informed individuals, social reinforcement and forgetting rates that influence social learning and transmission of behaviours. By manipulating the social environment, I found scrounging opportunity to greatly facilitate the spread of a novel foraging behaviour (Chapter 5). I reason that this is likely due to the particular social learning mechanism (local/stimulus enhancement) deployed to acquire the behaviour. Lastly, making the group’s environment less predictable did not (contrary to predictions) affect how individuals used social information in a separate context (Chapter 6), suggesting that reliance on social information is not generalised across contexts. Taken together this thesis challenges the assumptions and predictions of several current theoretical models about the use of and processes underlying social transmission of behaviours, and clearly reveals a number of factors that appear critical in shaping the use and outcomes of social learning.
Abstract.
Capstick LA, Madden JR (2021). Factors predicting susceptibility of songbirds to nest predation by corvids.
EUROPEAN JOURNAL OF WILDLIFE RESEARCH,
67(6).
Author URL.
Madden JR (2021). How many gamebirds are released in the UK each year?.
European Journal of Wildlife Research,
67(4).
Abstract:
How many gamebirds are released in the UK each year?
Large numbers of gamebirds (pheasants Phasianus colchicus, red-legged partridges Alectoris rufa and mallard Anus platyrhynchos) are released annually in the UK to support recreational shooting. It is important to know how many of these birds are being released because their release and management has ecological effects on the wildlife and habitats of the UK. There is little regulation governing their release, and consequently, an accurate figure for the numbers being released is unknown. I took 12 different approaches, totalling 4329 estimates of the numbers of birds being released annually, based on a series of datasets that described numbers of birds being held for breeding, rearing or release, being released, managed or shot on game shoots, being shot by individual guns or being recorded during breeding bird surveys. These 12 approaches produced estimates ranging from 14.7 to 106.1 million with a mean of 43.2 million (95% CI 29.0–57.3 million). This suggests that 31.5 million pheasants (range 29.8–33.7 million), 9.1 million red-legged partridges (range 5.6–12.5 million) and 2.6 million mallard (range 0.9–6.0 million) are released annually in the UK. These figures differ substantially from both official records of gamebirds and previous published estimates, and I discuss why such differences may occur. I set these figures in the context of the number and behaviour of shoots operating in the UK. Improved estimates of numbers of gamebird being released are critical if we are to better understand the ecological effects occurring in areas where they are released and managed.
Abstract.
Beardsworth CE, Whiteside MA, Laker PR, Nathan R, Orchan Y, Toledo S, van Horik JO, Madden JR (2021). Is habitat selection in the wild shaped by individual‐level cognitive biases in orientation strategy?.
Ecology Letters,
24(4), 751-760.
Abstract:
Is habitat selection in the wild shaped by individual‐level cognitive biases in orientation strategy?
AbstractCognitive biases for encoding spatial information (orientation strategies) in relation to self (egocentric) or landmarks (allocentric) differ between species or populations according to the habitats they occupy. Whether biases in orientation strategy determine early habitat selection or if individuals adapt their biases following experience is unknown. We determined orientation strategies of pheasants, Phasianus colchicus, using a dual‐strategy maze with an allocentric probe trial, before releasing them (n = 20) into a novel landscape, where we monitored their movement and habitat selection. In general, pheasants selected for woodland over non‐woodland habitat, but allocentric‐biased individuals exhibited weaker avoidance of non‐woodland habitat, where we expected allocentric navigation to be more effective. Sex did not influence selection but was associated with speed and directional persistence in non‐woodland habitat. Our results suggest that an individual's habitat selection is associated with inherent cognitive bias in early life, but it is not yet clear what advantages this may offer.
Abstract.
Raby CL, Madden JR (2021). Moving academic conferences online: Aids and barriers to delegate participation.
Ecology and Evolution,
11(8), 3646-3655.
Abstract:
Moving academic conferences online: Aids and barriers to delegate participation
In-person academic conferences are important to disseminate research and provide networking opportunities. Whether academics attend in-person conferences is based on the cost, accessibility, and safety of the event. Therefore, in-person conferences are less accessible to academics and stakeholders that are unable to overcome some of these factors, which then act as a barrier to equal and inclusive participation. Additionally, the carbon footprint of conference travel is increasingly becoming a factor in deciding on whether to attend a conference. Online conferences may provide opportunities to mitigate these challenges. Here, we illustrate how a learned society can move their conference online. Then, comparing data acquired from the virtual conference and previous in-person conferences, we explore the aids and barriers influencing the decision of delegates to attend the meetings. Ultimately, moving meetings online aids delegate participation by removing concerns about travel, cost, and carbon emissions, but there remains a barrier to participation as online meetings are perceived as less effective for networking and social opportunities.
Abstract.
Raby CL, Madden JR (2021). Moving academic conferences online: Understanding patterns of delegate engagement.
ECOLOGY AND EVOLUTION,
11(8), 3607-3615.
Author URL.
Beardsworth CE, Whiteside MA, Capstick LA, Laker PR, Langley EJG, Nathan R, Orchan Y, Toledo S, van Horik JO, Madden JR, et al (2021). Spatial cognitive ability is associated with transitory movement speed but not straightness during the early stages of exploration.
Royal Society Open Science,
8(3).
Abstract:
Spatial cognitive ability is associated with transitory movement speed but not straightness during the early stages of exploration
. Memories about the spatial environment, such as the locations of foraging patches, are expected to affect how individuals move around the landscape. However, individuals differ in the ability to remember spatial locations (spatial cognitive ability) and evidence is growing that these inter-individual differences influence a range of fitness proxies. Yet empirical evaluations directly linking inter-individual variation in spatial cognitive ability and the development and structure of movement paths are lacking. We assessed the performance of young pheasants (
. Phasianus colchicus
. ) on a spatial cognition task before releasing them into a novel, rural landscape and tracking their movements. We quantified changes in the straightness and speed of their transitory paths over one month. Birds with better performances on the task initially made slower transitory paths than poor performers but by the end of the month, there was no difference in speed. In general, birds increased the straightness of their path over time, indicating improved efficiency independent of speed, but this was not related to performance on the cognitive task. We suggest that initial slow movements may facilitate more detailed information gathering by better performers and indicates a potential link between an individual's spatial cognitive ability and their movement behaviour.
.
Abstract.
Hall A, Sage RA, Madden JR (2021). The effects of released pheasants on invertebrate populations in and around woodland release sites.
ECOLOGY AND EVOLUTION,
11(19), 13559-13569.
Author URL.
Laker PR, Hoppitt W, Weiss M, Madden JR (2021). The modularity of a social group does not affect the transmission speed of a novel, socially learned behaviour, or the formation of local variants.
Proc Biol Sci,
288(1947).
Abstract:
The modularity of a social group does not affect the transmission speed of a novel, socially learned behaviour, or the formation of local variants.
The structure of a group is critical in determining how a socially learnt behaviour will spread. Predictions from theoretical models indicate that specific parameters of social structure differentially influence social transmission. Modularity describes how the structure of a group or network is divided into distinct subgroups or clusters. Theoretical modelling indicates that the modularity of a network will predict the rate of behavioural spread within a group, with higher modularity slowing the rate of spread and facilitating the establishment of local behavioural variants which can prelude local cultures. Despite prolific modelling approaches, empirical tests via manipulations of group structure remain scarce. We experimentally manipulated the modularity of populations of domestic fowl chicks, Gallus gallus domesticus, to affect the transmission of a novel foraging behaviour. We compared the spread of behaviour in populations with networks of high or low modularity against control populations where social transmission was prevented. We found the foraging behaviour to spread socially between individuals when the social transmission was permitted; however, modularity did not increase the speed of behavioural spread nor lead to the initial establishments of shared behavioural variants. This result suggests that factors in the social transmission process additional to the network structure may influence behavioural spread.
Abstract.
Author URL.
2020
Langley EJG, van Horik JO, Whiteside MA, Beardsworth CE, Weiss MN, Madden JR (2020). Early-life learning ability predicts adult social structure, with potential implications for fitness outcomes in the wild.
J Anim Ecol,
89(6), 1340-1349.
Abstract:
Early-life learning ability predicts adult social structure, with potential implications for fitness outcomes in the wild.
Social environments influence important ecological processes and can determine how selection acts on traits. Cognitive abilities can shape these social environments and in turn, affect individuals' fitness. To understand how cognitive abilities evolve, we need to understand the complex interplay between an individual's cognitive abilities, the social environment that they inhabit and the fitness consequences of these relationships. We measured the associative learning ability of pheasant chicks, Phasianus colchicus, then released them into the wild where we quantified their social position by observing their associations at feeding stations and monitored the number of days survived. We observed disassortative mixing by learning performance at the population level, and poor learners had more associates than good learners. Learning was beneficial for survival when focal individuals had fewer than four associates, but survival probability across learning abilities equalized for individuals with more than four associates. While the mechanisms underlying these relationships remain to be determined, the patterns of association exhibited by pheasants at feeders can be predicted by individual variation in cognitive performances and we suspect these patterns are related to differences in information use. Critically, these resulting patterns of association have fitness consequences for individuals that cannot be explained directly by their cognitive ability, but which could mediate selection on cognition.
Abstract.
Author URL.
Beardsworth C (2020). Exploring the relationship between spatial cognitive ability and movement ecology.
Abstract:
Exploring the relationship between spatial cognitive ability and movement ecology
Spatial cognitive ability is hypothesised to be a key determinant of animal movement patterns. However, empirical demonstrations linking intra-individual variations in spatial cognitive ability with movement ecology are rare. I reared ~200 simultaneously hatched pheasant chicks per year over three years in standardised conditions without parents, controlling for the confounding effects of experience, maternal influences and age. I tested the chicks on spatial cognitive tasks from three weeks old to obtain measures of inherent, early-life spatial cognitive ability. Each year, I released birds when 10 weeks old into an open-topped enclosure in woodland. Birds dispersed from this enclosure after about one-month. Importantly, all birds were released into the same, novel area simultaneously, thus their experiences and opportunities were standardised. I remotely tracked pheasant movement through either RFID antenna placed under 43 supplementary feeders situated throughout our field site (2016) or by using a novel reverse-GPS tracking system (2017-2018). Spatial cognitive ability, determined through binary spatial discrimination (2016) or a Barnes maze (2017), was related to the diversity of foraging sites an individual used (Chapter 2: 2016). Those with better spatial cognitive ability used a more diverse range of artificial feeders than poor performing counterparts, perhaps to retain a buffer of alternative foraging sites where resource profitability was known. I found no relationship between the timing of daily foraging onset between birds of differing cognitive ability (Chapter 3; 2016), which I had hypothesised to be a consequence of birds developing efficient routes between refuges and feeders. After establishing a reverse GPS system on our field site (Chapter 4: 2017), I collected more detailed information about pheasant movement and found that birds with higher accuracy scores on the cognition tasks initially moved between foraging and resting sites more slowly than inaccurate birds in novel environments, perhaps to gather more detailed information. Accurate birds increased their speed over one month to match the same speed as inaccurate birds. All birds increased the straightness of their routes at a similar rate. Lastly, I found intraspecific differences in the orientation strategy that birds used to solve a dual strategy maze task (Chapter 5: 2018). These differences predicted habitat use after release: birds that utilised landmarks (allocentric strategies) showed less aversion to urban habitats (farm buildings/yards) than egocentric/mixed strategy birds, which is potentially due to the presence of large, stable landmarks within these habitats. In this thesis, I provide several empirical links between spatial cognitive ability and movement ecology across a range of ecological contexts. I suggest that very specific cognitive processes may govern particular movement behaviours and that there is not one overarching general spatial ability.
Abstract.
Langley EJG, Adams G, Beardsworth CE, Dawson DA, Laker PR, van Horik JO, Whiteside MA, Wilson AJ, Madden JR (2020). Heritability and correlations among learning and inhibitory control traits.
Behavioral Ecology,
31(3), 798-806.
Abstract:
Heritability and correlations among learning and inhibitory control traits
AbstractTo understand the evolution of cognitive abilities, we need to understand both how selection acts upon them and their genetic (co)variance structure. Recent work suggests that there are fitness consequences for free-living individuals with particular cognitive abilities. However, our current understanding of the heritability of these abilities is restricted to domesticated species subjected to artificial selection. We investigated genetic variance for, and genetic correlations among four cognitive abilities: inhibitory control, visual and spatial discrimination, and spatial ability, measured on >450 pheasants, Phasianus colchicus, over four generations. Pheasants were reared in captivity but bred from adults that lived in the wild and hence, were subject to selection on survival. Pheasant chicks are precocial and were reared without parents, enabling us to standardize environmental and parental care effects. We constructed a pedigree based on 15 microsatellite loci and implemented animal models to estimate heritability. We found moderate heritabilities for discrimination learning and inhibitory control (h2 = 0.17–0.23) but heritability for spatial ability was low (h2 = 0.09). Genetic correlations among-traits were largely positive but characterized by high uncertainty and were not statistically significant. Principle component analysis of the genetic correlation matrix estimate revealed a leading component that explained 69% of the variation, broadly in line with expectations under a general intelligence model of cognition. However, this pattern was not apparent in the phenotypic correlation structure which was more consistent with a modular view of animal cognition. Our findings highlight that the expression of cognitive traits is influenced by environmental factors which masks the underlying genetic structure.
Abstract.
Madden JR (2020). How many gamebirds are released in the UK each year?.
Hall A (2020). Improving sustainability and monitoring within the UK pheasant release system.
Abstract:
Improving sustainability and monitoring within the UK pheasant release system
Between 39-57 million pheasants (Phasianus colchicus) are reared and released into the UK each year to accommodate recreational shooting. When carried out well, the associated land management can be very positive for the environment. However, releases at high densities can cause significant detrimental impacts for the wildlife around release sites. To improve the environmental sustainability of the shooting industry, methods must be found to; reduce the numbers of birds released without adversely affecting the shooting industry, increase knowledge and understanding of the impacts of pheasant releases on wildlife, and ensure that methods of monitoring pheasant populations are robust and reliable.
I showed that two separate rearing enhancements can be combined within a commercial rearing system and lead to greater pheasant harvests while still releasing the same numbers, so future release sizes can be reduced while harvest rates are maintained. This was achieved by the provisioning of perching material and providing an improved diet during rearing that resulted in improved pheasant survival post-release, enabling more to contribute to the harvest. Enhanced pheasants were harvested at rates 16-17% higher than Control pheasants on shoots releasing 2000 pheasants but 6% lower on shoots releasing 601-2000 pheasants. When release date was considered and not release size, shoots that released prior to August 22nd shot proportionately more Enhanced birds while shoots that released after shot proportionally more Control. Enhanced Rearing was cost-effective, only increasing the average cost per pheasant by 2.6%. Enhanced pheasants also flew higher, had larger hearts, larger breast muscles, thicker tarsi, gained weight more slowly over time, and impact invertebrates and habitats in and around the release pen no more than traditionally reared pheasants. Higher flying pheasants were shot at higher rates early in the shooting season but lower rates by the end. The overall flight performance of the pheasant population as a whole does not change over the course of the shooting season.
Releasing pheasants can lower total invertebrate biomass, slug counts, and detritivore counts within the release pen by 4 weeks post-release when overall invertebrate abundance is high, but this effect is removed by 9 weeks post-release. Conversely, when overall invertebrate abundance is low, there is little effect of releasing pheasants on invertebrates within release pens 4 weeks post-release, but by 9 weeks post-release, pen interiors can have higher total invertebrate biomass, total invertebrate counts, slug counts, and beetle counts. Releasing pheasants at higher stocking densities in one year can, prior to releases in following years, reduce the invertebrate biomass within the release pen, reduced detritivore counts both inside and outside of the pen, and increase slug counts both inside and outside of the pen.
I created a correction factor that accounts for the deterioration rate of the Multi-Tag patagial wing tag which is widely used for marking gamebirds. This allows past and future datasets using this tag to increase the accuracy of their findings. Even with the correction factor, I recommend that Multi-Tags not be used for long-term (>1 year) studies. I improved the accuracy of aging pheasants using proximal primary feather features by 1.3% by adding feather mass as an additional variable to length and diameter. I also found that machine learning may be overall less effective at aging pheasants via the proximal primary method alone. Finally, I discussed the implications of my findings and how they could impact wildlife conservation, pheasant and shoot management, and monitoring gamebird populations. I also identified several areas for potential future study.
Abstract.
Whiteside MA, Bess MM, Frasnelli E, Beardsworth CE, Langley EJG, van Horik JO, Madden JR (2020). No evidence that footedness in pheasants influences cognitive performance in tasks assessing colour discrimination and spatial ability.
Learning and Behavior,
48(1), 84-95.
Abstract:
No evidence that footedness in pheasants influences cognitive performance in tasks assessing colour discrimination and spatial ability
The differential specialization of each side of the brain facilitates the parallel processing of information and has been documented in a wide range of animals. Animals that are more lateralized as indicated by consistent preferential limb use are commonly reported to exhibit superior cognitive ability as well as other behavioural advantages. We assayed the lateralization of 135 young pheasants (Phasianus colchicus), indicated by their footedness in a spontaneous stepping task, and related this measure to individual performance in either 3 assays of visual or spatial learning and memory. We found no evidence that pronounced footedness enhances cognitive ability in any of the tasks. We also found no evidence that an intermediate footedness relates to better cognitive performance. This lack of relationship is surprising because previous work revealed that pheasants have a slight population bias towards right footedness, and when released into the wild, individuals with higher degrees of footedness were more likely to die. One explanation for why extreme lateralization is constrained was that it led to poorer cognitive performance, or that optimal cognitive performance was associated with some intermediate level of lateralization. This stabilizing selection could explain the pattern of moderate lateralization that is seen in most non-human species that have been studied. However, we found no evidence in this study to support this explanation.
Abstract.
van Horik JO, Beardsworth CE, Laker PR, Whiteside MA, Madden JR (2020). Response learning confounds assays of inhibitory control on detour tasks.
Anim Cogn,
23(1), 215-225.
Abstract:
Response learning confounds assays of inhibitory control on detour tasks.
The ability to inhibit prepotent actions towards rewards that are made inaccessible by transparent barriers has been considered to reflect capacities for inhibitory control (IC). Typically, subjects initially reach directly, and incorrectly, for the reward. With experience, subjects may inhibit this action and instead detour around barriers to access the reward. However, assays of IC are often measured across multiple trials, with the location of the reward remaining constant. Consequently, other cognitive processes, such as response learning (acquisition of a motor routine), may confound accurate assays of IC. We measured baseline IC capacities in pheasant chicks, Phasianus colchicus, using a transparent cylinder task. Birds were then divided into two training treatments, where they learned to access a reward placed behind a transparent barrier, but experienced differential reinforcement of a particular motor response. In the stationary-barrier treatment, the location of the barrier remained constant across trials. We, therefore, reinforced a fixed motor response, such as always go left, which birds could learn to aid their performance. Conversely, we alternated the location of the barrier across trials for birds in the moving-barrier treatment and hence provided less reinforcement of their response learning. All birds then experienced a second presentation of the transparent cylinder task to assess whether differences in the training treatments influenced their subsequent capacities for IC. Birds in the stationary-barrier treatment showed a greater improvement in their subsequent IC performance after training compared to birds in the moving-barrier treatment. We, therefore, suggest that response learning aids IC performance on detour tasks. Consequently, non-target cognitive processes associated with different neural substrates appear to underlie performances on detour tasks, which may confound accurate assays of IC. Our findings question the construct validity of a commonly used paradigm that is widely considered to assess capacities for IC in humans and other animals.
Abstract.
Author URL.
Sage RB, Hoodless AN, Woodburn MIA, Draycott RAH, Madden JR, Sotherton NW (2020). Summary review and synthesis: effects on habitats and wildlife of the release and management of pheasants and red-legged partridges on UK lowland shoots.
WILDLIFE BIOLOGY,
2020(4).
Author URL.
Griffin KR, Beardsworth CE, Laker PR, van Horik JO, Whiteside MA, Madden JR (2020). The inhibitory control of pheasants (Phasianus colchicus) weakens when previously learned environmental information becomes unpredictable.
Animal Cognition,
23(1), 189-202.
Abstract:
The inhibitory control of pheasants (Phasianus colchicus) weakens when previously learned environmental information becomes unpredictable
Inhibitory control (IC) is the ability to intentionally restrain initial, ineffective responses to a stimulus and instead exhibit an alternative behaviour that is not pre-potent but which effectively attains a reward. Individuals (both humans and non-human animals) differ in their IC, perhaps as a result of the different environmental conditions they have experienced. We experimentally manipulated environmental predictability, specifically how reliable information linking a cue to a reward was, over a very short time period and tested how this affected an individual’s IC. We gave 119 pheasants (Phasianus colchicus) the opportunity to learn to associate a visual cue with a food reward in a binary choice task. We then perturbed this association for half the birds, whereas control birds continued to be rewarded when making the correct choice. We immediately measured all birds’ on a detour IC task and again 3 days later. Perturbed birds immediately performed worse than control birds, making more unrewarded pecks at the apparatus than control birds, although this effect was less for individuals that had more accurately learned the initial association. The effect of the perturbation was not seen 3 days later, suggesting that individual IC performance is highly plastic and susceptible to recent changes in environmental predictability. Specifically, individuals may perform poorly in activities requiring IC immediately after information in their environment is perturbed, with the perturbation inducing emotional arousal. Our finding that recent environmental changes can affect IC performance, depending on how well an animal has learned about that environment, means that interpreting individual differences in IC must account for both prior experience and relevant individual learning abilities.
Abstract.
Madden JR, Santilli F, Whiteside MA (2020). The welfare of game birds destined for release into the wild: a balance between early life care and preparation for future natural hazards.
Animal Welfare,
29(1), 1-18.
Abstract:
The welfare of game birds destined for release into the wild: a balance between early life care and preparation for future natural hazards
Globally, over 110 million game birds are reared annually and released for recreational hunting. Game birds differ from other reared livestock because they experience two very distinct environments during their lives. Chicks are first reared in captivity for 6-12 weeks under managed, stable conditions and then released into the wild. A limited set of 13 studies have explored how the rearing conditions experienced by chicks influences their pre-release welfare, typically in terms of physical injury (feather-pecking) or behavioural assays of stress responses. However, no studies have considered the specific indicators of welfare of game birds after release. We therefore need to draw from studies that do not specifically investigate welfare but instead ones that examine how rearing environments influence post-release morphology, behaviour and survival. Consequently, we reviewed how reared and wild-born game birds differ and suggest methods by which more naturalistic rearing conditions may be achieved. We noted five areas where artificial rearing deviates substantially from natural conditions: absence of adults; unnatural chick densities; unnatural diet; unnatural physical environment; and exclusion of predation risk. Mimicking or introducing some of these elements in game bird rearing practice could bring two benefits: i) facilitating more natural behaviour by the chicks during rearing; and ii) ensuring that birds after release are better able to cope with natural hazards. Together, these could result in an improved overall welfare for game birds. For example, enrichment of the spatial environment may serve to both improve welfare pre-release and after release into the wild. However, some adaptations may induce poor welfare for a short period in the young birds. For example, exposure to predators may be temporarily stressful, but ultimately such experiences in early life may permit them to better cope with such threats when released into the wild. Therefore, to achieve an optimal welfare for the entirety of a game bird's life, a careful balance between the conditions experienced in early life and adequate preparation for later life in the wild is required.
Abstract.
2019
Whiteside MA, van Horik JO, Langley EJG, Beardsworth CE, Capstick LA, Madden JR (2019). Patterns of association at feeder stations for Common Pheasants released into the wild: sexual segregation by space and time.
Ibis,
161(2), 325-336.
Abstract:
Patterns of association at feeder stations for Common Pheasants released into the wild: sexual segregation by space and time
Sexual segregation is common and can occur when sexes occupy different habitats, and/or when sexes aggregate assortatively within the same habitats. However, it is rarely studied in birds, with most previous work concentrating on differential settlement by the sexes in discrete habitats, often separated by large distances. Little attention has been paid to patterns of segregation within the same site. We reared 200 Common Pheasants Phasianus colchicus and released them onto a relatively small site of 250 ha and recorded their patterns of association and differential use of artificial feeders in space and time. Particular feeders were preferred by one sex, although we found no features of the local habitat which explained such preferences. Furthermore, we found sex differences in the use of feeders throughout the day, with females preferentially visiting them in the morning and the proportion of females visiting feeders increasing as the year progressed. Social network analyses found that in the first month after release into the wild, females did not associate strongly with other females, which was surprising as, prior to release, females have been shown to associate with other females in both semi-natural conditions and when tested in isolation. However, sexual segregation was clearly seen after 1 month of being released and became more pronounced as the year progressed. Females associated with other females from November to February, whereas males avoided other males over this same period. Sexes became less likely to associate with one another in 5 of the 6 months monitored. Such avoidance observed in males suggests that they start to form territories much sooner than previously thought. Pheasants exhibit clear patterns of fine-scale sexual segregation based on space and time, which was observed in their social preferences at feeding sites. Such detailed fine-scale segregation is rarely observed in birds.
Abstract.
Capstick LA, Sage RB, Madden JR (2019). Predation of artificial nests in UK farmland by magpies (Pica pica): interacting environmental, temporal, and social factors influence a nest's risk.
EUROPEAN JOURNAL OF WILDLIFE RESEARCH,
65(3).
Author URL.
van Horik JO, Beardsworth CE, Laker PR, Whiteside MA, Madden JR (2019). Response learning confounds assays of inhibitory control on detour tasks.
van Horik JO, Beardsworth CE, Laker PR, Langley EJG, Whiteside MA, Madden JR (2019). Unpredictable environments enhance inhibitory control in pheasants.
Anim Cogn,
22(6), 1105-1114.
Abstract:
Unpredictable environments enhance inhibitory control in pheasants.
The ability to control impulsive actions is an important executive function that is central to the self-regulation of behaviours and, in humans, can have important implications for mental and physical health. One key factor that promotes individual differences in inhibitory control (IC) is the predictability of environmental information experienced during development (i.e. reliability of resources and social trust). However, environmental predictability can also influence motivational and other cognitive abilities, which may therefore confound interpretations of the mechanisms underlying IC. We investigated the role of environmental predictability, food motivation and cognition on IC. We reared pheasant chicks, Phasianus colchicus, under standardised conditions, in which birds experienced environments that differed in their spatial predictability. We systematically manipulated spatial predictability during their first 8 weeks of life, by either moving partitions daily to random locations (unpredictable environment) or leaving them in fixed locations (predictable environment). We assessed motivation by presenting pheasants with two different foraging tasks that measured their dietary breadth and persistence to acquire inaccessible food rewards, as well as recording their latencies to acquire a freely available baseline worm positioned adjacent to each test apparatus, their body condition (mass/tarsus3) and sex. We assessed cognitive performance by presenting each bird with an 80-trial binary colour discrimination task. IC was assessed using a transparent detour apparatus, which required subjects to inhibit prepotent attempts to directly acquire a visible reward through the barrier and instead detour around a barrier. We found greater capacities for IC in pheasants that were reared in spatially unpredictable environments compared to those reared in predictable environments. While IC was unrelated to individual differences in cognitive performance on the colour discrimination task or motivational measures, we found that environmental predictability had differential effects on sex. Males reared in an unpredictable environment, and all females regardless of their rearing environment, were less persistent than males reared in a predictable environment. Our findings, therefore, suggest that an individual's developmental experience can influence their performance on IC tasks.
Abstract.
Author URL.
2018
van Horik JO, Langley EJG, Whiteside MA, Laker PR, Beardsworth CE, Madden JR (2018). Do detour tasks provide accurate assays of inhibitory control?.
Proc Biol Sci,
285(1875).
Abstract:
Do detour tasks provide accurate assays of inhibitory control?
Transparent Cylinder and Barrier tasks are used to purportedly assess inhibitory control in a variety of animals. However, we suspect that performances on these detour tasks are influenced by non-cognitive traits, which may result in inaccurate assays of inhibitory control. We therefore reared pheasants under standardized conditions and presented each bird with two sets of similar tasks commonly used to measure inhibitory control. We recorded the number of times subjects incorrectly attempted to access a reward through transparent barriers, and their latencies to solve each task. Such measures are commonly used to infer the differential expression of inhibitory control. We found little evidence that their performances were consistent across the two different Putative Inhibitory Control Tasks (PICTs). Improvements in performance across trials showed that pheasants learned the affordances of each specific task. Critically, prior experience of transparent tasks, either Barrier or Cylinder, also improved subsequent inhibitory control performance on a novel task, suggesting that they also learned the general properties of transparent obstacles. Individual measures of persistence, assayed in a third task, were positively related to their frequency of incorrect attempts to solve the transparent inhibitory control tasks. Neophobia, Sex and Body Condition had no influence on individual performance. Contrary to previous studies of primates, pheasants with poor performance on PICTs had a wider dietary breadth assayed using a free-choice task. Our results demonstrate that in systems or taxa where prior experience and differences in development cannot be accounted for, individual differences in performance on commonly used detour-dependent PICTS may reveal more about an individual's prior experience of transparent objects, or their motivation to acquire food, than providing a reliable measure of their inhibitory control.
Abstract.
Author URL.
Langley EJG, Van Horik JO, Whiteside MA, Madden JR (2018). Group social rank is associated with performance on a spatial learning task.
Royal Society Open Science,
5(2).
Abstract:
Group social rank is associated with performance on a spatial learning task
Dominant individuals differ from subordinates in their performances on cognitive tasks across a suite of taxa. Previous studies often only consider dyadic relationships, rather than the more ecologically relevant social hierarchies or networks, hence failing to account for how dyadic relationships may be adjusted within larger social groups. We used a novel statistical method: randomized Elo-ratings, to infer the social hierarchy of 18 male pheasants, Phasianus colchicus, while in a captive, mixed-sex group with a linear hierarchy. We assayed individual learning performance of these males on a binary spatial discrimination task to investigate whether inter-individual variation in performance is associated with group social rank. Task performance improved with increasing trial number and was positively related to social rank, with higher ranking males showing greater levels of success. Motivation to participate in the task was not related to social rank or task performance, thus indicating that these rank-related differences are not a consequence of differences in motivation to complete the task. Our results provide important information about how variation in cognitive performance relates to an individual’s social rank within a group. Whether the social environment causes differences in learning performance or instead, inherent differences in learning ability predetermine rank remains to be tested.
Abstract.
Langley EJG, van Horik JO, Whiteside MA, Madden JR (2018). Individuals in larger groups are more successful on spatial discrimination tasks.
Animal Behaviour,
142, 87-93.
Abstract:
Individuals in larger groups are more successful on spatial discrimination tasks
To understand how natural selection may act on cognitive processes, it is necessary to reliably determine interindividual variation in cognitive abilities. However, an individual's performance in a cognitive test may be influenced by the social environment. The social environment explains variation between species in cognitive performances, with species that live in larger groups purportedly demonstrating more advanced cognitive abilities. It also explains variation in cognitive performances within species, with larger groups more likely to solve novel problems than smaller groups. Surprisingly, an effect of group size on individual variation in cognitive performance has rarely been investigated and much of our knowledge stems from impaired performance of individuals reared in isolation. Using a within-subjects design we assayed individual learning performance of adult female pheasants, Phasianus colchicus, while housed in groups of three and five. Individuals experienced the group sizes in a different order, but were presented with two spatial discrimination tasks, each with a distinct cue set, in a fixed order. We found that across both tasks individuals housed in the large groups had higher levels of success than individuals housed in the small groups. Individuals had higher levels of success on their second than their first task, irrespective of group size. We suggest that the expression of individual learning performance is responsive to the current social environment but the mechanisms underpinning this relationship require further investigation. Our study demonstrates that it is important to account for an individual's social environment when attempting to characterize cognitive capacities. It also demonstrates the flexibility of an individual's cognitive performance depending on the social context.
Abstract.
van Horik JO, Langley EJG, Whiteside MA, Laker PR, Madden JR (2018). Intra-individual variation in performance on novel variants of similar tasks influences single factor explanations of general cognitive processes.
ROYAL SOCIETY OPEN SCIENCE,
5(7).
Author URL.
Whiteside MA, Bess MM, Frasnelli E, Beardsworth CE, Langley EJG, von Horik JO, Madden JR (2018). Low survival of strongly footed pheasants may explain constraints on lateralization.
SCIENTIFIC REPORTS,
8 Author URL.
Whiteside MA, Bess MM, Frasnelli E, Beardsworth CE, Langley EJG, van Horik JO, Madden JR (2018). Low survival of strongly footed pheasants may explain constraints on lateralization.
Sci Rep,
8(1).
Abstract:
Low survival of strongly footed pheasants may explain constraints on lateralization.
Brain lateralization is considered adaptive because it leads to behavioral biases and specializations that bring fitness benefits. Across species, strongly lateralized individuals perform better in specific behaviors likely to improve survival. What constrains continued exaggerated lateralization? We measured survival of pheasants, finding that individuals with stronger bias in their footedness had shorter life expectancies compared to individuals with weak biases. Consequently, weak, or no footedness provided the highest fitness benefits. If, as suggested, footedness is indicative of more general brain lateralization, this could explain why continued brain lateralization is constrained even though it may improve performance in specific behaviors.
Abstract.
Author URL.
Boogert NJ, Madden JR, Morand-Ferron J, Thornton A (2018). Measuring and understanding individual differences in cognition.
Philos Trans R Soc Lond B Biol Sci,
373(1756).
Abstract:
Measuring and understanding individual differences in cognition.
Individuals vary in their cognitive performance. While this variation forms the foundation of the study of human psychometrics, its broader importance is only recently being recognized. Explicitly acknowledging this individual variation found in both humans and non-human animals provides a novel opportunity to understand the mechanisms, development and evolution of cognition. The papers in this special issue highlight the growing emphasis on individual cognitive differences from fields as diverse as neurobiology, experimental psychology and evolutionary biology. Here, we synthesize this body of work. We consider the distinct challenges in quantifying individual differences in cognition and provide concrete methodological recommendations. In particular, future studies would benefit from using multiple task variants to ensure they target specific, clearly defined cognitive traits and from conducting repeated testing to assess individual consistency. We then consider how neural, genetic, developmental and behavioural factors may generate individual differences in cognition. Finally, we discuss the potential fitness consequences of individual cognitive variation and place these into an evolutionary framework with testable hypotheses. We intend for this special issue to stimulate researchers to position individual variation at the centre of the cognitive sciences.This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'.
Abstract.
Author URL.
Whiteside MA, Van Horik J, Langley E, Beardsworth C, Madden J (2018). Size dimorphism and sexual segregation in pheasants: tests of three competing hypotheses. PeerJ
Madden JR, Langley EJG, Whiteside MA, Beardsworth CE, van Horik JO (2018). The quick are the dead: pheasants that are slow to reverse a learned association survive for longer in the wild.
Philos Trans R Soc Lond B Biol Sci,
373(1756).
Abstract:
The quick are the dead: pheasants that are slow to reverse a learned association survive for longer in the wild.
Cognitive abilities probably evolve through natural selection if they provide individuals with fitness benefits. A growing number of studies demonstrate a positive relationship between performance in psychometric tasks and (proxy) measures of fitness. We assayed the performance of 154 common pheasant (Phasianus colchicus) chicks on tests of acquisition and reversal learning, using a different set of chicks and different set of cue types (spatial location and colour) in each of two years and then followed their fates after release into the wild. Across all birds, individuals that were slow to reverse previously learned associations were more likely to survive to four months old. For heavy birds, individuals that rapidly acquired an association had improved survival to four months, whereas for light birds, slow acquirers were more likely to be alive. Slow reversers also exhibited less exploratory behaviour in assays when five weeks old. Fast acquirers visited more artificial feeders after release. In contrast to most other studies, we showed that apparently 'poor' cognitive performance (slow reversal speed suggesting low behavioural flexibility) correlates with fitness benefits in at least some circumstances. This correlation suggests a novel mechanism by which continued exaggeration of cognitive abilities may be constrained.This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'.
Abstract.
Author URL.
Langley EJG, van Horik JO, Whiteside MA, Beardsworth CE, Madden JR (2018). The relationship between social rank and spatial learning in pheasants, Phasianus colchicus: cause or consequence?.
PeerJ,
6Abstract:
The relationship between social rank and spatial learning in pheasants, Phasianus colchicus: cause or consequence?
Individual differences in performances on cognitive tasks have been found to differ according to social rank across multiple species. However, it is not clear whether an individual's cognitive performance is flexible and the result of their current social rank, modulated by social interactions (social state dependent hypothesis), or if it is determined prior to the formation of the social hierarchy and indeed influences an individual's rank (prior attributes hypothesis). We separated these two hypotheses by measuring learning performance of male pheasants, Phasianus colchicus, on a spatial discrimination task as chicks and again as adults. We inferred adult male social rank from observing agonistic interactions while housed in captive multi-male multi-female groups. Learning performance of adult males was assayed after social rank had been standardised; by housing single males with two or four females. We predicted that if cognitive abilities determine social rank formation we would observe: consistency between chick and adult performances on the cognitive task and chick performance would predict adult social rank. We found that learning performances were consistent from chicks to adults for task accuracy, but not for speed of learning and chick learning performances were not related to adult social rank. Therefore, we could not support the prior attributes hypothesis of cognitive abilities aiding social rank formation. Instead, we found that individual differences in learning performances of adults were predicted by the number of females a male was housed with; males housed with four females had higher levels of learning performance than males housed with two females; and their most recent recording of captive social rank, even though learning performance was assayed while males were in a standardized, non-competitive environment. This does not support the hypothesis that direct social pressures are causing the inter-individual variation in learning performances that we observe. Instead, our results suggest that there may be carry-over effects of aggressive social interactions on learning performance. Consequently, whether early life spatial learning performances influence social rank is unclear but these performances are modulated by the current social environment and a male's most recent social rank.
Abstract.
Author URL.
Madden JR, Hall A, Whiteside MA (2018). Why do many pheasants released in the UK die, and how can we best reduce their natural mortality?.
EUROPEAN JOURNAL OF WILDLIFE RESEARCH,
64(4).
Author URL.
2017
Madden JR, Meier C, Raj Pant S, van Horik JA, Laker PR, Langley EJG, Whiteside MA, Verbruggen F (2017). A novel continuous inhibitory-control task: Variation in individual performance by young pheasants (Phasianus colchicus) - dataset.
Abstract:
A novel continuous inhibitory-control task: Variation in individual performance by young pheasants (Phasianus colchicus) - dataset
Dataset to accompany the paper in Animal Cognition
Abstract.
Meier C, Pant SR, van Horik JO, Laker PR, Langley EJG, Whiteside MA, Verbruggen F, Madden JR (2017). A novel continuous inhibitory-control task: variation in individual performance by young pheasants (Phasianus colchicus).
Animal Cognition,
20(6), 1035-1047.
Abstract:
A novel continuous inhibitory-control task: variation in individual performance by young pheasants (Phasianus colchicus)
Inhibitory control enables subjects to quickly react to unexpectedly changing external demands. We assessed the ability of young (8 weeks old) pheasants Phasianus colchicus to exert inhibitory control in a novel response-inhibition task that required subjects to adjust their movement in space in pursuit of a reward across changing target locations. The difference in latencies between trials in which the target location did and did not change, the distance travelled towards the initially indicated location after a change occurred, and the change-signal reaction time provided a consistent measure that could be indicative of a pheasant’s inhibitory control. Between individuals, there was a great variability in these measures; these differences were not correlated with motivation either to access the reward or participate in the test. However, individuals that were slower to reach rewards in trials when the target did not change exhibited evidence of stronger inhibitory control, as did males and small individuals. This novel test paradigm offers a potential assay of inhibitory control that utilises a natural feature of an animal’s behavioural repertoire, likely common to a wide range of species, specifically their ability to rapidly alter their trajectory when reward locations switch.
Abstract.
Valletta J, Torney C, Kings M, Thornton A, Madden J (2017). Applications of machine learning in animal behaviour studies. Animal Behaviour
Whiteside MA, van Horik JO, Langley EJG, Beardsworth CE, Laker PR, Madden JR (2017). Differences in social preference between the sexes during ontogeny drive segregation in a precocial species. Behavioral Ecology and Sociobiology, 71
van Horik JO, Langley EJG, Whiteside MA, Madden JR (2017). Differential participation in cognitive tests is driven by personality, sex, body condition and experience. Behavioural Processes, 134, 22-30.
Whiteside MA, van Horik JO, Langley EJG, Beardsworth CE, Laker PR, Madden JR (2017). Erratum to: Differences in social preference between the sexes during ontogeny drive segregation in a precocial species (Behavioral Ecology and Sociobiology, 10.1007/s00265-017-2332-2).
Behavioral Ecology and Sociobiology,
71(8).
Abstract:
Erratum to: Differences in social preference between the sexes during ontogeny drive segregation in a precocial species (Behavioral Ecology and Sociobiology, 10.1007/s00265-017-2332-2)
The name of Christine E. Beardsworth was incorrectly spelled in the original version of this article. The original article was corrected.
Abstract.
Madden JR (2017). Individual differences in cognitive performance as a consequence of natural selection, constraints and trade-offs.
Abstract:
Individual differences in cognitive performance as a consequence of natural selection, constraints and trade-offs
Abstract.
Madden JR, Perkins SE (2017). Why did the pheasant cross the road? Long-term road mortality patterns in relation to management changes.
Royal Society Open Science,
4(10).
Abstract:
Why did the pheasant cross the road? Long-term road mortality patterns in relation to management changes
Pheasants (Phasianus colchicus) are commonly killed on UK roads, presenting a threat to motorists and a loss to the game shooting industry. Pheasants may be inherently susceptible, or the recent increase in their artificial rearing and release may have exacerbated the situation, either through population increases or because artificial rearing has altered movement behaviour. We compared intra-annual patterns of roadkill reported in the UK from the 1960s (prior to the onset of mass release programmes) with that from the 2010s (when pheasant release was well established and widespread), considering roadkill sex and locations and accounting for changes in traffic levels. Pheasants in the UK are disproportionately likely to be reported killed on roads. However, this likelihood has not changed notably over the past 50 years. Instead, the timing of roadkill has changed. Pheasants in the 2010s are no longer susceptible during their breeding season, unlike in the 1960s, perhaps because relatively few breed successfully. Instead, roadkill first peaks in September-November as pheasants disperse from release pens, females first. Roadkill declines over winter, but when supplementary feeding ceases in February, we see a second peak in roadkill. Roadkill rates are higher in regions of the UK where there is little arable farming and hence natural food supplies are scarce.
Abstract.
2016
Madden JR (2016). Bird brain: an exploration of avian intelligence, By Nathan Emery. Lewes, U.K.: Ivy Press (2016). Pp.192. Price £20 hardback. Animal Behaviour, 120, 41-42.
Whiteside MA, Langley EJG, Madden JR (2016). Males and females differentially adjust vigilance levels as group size increases: effect on optimal group size.
Animal Behaviour,
118, 11-18.
Abstract:
Males and females differentially adjust vigilance levels as group size increases: effect on optimal group size
A strong motivation for one individual to aggregate with others is to reduce their vigilance because other group members provide coverage and warning of approaching predators. This collective vigilance means that a focal individual is usually less susceptible to predation than when alone. However, individuals differ in their vigilance levels depending on status and context. They may also differ in how they adjust their vigilance levels as group size changes. This flexibility in response means that the collective vigilance of a group, and hence its optimal size, is not intuitive. We demonstrate, in both natural and experimental systems, that male and female pheasants, Phasianus colchicus, in harems differentially adjusted their vigilance levels as harem size changed. Females became less vigilant as harems became larger, and benefited by increasing their foraging time. Conversely, males became more vigilant as harems became larger. We calculated the collective probability that a harem would detect a predator. Within natural harem sizes, a male and two females exhibited the highest probability of collective detection, with decreases as more females joined. This optimal harem size matched the average harem size observed at our study site. Females may join harems for benefits of collective vigilance. Despite both sexes having a shared interest in larger harems for mating benefits, optimal harem size is influenced by trade-offs in a nonsexual behaviour, vigilance. This results in males with relatively small harems, females associating with less preferred males and each male being surrounded by fewer females than he could mate with.
Abstract.
Whiteside MA, Sage R, Madden JR (2016). Multiple behavioural, morphological and cognitive developmental changes arise from a single alteration to early life spatial environment, resulting in fitness consequences for released pheasants.
Royal Society Open Science,
3(3).
Abstract:
Multiple behavioural, morphological and cognitive developmental changes arise from a single alteration to early life spatial environment, resulting in fitness consequences for released pheasants
© 2016 the Authors. Subtle variations in early rearing environment influence morphological, cognitive and behavioural processes that together impact on adult fitness. We manipulated habitat complexity experienced by young pheasants (Phasianus colchicus) in their first seven weeks, adding a third accessible dimension by placing elevated perches in their rearing pens mimicking natural variation in habitat complexity. This simple manipulation provoked an interrelated suite of morphological, cognitive and behavioural changes, culminating in decreased wild mortality of birds from complex habitats compared with controls. Three mechanisms contribute to this: Pheasants reared with perches had a morphology which could enable them to fly to the higher branches and cope with prolonged roosting. They had a higher propensity to roost off the ground at night in the wild. More generally, these birds had more accurate spatial memory. Consequently, birds were at a reduced risk of terrestrial predation. The fitness consequences of variation in early rearing on behavioural development are rarely studied in the wild but we show that this is necessary because the effects can be broad ranging and not simple, depending on a complex interplay of behavioural, cognitive and morphological elements, even when effects that the treatments provoke are relatively short term and plastic.
Abstract.
Taylor S, Madden J (2016). The Effect of Pet Remedy on the Behaviour of the Domestic Dog (Canis familiaris).
Animals (Basel),
6(11).
Abstract:
The Effect of Pet Remedy on the Behaviour of the Domestic Dog (Canis familiaris).
Stress-affected behaviour in companion animals can have an adverse effect on animal health and welfare and their relationships with humans. This stress can be addressed using chemical treatments, often in conjunction with behavioural therapies. Here, we investigated the efficacy of one commercial pharmacological intervention, Pet Remedy, advertised as a natural stress relief product for mammals. We aimed to see whether the product lowered stress-affected behaviour in dogs placed in a non-familiar environment. Behavioural responses of 28 dogs were video recorded using a double-blind, placebo-controlled, and counterbalanced repeated measures design. Dogs were exposed to both a placebo and Pet Remedy plug-in diffuser for 30 min with an intervening period of approximately 7 days between conditions. Multivariate regression analysis identified no significant differences in behaviour in either the Pet Remedy or placebo condition. In conclusion, in the current study, Pet Remedy did not reduce behavioural indicators indicative of a stress response. To determine the effects of Pet Remedy, future research using a larger sample size and controlling for breed would be beneficial.
Abstract.
Author URL.
2015
Whiteside MA, Sage R, Madden JR (2015). Diet complexity in early life affects survival in released pheasants by altering foraging efficiency, food choice, handling skills and gut morphology.
J Anim Ecol,
84(6), 1480-1489.
Abstract:
Diet complexity in early life affects survival in released pheasants by altering foraging efficiency, food choice, handling skills and gut morphology.
Behavioural and physiological deficiencies are major reasons why reintroduction programmes suffer from high mortality when captive animals are used. Mitigation of these deficiencies is essential for successful reintroduction programmes. Our study manipulated early developmental diet to better replicate foraging behaviour in the wild. Over 2 years, we hand-reared 1800 pheasants (Phasianus colchicus), from 1 day old, for 7 weeks under different dietary conditions. In year one, 900 pheasants were divided into three groups and reared with (i) commercial chick crumb, (ii) crumb plus 1% live mealworm or (iii) crumb plus 5% mixed seed and fruit. In year two, a further 900 pheasants were divided into two groups and reared with (i) commercial chick crumb or (ii) crumb plus a combination of 1% mealworm and 5% mixed seed and fruit. In both years, the commercial chick crumb acted as a control treatment, whilst those with live prey and mixed seeds and fruits mimicking a more naturalistic diet. After 7 weeks reared on these diets, pheasants were released into the wild. Postrelease survival was improved with exposure to more naturalistic diets prior to release. We identified four mechanisms to explain this. Pheasants reared with more naturalistic diets (i) foraged for less time and had a higher likelihood of performing vigilance behaviours, (ii) were quicker at handling live prey items, (iii) were less reliant on supplementary feed which could be withdrawn and (iv) developed different gut morphologies. These mechanisms allowed the pheasants to (i) reduce the risk of predation by reducing exposure time whilst foraging and allowing more time to be vigilant; (ii) be better at handling and discriminating natural food items and not be solely reliant on supplementary feed; and (iii) have a better gut system to cope with the natural forage after the cessation of supplementary feeding in the spring. Learning food discrimination, preference and handling skills by the provision of a more naturalistic diet is essential prior to the release of pheasants in a reintroduction programme. Subsequent diet, foraging behaviour, gut morphology and digestive capabilities all work together as one nutritional complex. Simple manipulations during early development can influence these characteristics to better prepare an individual for survival upon release.
Abstract.
Author URL.
2014
Gordon DS, Madden JR, Lea SEG (2014). Both loved and feared: third party punishers are viewed as formidable and likeable, but these reputational benefits may only be open to dominant individuals.
PLoS One,
9(10).
Abstract:
Both loved and feared: third party punishers are viewed as formidable and likeable, but these reputational benefits may only be open to dominant individuals.
Third party punishment can be evolutionarily stable if there is heterogeneity in the cost of punishment or if punishers receive a reputational benefit from their actions. A dominant position might allow some individuals to punish at a lower cost than others and by doing so access these reputational benefits. Three vignette-based studies measured participants' judgements of a third party punisher in comparison to those exhibiting other aggressive/dominant behaviours (Study 1), when there was variation in the success of punishment (Study 2), and variation in the status of the punisher and the type of punishment used (Study 3). Third party punishers were judged to be more likeable than (but equally dominant as) those who engaged in other types of dominant behaviour (Study 1), were judged to be equally likeable and dominant whether their intervention succeeded or failed (Study 2), and participants believed that only a dominant punisher could intervene successfully (regardless of whether punishment was violent or non-violent) and that subordinate punishers would face a higher risk of retaliation (Study 3). The results suggest that dominance can dramatically reduce the cost of punishment, and that while individuals can gain a great deal of reputational benefit from engaging in third party punishment, these benefits are only open to dominant individuals. Taking the status of punishers into account may therefore help explain the evolution of third party punishment.
Abstract.
Author URL.
Madden JR, Whiteside MA (2014). Selection on behavioural traits during 'unselective' harvesting means that shy pheasants better survive a hunting season.
Animal Behaviour,
87(C), 129-135.
Abstract:
Selection on behavioural traits during 'unselective' harvesting means that shy pheasants better survive a hunting season
Recreational hunting can disrupt the population structure or alter the morphology of target populations. More subtly, such hunting may alter the behaviour of individuals in the target population, especially if individuals are culled nonrandomly. We assayed the behavioural temperaments of a sample of hand-reared and released pheasants, Phasianus colchicus. We could place birds on a behavioural continuum between bold or fast and shy or slow. Individual differences could not be explained by sex or mass. Birds were released into the wild and we followed their fate over a single hunting season. Birds that survived the hunting season were shyer or slower as juveniles than the original population mean. Males that died of disease or predation were relatively bold or fast as juveniles, while females dying of disease or predation were relatively shy or slow. Males that were bold or fast as juveniles were shot early in the season compared to females. Unselective hunting can skew the expression of behaviours in released gamebirds. This skew may explain why released birds subsequently fail to reproduce or are especially likely to die of natural causes once the hunting season has finished, and hence why it is difficult to establish wild populations of these species through reintroduction to an area where shooting takes place.
Abstract.
Thornton A, Isden J, Madden JR (2014). Toward wild psychometrics: Linking individual cognitive differences to fitness.
Behavioral Ecology,
25(6), 1299-1301.
Abstract:
Toward wild psychometrics: Linking individual cognitive differences to fitness
Our understanding of the processes underlying animal cognition has improved dramatically in recent years, but we still know little about how cognitive traits evolve. Following Darwinian logic, to understand how selection acts on such traits we must determine whether they vary between individuals, influence fitness, and are heritable. A handful of recent studies have begun to explore the relationship between variation in individual cognitive performance and fitness under natural conditions. Such work holds great promise, but its success is contingent on accurate characterization and quantification of the cognitive differences between individuals. Existing research has typically adopted a "problem-solving" approach, assuming that individuals that complete novel tasks have greater cognitive prowess than those that do not. We argue that this approach is incapable of determining that individual differences are due to cognitive factors. We propose the adoption of psychologically grounded psychometric testing and discuss the criteria necessary to examine the fitness consequences of cognitive variation in the wild.
Abstract.
2013
Isden J, Panayi C, Dingle C, Madden J (2013). Performance in cognitive and problem-solving tasks in male spotted bowerbirds does not correlate with mating success. Animal Behaviour
Isden J, Panayi C, Dingle C, Madden J (2013). Performance in cognitive and problem-solving tasks in male spotted bowerbirds does not correlate with mating success.
Animal Behaviour,
86(4), 829-838.
Abstract:
Performance in cognitive and problem-solving tasks in male spotted bowerbirds does not correlate with mating success
Individuals exhibiting a high level of cognitive ability may also exhibit more elaborate traits and so gain higher levels of mating success. This suggests that selection may act on cognitive performance through mate choice. Studies investigating this relationship have tended to focus on single cognitive tasks, or tasks that are closely related to existing natural behaviours, and individuals are frequently tested in captive conditions. This can introduce test artefacts and may tell us more about selection on specific display behaviours that we imagine being particularly cognitively complex, rather than a general cognitive ability. We tested free-living male spotted bowerbirds, Ptilonorhynchus maculatus, that exhibit elaborate sexual displays which appear to be cognitively demanding. We describe a method for testing individuals in the wild, without the need for constraint or captivity. We looked for evidence of a general cognitive ability in males by assaying their performance in a series of novel tasks reflecting their natural bower-building behaviour (bower maintenance) or capturing more abstract measures of cognitive ability (colour and shape discrimination, reversal learning, spatial memory and motor skills). We related performance in these tasks to their mating success. An individual's performance in one task was a relatively poor predictor of performance in any other task. However, an individual's performance across tasks could be summarized by a principal component which explained a level of total variance above which has previously been accepted as evidence of a general cognitive ability. We found no relationships between an individual's overall performance, or performance in any single task, and mating success. Our results highlight the need for further investigation of whether selection on cognition in bowerbirds is exerted through mate choice. We offer this as an example of how classic cognitive tasks can be transferred to the wild, thus overcoming some limitations of captive cognitive testing. © 2013 the Association for the Study of Animal Behaviour.
Abstract.
Boyland NK, James R, Mlynski DT, Madden JR, Croft DP (2013). Spatial proximity loggers for recording animal social networks: Consequences of inter-logger variation in performance.
Behavioral Ecology and Sociobiology,
67(11), 1877-1890.
Abstract:
Spatial proximity loggers for recording animal social networks: Consequences of inter-logger variation in performance
Social network analysis has become an increasingly popular method to link individual behaviour to population level patterns (and vice versa). Technological advances of recent years, such as the development of spatial proximity loggers, have enhanced our abilities to record contact patterns between animals. However, loggers are often deployed without calibration which may lead to sampling biases and spurious results. In particular, loggers may differ in their performance (i.e. some loggers may over-sample and other loggers may under-sample social associations). However, the consequences of inter-logger variation in logging performance has not been thoroughly considered or quantified. In this study, proximity loggers made by Sirtrack Ltd. were fitted to 20 dairy cows over a 3-week period. Contact records resulting from field deployment demonstrated variability in logger performance when recording contact duration, which was highly consistent for each logger over time. Testing loggers under standardised conditions suggested that inter-logger variation observed in the field was due to a combination of intrinsic variation in devices, and environmental/behavioural effects. We demonstrate the potential consequences that inter-logger variation in logging performance can have for social network analysis; particularly how measures of connectivity can be biased by logging performance. Finally, we suggest some approaches to correct data generated by proximity loggers with imperfect performance, that should be used to improve the robustness of future analyses. © 2013 Springer-Verlag Berlin Heidelberg.
Abstract.
Boyland NK, James R, Mlynski DT, Madden JR, Croft DP (2013). Spatial proximity loggers for recording animal social networks: consequences of inter-logger variation in performance. Behavioral Ecology and Sociobiology, 1-14.
Madden JR, Whiteside MA (2013). Variation in female mate choice and mating success is affected by sex ratio experienced during early life. Animal Behaviour
Madden JR, Whiteside MA (2013). Variation in female mate choice and mating success is affected by sex ratio experienced during early life.
Animal Behaviour,
86(1), 139-142.
Abstract:
Variation in female mate choice and mating success is affected by sex ratio experienced during early life
Females vary in their mate choice and consequent fitness outcomes. Individual differences may be explained by conditions experienced early in life. We tested whether the sex ratio at which young pheasants, Phasianus colchicus, were reared affected their adult sexual behaviour. Females reared in equal sex ratios discriminated strongly between males of differing attractiveness in choice tests and had the lowest variance in mating success. Conversely, females reared in female-biased sex ratios showed little discrimination between males based on their attractiveness, and exhibited highly skewed mating success with the majority gaining no copulations, but a quarter each gaining more copulations than any other female in the study. Early life environmental determination of variation in female choice could explain the lack of uniformity in mate choice and hence maintain variation in male traits in the face of directional sexual selection. © 2013 the Association for the Study of Animal Behaviour.
Abstract.
2012
Allcorn RI, Hilton GM, Fenton C, Atkinson PW, Bowden CGR, Gray GAL, Hulme M, Madden J, Mackley EK, Oppel S, et al (2012). Demography and breeding ecology of the critically endangered Montserrat Oriole.
Condor,
114(1), 227-235.
Abstract:
Demography and breeding ecology of the critically endangered Montserrat Oriole
The Montserrat Oriole (Icterus oberi) is a critically endangered species, confined to a small range in the hill forests of the volcanic island of Montserrat in the eastern Caribbean. From 1998 to 2005 we studied its breeding biology and survival of adults, finding that the Montserrat Oriole has a smaller clutch, more extended parental care, and higher adult survival than do orioles nesting in the North Temperate Zone. Adults' probabilities of survival varied by year from 0.60 to 0.76 but were similar for both sexes. Average clutch size was 2.6 eggs (± 0.04 SE), and post-fledging parental care was 40 ± 5 days. We found nest success of 29% (n = 275 nests), and 87% of nest failures were due to predation by either introduced rats (Rattus sp.) or the native Pearly-eyed Thrasher (Margar ops fuscatus). Most pairs initiated several nesting attempts after both failed and successful first broods, leading to an overall annual productivity of 1.2 fledged chicks per pair. Despite being able to raise up to three broods per season, the Montserrat Oriole's annual productivity was lower than that of its temperate-zone congeners, and we recommend that conservation management focus on enhancing nesting success via rat control. © the Cooper Ornithological Society 2012.
Abstract.
Madden JR, Nielsen JF, Clutton-Brock TH (2012). Do networks of social interactions reflect patterns of kinship?.
CURRENT ZOOLOGY,
58(2), 319-328.
Author URL.
Madden JR, Dingle C, Isden J, Sparfeld J, Goldizen AW, Endler JA (2012). Male spotted bowerbirds propagate fruit for use in their sexual display.
Curr Biol,
22(8), R264-R265.
Author URL.
2011
Madden JR, Isden J, Dingle C (2011). Commentary on review by Boogert et al.: Some problems facing females. Behavioral Ecology, 22(3), 461-462.
Madden JR, Clutton-Brock TH (2011). Experimental peripheral administration of oxytocin elevates a suite of cooperative behaviours in a wild social mammal.
Proceedings of the Royal Society B: Biological Sciences,
278(1709), 1189-1194.
Abstract:
Experimental peripheral administration of oxytocin elevates a suite of cooperative behaviours in a wild social mammal
The evolution and expression of different forms of cooperative behaviour (e.g. feeding, guarding, sentinel duties, etc.) are usually studied independently, with few studies considering them as a single syndrome. However, studies investigating individuals' investment across a suite of different behaviours reveal that they are correlated, suggesting a single mechanism determining the evolution and expression of cooperative behaviours. A hormonal mechanism could achieve this, and one possibility is oxytocin (OT), which affects several prosocial or alloparental behaviours independently. We show, using a double-blind experiment, that peripheral administration of OT to social, free-living meerkats Suricata suricatta elevates a suite of cooperative behaviours. Treated individuals increase their contributions to communal, cooperative activities (digging, guarding, pup-feeding and associating with pups) and decrease initiation of aggressive interactions, compared with a saline control. This suggests that different forms of cooperative behaviour form a single syndrome with a common causal basis. If our peripherally administered OT acts in the same way as the naturally released hormone, then a general tendency to prosociality may be modulated by this hormonal system. Therefore, it may be difficult for an individual to decouple expression of cooperative behaviours that provide the practitioner with benefits from those that provide the recipient with benefits. It may also explain why social species typically exhibit a suite of cooperative behaviours, without having to invoke independent evolution of each. © 2010 the Royal Society.
Abstract.
Madden JR, Clutton-Brock TH (2011). Experimental peripheral administration of oxytocin elevates a suite of cooperative behaviours in a wild social mammal.
Proc Biol Sci,
278(1709), 1189-1194.
Abstract:
Experimental peripheral administration of oxytocin elevates a suite of cooperative behaviours in a wild social mammal.
The evolution and expression of different forms of cooperative behaviour (e.g. feeding, guarding, sentinel duties, etc.) are usually studied independently, with few studies considering them as a single syndrome. However, studies investigating individuals' investment across a suite of different behaviours reveal that they are correlated, suggesting a single mechanism determining the evolution and expression of cooperative behaviours. A hormonal mechanism could achieve this, and one possibility is oxytocin (OT), which affects several prosocial or alloparental behaviours independently. We show, using a double-blind experiment, that peripheral administration of OT to social, free-living meerkats Suricata suricatta elevates a suite of cooperative behaviours. Treated individuals increase their contributions to communal, cooperative activities (digging, guarding, pup-feeding and associating with pups) and decrease initiation of aggressive interactions, compared with a saline control. This suggests that different forms of cooperative behaviour form a single syndrome with a common causal basis. If our peripherally administered OT acts in the same way as the naturally released hormone, then a general tendency to prosociality may be modulated by this hormonal system. Therefore, it may be difficult for an individual to decouple expression of cooperative behaviours that provide the practitioner with benefits from those that provide the recipient with benefits. It may also explain why social species typically exhibit a suite of cooperative behaviours, without having to invoke independent evolution of each.
Abstract.
Author URL.
Croft DP, Madden J, Franks D, James R (2011). Hypothesis testing in animal social networks. Trends in Ecology and Evolution, 26, 502-507.
Drewe JA, Eames KTD, Madden JR, Pearce GP (2011). Integrating contact network structure into tuberculosis epidemiology in meerkats in South Africa: Implications for control.
Prev Vet Med,
101(1-2), 113-120.
Abstract:
Integrating contact network structure into tuberculosis epidemiology in meerkats in South Africa: Implications for control.
Empirical studies that integrate information on host contact patterns with infectious disease transmission over time are rare. The aims of this study were to determine the relative importance of intra-group social interactions in the transmission of tuberculosis (TB; Mycobacterium bovis infection) in a population of wild meerkats (Suricata suricatta) in South Africa, and to use this information to propose an evidence-based intervention strategy to manage this disease. Detailed behavioural observations of all members of eight meerkat groups (n=134 individuals) were made over 24 months from January 2006 to December 2007. Social network analysis of three types of interaction (aggression, foraging competitions and grooming) revealed social structure to be very stable over time. Clustering of interactions was positively correlated with group size for both aggression (r=0.73) and grooming interactions (r=0.71), suggesting that infections may spread locally within clusters of interacting individuals but be limited from infecting all members of large groups by an apparent threshold in connections between different clusters. Repeated biological sampling every three months of all members of one social group (n=37 meerkats) was undertaken to quantify individual changes in M. bovis infection status. These empirical data were used to construct a dynamic network model of TB transmission within a meerkat group. The results indicated that grooming (both giving and receiving) was more likely than aggression to be correlated with M. bovis transmission and that groomers were at higher risk of infection than groomees. Intervention strategies for managing TB in meerkats that focus on those individuals engaging in the highest amount of grooming are therefore proposed.
Abstract.
Author URL.
Madden JR, Drewe JA, Pearce GP, Clutton-Brock TH (2011). The social network structure of a wild meerkat population: 3. Position of individuals within networks.
Behavioral Ecology and Sociobiology,
65(10), 1857-1871.
Abstract:
The social network structure of a wild meerkat population: 3. Position of individuals within networks
Individuals in social groups interact with numerous other group members in a polyadic network. Interactions can depend on the individual's own attributes (age, sex, status etc.), on their partner's attributes, and the group's network of social interactions. Previous studies tend to look at a subset of dyadic interactions, focusing on particular classes of individuals. We used social network analysis to explore how an individual wild meerkat's (Suricata suricatta) attributes related to their positions in three different interaction networks (grooming, dominance interactions, and foraging competitions) across eight groups. We asked whether individuals within groups associated assortatively and whether individuals with similar attributes occupied similar network positions. Differences in an individual's attributes did not consistently influence association patterns across different interaction network types. However, within network types, some attributes were especially influential across all groups. Grooming networks revealed negative assortativity by age and mass. Dominance networks revealed dominant-subordinate associations and high assortativity between males. Dominant individuals exhibited higher levels of dominance interactions and were aggressive to more different individuals than subordinates. Heavier individuals received higher levels of dominance interactions. Foraging competition networks revealed that younger and lighter individuals received higher overall levels of competitions and from more group members. Our observations were similar to focused studies on dyadic interactions but also revealed subtle differences. Future descriptions of social interactions should account for networks of social interactions occurring within a group and should be cautious about treating individuals with similar attributes as functionally similar with respect to their position within a social network. © 2011 Springer-Verlag.
Abstract.
2009
Madden JR, Kunc HP, English S, Manser MB, Clutton-Brock TH (2009). Calling in the gap: Competition or cooperation in littermates' begging behaviour?.
Proceedings of the Royal Society B: Biological Sciences,
276(1660), 1255-1262.
Abstract:
Calling in the gap: Competition or cooperation in littermates' begging behaviour?
Offspring are frequently raised alongside their siblings and are provisioned early in life by adults. Adult provisioning is stimulated by offspring begging, but it is unclear how each offspring should beg, given the begging behaviour of their siblings. It has previously been suggested that siblings may compete directly through begging for a fixed level of provisioning, or that siblings may cooperate in their begging in order to jointly elevate the level of provisioning by adults. We studied the begging behaviour of meerkat Suricata suricatta pups, explored how it changed as the begging behaviour of their littermates altered, and asked how the adults responded to group-level changes in begging.We found conflicting evidence for classic models of competitive and cooperative begging. Pups reared in larger litters begged at higher rates, yet experimentally increasing begging levels within groups caused individual begging rates to decrease. Pups decreased begging rates when close to other begging pups, and pups spaced further apart were fed more. Adults increased their overall level of provisioning as group levels of begging increased, but per capita provisioning decreased. Adults preferred to provision speakers playing back recordings of two pups begging alternately to recordings of the same two pups begging simultaneously. Therefore, we suggest that meerkat pups avoid some of the costs of direct competition imposed by an escalation of begging as other pups beg, by begging in gaps between the bouts of others or avoiding littermates. Such behaviour is also preferred by provisioning adults, thus providing additional benefits to the pups. © 2009 the Royal Society.
Abstract.
Madden JR, Kunc HP, English S, Manser MB, Clutton-Brock TH (2009). Calling in the gap: competition or cooperation in littermates' begging behaviour?.
Proc Biol Sci,
276(1660), 1255-1262.
Abstract:
Calling in the gap: competition or cooperation in littermates' begging behaviour?
Offspring are frequently raised alongside their siblings and are provisioned early in life by adults. Adult provisioning is stimulated by offspring begging, but it is unclear how each offspring should beg, given the begging behaviour of their siblings. It has previously been suggested that siblings may compete directly through begging for a fixed level of provisioning, or that siblings may cooperate in their begging in order to jointly elevate the level of provisioning by adults. We studied the begging behaviour of meerkat Suricata suricatta pups, explored how it changed as the begging behaviour of their littermates altered, and asked how the adults responded to group-level changes in begging. We found conflicting evidence for classic models of competitive and cooperative begging. Pups reared in larger litters begged at higher rates, yet experimentally increasing begging levels within groups caused individual begging rates to decrease. Pups decreased begging rates when close to other begging pups, and pups spaced further apart were fed more. Adults increased their overall level of provisioning as group levels of begging increased, but per capita provisioning decreased. Adults preferred to provision speakers playing back recordings of two pups begging alternately to recordings of the same two pups begging simultaneously. Therefore, we suggest that meerkat pups avoid some of the costs of direct competition imposed by an escalation of begging as other pups beg, by begging in gaps between the bouts of others or avoiding littermates. Such behaviour is also preferred by provisioning adults, thus providing additional benefits to the pups.
Abstract.
Author URL.
Madden JR, Kunc HJP, English S, Manser MB, Clutton-Brock TH (2009). Do meerkat (Suricata suricatta) pups exhibit strategic begging behaviour and so exploit adults that feed at relatively high rates?.
Behavioral Ecology and Sociobiology,
63(9), 1259-1268.
Abstract:
Do meerkat (Suricata suricatta) pups exhibit strategic begging behaviour and so exploit adults that feed at relatively high rates?
Adults vary in their generosity in provisioning the young and their sensitivity to the need of the young. Do the young modulate their behaviour so as to specifically target more high-provisioning adults? This is especially likely in situations with mobile, nutritionally dependent young. We studied cooperatively breeding meerkats Suricata suricatta, in which pups beg to parents and other adults in the group. We found that the young begged differently when next to different adults and that they are consistent in how they beg when next to each adult. Pups next to adults that provision at high rates beg at higher rates and spend longer with them, and these adults are generally more sensitive to increases in begging rate. Such behaviour has adaptive benefits to offspring in terms of increased likelihood of being fed. However, offspring do not appear to be actively seeking out high-provisioning adults or increasing their begging behaviour when they encounter one. Pups did not appear to actively discriminate between adults in their association or begging behaviour. We suggest instead that the relationship between an adult's relative contribution to pup feeding and the behaviour of its accompanying pup is driven by adult behaviour, with responsive adults that feed pups at a relatively higher rate preferentially associating with fast-begging hungry pups. © 2009 Springer-Verlag.
Abstract.
Madden JR, Clutton-Brock TH (2009). Manipulating grooming by decreasing ectoparasite load causes unpredicted changes in antagonism.
Proceedings of the Royal Society B: Biological Sciences,
276(1660), 1263-1268.
Abstract:
Manipulating grooming by decreasing ectoparasite load causes unpredicted changes in antagonism
It is thought that allogrooming is practised strategically in order to establish, maintain and reinforce social bonds between group members, exchanging one altruistic behaviour for a different form of reciprocated benefit at a later date. Correlational evidence supports this, but evidence of causality is lacking.We reduced parasite loads in eight meerkat Suricata suricatta groups, generating a substantial decrease in grooming. Contrary to the predictions, overall antagonism did not increase. However, within group networks, grooming increased towards individuals who increased their antagonism. This was restricted to antagonism focused on social position, rather than access to physical resources. The treatment also increased an alternative placatory behaviour: unprompted submissions. Following treatment, individuals performed higher rates of guarding and marking behaviours, suggesting that they were stressed. A reduction in opportunity to mediate stress through grooming may explain local rises in antagonism and corresponding increases in placatory behaviours. We suggest that meerkats use allogrooming (and submissions) as a facultative response to antagonism, rather than a pre-emptive strategy to avert it by establishing a network of associations, as has been suggested for primates. © 2009 the Royal Society.
Abstract.
Madden JR, Clutton-Brock TH (2009). Manipulating grooming by decreasing ectoparasite load causes unpredicted changes in antagonism.
Proc Biol Sci,
276(1660), 1263-1268.
Abstract:
Manipulating grooming by decreasing ectoparasite load causes unpredicted changes in antagonism.
It is thought that allogrooming is practised strategically in order to establish, maintain and reinforce social bonds between group members, exchanging one altruistic behaviour for a different form of reciprocated benefit at a later date. Correlational evidence supports this, but evidence of causality is lacking. We reduced parasite loads in eight meerkat Suricata suricatta groups, generating a substantial decrease in grooming. Contrary to the predictions, overall antagonism did not increase. However, within group networks, grooming increased towards individuals who increased their antagonism. This was restricted to antagonism focused on social position, rather than access to physical resources. The treatment also increased an alternative placatory behaviour: unprompted submissions. Following treatment, individuals performed higher rates of guarding and marking behaviours, suggesting that they were stressed. A reduction in opportunity to mediate stress through grooming may explain local rises in antagonism and corresponding increases in placatory behaviours. We suggest that meerkats use allogrooming (and submissions) as a facultative response to antagonism, rather than a pre-emptive strategy to avert it by establishing a network of associations, as has been suggested for primates.
Abstract.
Drewe JA, Madden JR, Pearce GP (2009). The social network structure of a wild meerkat population: 1. Inter-group interactions.
Behavioral Ecology and Sociobiology,
63(9), 1295-1306.
Abstract:
The social network structure of a wild meerkat population: 1. Inter-group interactions
Groups of individuals frequently interact with each other, but typically analysis of such interactions is restricted to isolated dyads. Social network analysis (SNA) provides a method of analysing polyadic interactions and is used to analyse interactions between individuals. We use a population of 12 groups (ca. 250 animals) of wild meerkats (Suricata suricatta) to test whether SNA can also be used to describe and elucidate patterns of inter-group interactions. Using data collected over 24 months, we constructed two sets of networks, based on direct encounters between groups and instances of roving males visiting other groups. We analysed replicated networks of each type of interaction to investigate similarities between networks of different social interactions as well as testing their stability over time. The two network types were similar to each other when derived from long-term data, but showed significant differences in structure over shorter timescales where they varied according to seasonal and ecological conditions. Networks for both types of inter-group interaction constructed from data collected over 3 months reliably described long-term (12- and 24-month) patterns of interactions between groups, indicating a stable social structure despite variation in group sizes and sex ratios over time. The centrality of each meerkat group in roving interactions networks was unaffected by the sex ratio of its members, indicating that male meerkats preferentially visit geographically close groups rather than those containing most females. Indeed, the strongest predictors of network structure were spatial factors, suggesting that, in contrast to analyses of intra-group interactions, analyses of inter-group interactions using SNA must take spatial factors into account. © 2009 Springer-Verlag.
Abstract.
Madden JR, Drewe JA, Pearce GP, Clutton-Brock TH (2009). The social network structure of a wild meerkat population: 2. Intragroup interactions.
Behavioral Ecology and Sociobiology,
64(1), 81-95.
Abstract:
The social network structure of a wild meerkat population: 2. Intragroup interactions
Knowledge of the structure of networks of social interactions is important for understanding the evolution of cooperation, transmission of disease, and patterns of social learning, yet little is known of how environmental, ecological, or behavioural factors relate to such structures within groups. We observed grooming, dominance, and foraging competition interactions in eight groups of wild meerkats (Suricata suricatta) and constructed interaction networks for each behaviour. We investigated relationships between networks for different social interactions and explored how group attributes (size and sex ratio), individual attributes (tenure of dominants), and ecological factors (ectoparasite load) are related to variation in network structure. Network structures varied within a group according to interaction type. Further, network structure varied predictably with group attributes, individual attributes, and ecological factors. Networks became less dense as group size increased suggesting that individuals were limited in their number of partners. Groups with more established dominant females were more egalitarian in their grooming and foraging competition interactions, but more despotic in their dominance interactions. The distribution of individuals receiving grooming became more skewed at higher parasite loads, but more equitable at low parasite loads. We conclude that the pattern of interactions between members of meerkat groups is not consistent between groups but instead depends on general attributes of the group, the influence of specific individuals within the group, and ecological factors acting on group members. We suggest that the variation observed in interaction patterns between members of meerkat groups may have fitness consequences both for individual group members and the group itself. © Springer-Verlag 2009.
Abstract.
Madden JR, Kunc HJP, English S, Clutton-Brock TH (2009). Why do meerkat pups stop begging?.
Animal Behaviour,
78(1), 85-89.
Abstract:
Why do meerkat pups stop begging?
Begging by young provokes adults to provide food for them. However, eventually begging by young and provisioning by adults cease and young become nutritionally independent. Why do young cease begging and so forgo food brought to them by adults? Three explanations have been proposed: (1) adults may not respond to begging anymore and cease feeding begging young; (2) young may voluntarily switch from begging to independent foraging as they gain more rewards from this; (3) young may become unable to produce stimulating begging calls. We tested these three explanations using meerkat, Suricata suricatta, pups. Playback of begging calls at groups where begging had naturally ceased provoked adults to resume provisioning, suggesting that adults had not stopped responding to begging. Experimental provision of food to pups mimicking either natural pup feeding or foraging success produced no differences in subsequent changes in begging or foraging behaviour, suggesting that pups were not assessing the most rewarding means of obtaining food and switching from begging to foraging accordingly. The begging calls of pups (aged 40-60 days) were acoustically different to those produced when they were juveniles (aged 100-120 days), and adults discriminated between rate-controlled playbacks of the two age classes of calls, delivering less food to calls of a juvenile than to the same individual's calls recorded when a pup. Adult meerkats paid attention to the acoustic structure of begging calls, and ceased provisioning when the call structure changed. We suggest that older pups are unable to produce stimulating begging calls. © 2009 the Association for the Study of Animal Behaviour.
Abstract.
2008
Madden, J.R. (2008). Can bowerbirds be considered to exhibit recognizable cultures?. Animal Cognition, 11, 1-12.
Madden JR (2008). Do bowerbirds exhibit cultures?.
Anim Cogn,
11(1), 1-12.
Abstract:
Do bowerbirds exhibit cultures?
Definitions of what features constitute cultural behaviour, and hence define cultures are numerous. Many seem designed to describe those aspects of human behaviour which set us apart from other animals. A broad definition prescribing that the behaviour is: learned; learned socially; normative and collective is considered to apply to several species of great ape. In this paper, I review observations and experiments covering a suite of different behavioural characteristics displayed in members of the bowerbird family (Ptilonorhynchidae) and ask whether they fulfil these criteria. These include vocalisations, bower design, decoration use, bower orientation and display movements. Such a range of behaviours refutes the suggestion that these species are "one-trick ponies"--a criticism that is often levelled at claims for culture in non-primate species. I suggest that, despite a paucity of data in comparison with primate studies, it could be argued that bowerbirds may be considered to fulfil the same criteria on which we base our use of the term culture when applied to our close relatives, the great apes. If bowerbirds do have cultures, then their unusual natural history makes them a highly tractable system in which questions of social learning and culture can be tackled.
Abstract.
Author URL.
English S, Kunc HP, Madden JR, Clutton-Brock TH (2008). Sex differences in responsiveness to begging in a cooperative mammal.
Biol Lett,
4(4), 334-337.
Abstract:
Sex differences in responsiveness to begging in a cooperative mammal.
In species where young are provisioned by both parents, males commonly contribute less to parental care than females, and are less responsive to variation in begging rates. Similar differences in the care of young occur among adults in cooperative breeders, but fewer studies have investigated whether these are associated with differences in responsiveness. Here, we present results from a playback experiment investigating responsiveness to begging in the meerkat (Suricata suricatta), a cooperatively breeding mammal. Although increased begging rate raised the feeding rate of adults of both sexes, there was no consistent tendency for females to be more responsive than males. However, when we examined changes in the proportion of food items found that were fed to pups (generosity), we found that females were more responsive than males to increased begging rate. These results can be explained in terms of sex differences in dispersal: in meerkats, females are philopatric and receive considerable benefits from investing in young, both directly, by increasing group size, and indirectly, by recruiting helpers if they inherit the breeding position. In addition, they emphasize that generosity provides a more sensitive measure of responsiveness to begging than feeding rate, as it accounts for variation in foraging success.
Abstract.
Author URL.
Manser MB, Madden JR, Kunc HP, English S, Clutton-Brock T (2008). Signals of need in a cooperatively breeding mammal with mobile offspring.
Animal Behaviour,
76(6), 1805-1813.
Abstract:
Signals of need in a cooperatively breeding mammal with mobile offspring
In many bird species with biparental care for young in the nest, hungry chicks beg repeatedly and parents adjust their feeding rate to the call rate of young. Repetitive calling also occurs in fledglings and in some mammals where offspring follow provisioners. It is not yet clear whether, in mobile systems with dispersed young where adults cannot compare the vocal behaviour of all young simultaneously, the calls represent a signal of need. We investigated repetitive begging by cooperatively reared meerkat, Suricata suricatta, pups that foraged with the group. Pups produced two types of begging calls: repeat calls over long periods and high-pitched calls mainly confined to feeding events. Food-deprived pups stayed closer to feeders, and begged for longer and more intensely by calling at a higher rate. Hungry pups increased both the rate of repeat calls, which were given continually, and the number of high-pitched bouts, but adults increased their food allocation only in relation to the rate of repeat calls. Our study indicates that hunger may lead to several changes in vocal behaviour, only some of which may be used by adults to assess need. © 2008 the Association for the Study of Animal Behaviour.
Abstract.
Kelley LA, Coe RL, Madden JR, Healy SD (2008). Vocal mimicry in songbirds.
Animal Behaviour,
76(3), 521-528.
Abstract:
Vocal mimicry in songbirds
Baylis (1982, Acoustic Communication in Birds, Academic Press) decried the serious lack of experimental verification for the various hypotheses proposed to explain vocal mimicry in songbirds. With few exceptions, our understanding of the function and acquisition of this fascinating behaviour seems to have scarcely progressed. We examine the proposed functional explanations and supporting evidence, and summarize advances made since Baylis's (1982) review. We conclude that there is no compelling evidence to support any of the functional hypotheses but, rather, that almost all of the data concerning song mimicry are consistent with the learning mistakes hypothesis, whereby birds learn simple and common sounds, frequently using them in inappropriate contexts. Additionally, many apparently mimicked sounds are calls, not songs, which themselves may not be learned by the models. It is plausible that many examples of call mimicry are, in fact, due to evolutionary convergence. © 2008 the Association for the Study of Animal Behaviour.
Abstract.
2007
Madden JR (2007). Innovation in sexual display.
BEHAVIORAL AND BRAIN SCIENCES,
30(4), 417-+.
Author URL.
2006
Davies NB, Madden JR, Butchart SHM, Rutila J (2006). A host-race of the cuckoo Cuculus canorus with nestlings attuned to the parental alarm calls of the host species.
Proceedings of the Royal Society B: Biological Sciences,
273(1587), 693-699.
Abstract:
A host-race of the cuckoo Cuculus canorus with nestlings attuned to the parental alarm calls of the host species
The common cuckoo has several host-specific races, each with a distinctive egg that tends to match its host's eggs. Here, we show that the host-race specializing on reed warblers also has a host-specific nestling adaptation. In playback experiments, the nestling cuckoos responded specifically to the reed warbler's distinctive 'churr' alarm(given when a predator is near the nest), by reducing begging calls (likely to betray their location) and by displaying their orange-red gape (a preparation for defence). When reed warbler-cuckoos were cross-fostered and raised by two other regular cuckoo hosts (robins or dunnocks), they did not respond to the different alarms of these new foster-parents. Instead, they retained a specific response to reed warbler alarms but, remarkably, increased both calling and gaping. This suggests innate pre-tuning to reed warbler alarms, but with exposure necessary for development of the normal silent gaping response. By contrast, cuckoo chicks of another host-race specializing on redstarts showed no response to either redstart or reed warbler alarms. If host-races are restricted to female cuckoo lineages, then chick-tuning in reed warbler-cuckoos must be under maternal control. Alternatively, some host-races might be cryptic species, not revealed by the neutral genetic markers studied so far. © 2005 the Royal Society.
Abstract.
Kunc, H. Madden, J.R. & Manser, M. (2006). Begging signals in a mobile feeding system: the evolution of different call types. American Naturalist, 170, 617-624.
Madden, J. R. (2006). Innovation in sexual display. Behavioral and Brain Sciences, 301, 417-418.
2005
Madden, J.R. & Davies, N.B. (2005). A host-race difference in begging calls of nestling cuckoos Cuculus canorus develops through experience and increases host provisioning. Proc R Soc London, B 273, 2343-2351.
Davies, N.B. Madden, J.R. Butchart, S.H.M. & Rutila, J. (2005). A host-race of the cuckoo Cuculus canorus with nestlings attuned to the parental alarm calls of the host species. Proc R Soc London, B 273, 693-699.
Endler JA, Madden JR, Robson T, Westcott DA (2005). Animal visual systems and the evolution of color patterns; sensory processing illuminates signal evolution. Evolution, 59(8), 1795-1818.
Madden, J.R. (2005). Inter-population differences exhibited by Spotted Bowerbirds Chlamydera maculata across a suite of male traits and female preferences. Ibis, 148, 425-435.
2004
JMadden, Hauber ME, Kilner RM (2004). Brood parasitic cowbird nestlings use host young to procure resources. Science, 305(5685), 877-879.
Madden JR, Lowe TJ, Fuller HV, Dasmahapatra KK, Coe RL (2004). Local traditions of bower decoration by spotted bowerbirds in a single population.
Animal Behaviour,
68(4), 759-765.
Abstract:
Local traditions of bower decoration by spotted bowerbirds in a single population
Recent work has shown that elaborate secondary sexual traits and the corresponding preferences for them may be transmitted culturally rather than by genetic inheritance. Evidence for such cultural transmission commonly invokes spatial patterns of local similarity, with neighbouring individuals or populations appearing similar to each other. Alternative explanations for local similarity include ecological similarity of neighbouring environments and confounding genetic effects caused by aggregations of kin. We found that bowers built by male spotted bowerbirds, Chlamydera maculata, within a single population showed fine-scale similarities between neighbours in the decorations displayed on them. Such similarities did not covary with local decoration availability, local display environment or kinship and could not be explained by stealing behaviour by neighbours. Instead, we suggest that these similarities are products of local tradition, either culturally transmitted by neighbouring males who regularly inspect neighbours' bowers, or as localized responses to variable individual female preferences. © 2004 the Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
Abstract.
Madden JR, Lowe TJ, Fuller HV, Coe RL, Dasmahapatra KK, Amos W, Jury F (2004). Neighbouring male spotted bowerbirds are not related, but do maraud each other.
Animal Behaviour,
68(4), 751-758.
Abstract:
Neighbouring male spotted bowerbirds are not related, but do maraud each other
Males with elaborate secondary sexual traits can enhance their mating success both by choosing to display at a site that increases the efficacy of their signal and by displaying at a site where the population is structured to provide inclusive fitness benefits via kin selection. Theoretical models and field studies reveal that, across a range of species and especially those with nonresource-based mating systems, males do display with kin. Bowerbirds use a nonresource-based mating system where males show spatial site fidelity and females visit the sites for the purpose of mate choice. However, neighbours can interfere with bower display by marauding (destroying and decoration stealing). Models suggest that local nonaggression pacts provide the best conditional strategy for males, a situation that may be facilitated by kin-mediated inclusive fitness benefits if males displayed together. We used a novel method of calculating relatedness, based on amplified fragment length polymorphism (AFLP), in a population of spotted bowerbirds, Chlamydera maculata, and found no evidence of fine-scale genetic structuring of display sites. Furthermore, males did not display next to kin, but instead an owner's neighbours were those most likely to maraud his bower. Marauders did not discriminate between kin and nonkin as their victims. Such theft and destruction may affect the mating success of the targeted bower owner. © 2004 the Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
Abstract.
Kilner, R.M. Davies, N.B. (2004). Nestling responses to adult food and alarm calls: 1. Species-specific responses in two cowbird hosts. Animal Behaviour, 70, 619-627.
Madden, J.R. Kilner, R.M. & Davies, N.B. (2004). Nestling responses to adult food and alarm calls: 2. Cowbirds and red-winged blackbirds reared by eastern phoebe hosts. Animal Behaviour, 70, 629-637.
Madden JR, Balmford A (2004). Spotted bowerbirds <i>Chlamydera maculata</i> do not prefer rare or costly bower decorations.
BEHAVIORAL ECOLOGY AND SOCIOBIOLOGY,
55(6), 589-595.
Author URL.
2003
Madden JR (2003). Bower decorations are good predictors of mating success in the spotted bowerbird.
Behavioral Ecology and Sociobiology,
53(5), 269-277.
Abstract:
Bower decorations are good predictors of mating success in the spotted bowerbird
Variation in the mating success of males can often be predicted by considering measures of their exaggerated sexual traits. Male spotted bowerbirds Chlamydera maculata build and decorate elaborate structures - bowers - that function in mate choice. I show that numbers of certain decorations correlate with the mating success of the bower owner. Specifically, numbers of Solanum berries used as decorations, accurately predict variation in mating success over 2 years. I show a relationship between changes in rank berry number and changes in rank mating success. These predictive decorations differ from those shown to relate to mating success in another population of spotted bowerbirds, suggesting that the exact form of sexual display may differ between populations of the same species.
Abstract.
Madden, J.R. (2003). Bower decorations are good predictors of mating success in the spotted bowerbird. Behavioral Ecology and Sociobiology, 53, 269-277.
Madden, J.R. Butchart, S.H.M. (2003). Learning fine-tunes a specific response of nestlings to the parental alarms of their own species. Proc R Soc London, B 271, 2297-2304.
Madden, J.R. Lowe, T.J. Fuller, H.V. Dasmahapatra, K. & Coe R.L. (2003). Local traditions of bower decoration by spotted bowerbirds in a single population. Animal Behaviour, 68, 559-565.
Madden, J.R. Endler, J.A. & Jury, F. (2003). Morphological signals of sex and status in spotted bowerbirds. Emu, 104, 21-30.
Madden, J.R. Lowe, T. J. Fuller, H. V. Coe R. L. Dasmahapatra, K. Amos, W. & Jury, F. (2003). Neighbouring male spotted bowerbirds are not related, but do maraud each other. Animal Behaviour, 68, 551-558.
JMadden, Tanner K (2003). Preferences for coloured bower decorations can be explained in a non-sexual context. Animal Behaviour, 65(6), 1077-1083.
Madden, J.R. & Balmford, A. (2003). Spotted bowerbirds do not prefer rare or costly bower decorations. Behavioral Ecology and Sociobiology, 55, 589-595.
2002
Jenkins, M. Green, R.E. & Madden, J. (2002). the Challenge of Measuring Global Change in Wild Nature: Are Things Getting Better or Worse?. Conservation Biology, 17, 20-23.
JMadden (2002). Bower decorations attract females but provoke other male spotted bowerbirds - bower owners resolve this trade-off. Proceedings of the Royal Society B Biological Sciences, 269(1498), 1347-1351.
Balmford A, Bruner A, Cooper P, Costanza R, Farber S, Green RE, Jenkins M, Jefferiss P, Jessamy V, Madden J, et al (2002). Ecology: Economic reasons for conserving wild nature.
Science,
297(5583), 950-953.
Abstract:
Ecology: Economic reasons for conserving wild nature
On the eve of the World Summit on Sustainable Development, it is timely to assess progress over the 10 years since its predecessor in Rio de Janeiro. Loss and degradation of remaining natural habitats has continued largely unabated. However, evidence has been accumulating that such systems generate marked economic benefits, which the available data suggest exceed those obtained from continued habitat conversion. We estimate that the overall benefit:cost ratio of an effective global program for the conservation of remaining wild nature is at least 100:1.
Abstract.
Madden, J.R. (2002). Male spotted bowerbirds preferentially choose, arrange and proffer objects that are good predictors of mating success. Behavioral Ecology and Sociobiology, 53, 263-268.
2001
Madden, J.R. (2001). Bower location by the spotted bowerbird Chlamydera maculata. Emu, 102, 187-193.
Bruner, A. Cooper, P. Costanza, R. (2001). Economic reasons for conserving wild nature. Science, 297, 950-953.
Madden J (2001). Sex, bowers and brains. Proceedings of the Royal Society B Biological Sciences, 268(1469), 833-838.
