Male phenotypic diversity experienced during ontogeny mediates female mate choice in guppies

This is the author accepted manuscript. The final version is available from Oxford University Press via the DOI in this record.Early social experience can be important in shaping female mate choice. Previous work has shown that females adjust their decisions based on the distribution of male sexual trait values encountered during development. However, other phenotypic features could be important in the formation of mate preferences if, for example, they provide additional information about the males available. Here, we examined how the level of overall phenotypic variance (independent of trait values) experienced during ontogeny, mediated female choice in guppies, Poecilia reticulata. Developing females were reared with males either all different in colouration or all similar in colouration or with adult females representing high variance, low variance and no experience of male variance respectively. We found that females were more sexually responsive when reared with females only than in either of the male treatments. When reared with males, responsiveness was greater in the low-variance compared to the high variance treatment. Moreover, females had stronger sexual preferences following rearing in the high variance compared to the low variance condition. In turn, males switched mating tactics, increasing the rate of coerced copulation attempts when facing choosier females, possibly to balance the loss in mating opportunities. Taken together, these results demonstrate the adaptive plasticity of female mating decisions and the dynamic selection pressures they might impose on the evolution of male sexual traits, potentially contributing to the maintenance of the extreme polymorphism found in male colour patterns.This work was supported by the University of Exeter through an Exeter Graduate Fellow studentship

Evaluating the social networks of four flocks of captive flamingos over a five-year period: Temporal, environmental, group and health influences on assortment

This is the author accepted manuscript. The final version is avilable from Elsevier via the DOI in this recordFlamingos are well known for their gregarious habits and aggregations in large flocks, but evaluation of the mechanisms behind social grouping remain poorly understood. Captive birds provide a useful model for investigating aspects of social choice in highly gregarious, long-lived species. Animals invest in social relationships that convey fitness benefits and bonds can be long-lasting. For some species, field-based measurement of social networks can be difficult. Captive populations therefore provide a useful alternative for measuring social choices. Data were collected on flamingos at WWT Slimbridge Wetland Centre from 2013 to 2016 and compared to data from 2012. For three flocks, associations were analysed along with individual foot health scores to identify any relationship between health and social behaviour. Long-term partnerships were present in all flocks; preferred associates noted in 2012 were present in 2016. Matrix correlations across years were positive; arrangements of dyads, trios and quartets with higher ties strengths were visible at the beginning and end of the study. Both male-male and female-female bonds were stable over time. All flamingos were more frequently seen socialising than solitary; those in the largest flock showed the highest occurrence of social behaviour (irrespective of enclosure size differences). The number of connections realised from all available within a network was significantly influenced by season. Foot health did not predict associations in these three flamingo networks. Our results indicate that flamingo societies are complex (i.e. formed of long-standing preferential partnerships and not loose, random connections) and the impact of flock size and environment on sociality should be investigated further. These results are helpful for those working with captive flamingos to consider the number of birds housed so that an array of opportunities for choice of associate and/or breeding partner are available in zoo-housed flocks

Ecological knowledge, leadership, and the evolution of menopause in killer whales

This is the final version of the article. Available from Elsevier via the DOI in this record.There is another record in ORE for this publication: http://hdl.handle.net/10871/16488Classic life-history theory predicts that menopause should not occur because there should be no selection for survival after the cessation of reproduction [1]. Yet, human females routinely live 30 years after they have stopped reproducing [2]. Only two other species-killer whales (Orcinus orca) and short-finned pilot whales (Globicephala macrorhynchus) [3, 4]-have comparable postreproductive lifespans. In theory, menopause can evolve via inclusive fitness benefits [5, 6], but the mechanisms by which postreproductive females help their kin remain enigmatic. One hypothesis is that postreproductive females act as repositories of ecological knowledge and thereby buffer kin against environmental hardships [7, 8]. We provide the first test of this hypothesis using a unique long-term dataset on wild resident killer whales. We show three key results. First, postreproductively aged females lead groups during collective movement in salmon foraging grounds. Second, leadership by postreproductively aged females is especially prominent in difficult years when salmon abundance is low. This finding is critical because salmon abundance drives both mortality and reproductive success in resident killer whales [9, 10]. Third, females are more likely to lead their sons than they are to lead their daughters, supporting predictions of recent models [5] of the evolution of menopause based on kinship dynamics. Our results show that postreproductive females may boost the fitness of kin through the transfer of ecological knowledge. The value gained from the wisdom of elders can help explain why female resident killer whales and humans continue to live long after they have stopped reproducing.This research was funded by a Natural Environment Research Council grant (NE/K01286X/1) to D.P.C., D.W.F., and M.A.C

Diversity and consequences of social network structure in toothed whales

This is the final version. Available on open access from Frontiers Media via the DOI in this recordData availability statement: The database of studies generated for this study can be found in the supplemental material.Toothed whales (suborder Odontoceti) are highly social, large brained mammals with diverse social systems. In recent decades, a large body of work has begun investigating these dynamic, complex societies using a common set of analytical tools: social network analysis. The application of social network theory to toothed whales enables insight into the factors that underlie variation in social structure in this taxon, and the consequences of these structures for survival, reproduction, disease transmission, and culture. Here, we perform a systematic review of the literature regarding toothed whale social networks to identify broad patterns of social network structure across species, common drivers of individual social position, and the consequences of network structure for individuals and populations. We also identify key knowledge gaps and areas ripe for future research. We recommend that future studies attempt to expand the taxonomic breadth and focus on standardizing methods and reporting as much as possible to allow for comparative analyses to test evolutionary hypotheses. Furthermore, social networks analysis may provide key insights into population dynamics as indicators of population health, predictors of disease risk, and as direct drivers of survival and reproduction.Natural Environment Research Council (NERC

Reduced older male presence linked to increased rates of aggression to non-conspecific targets in male elephants

This is the author accepted manuscript. The final version is available from the Royal Society via the DOI in this recordMales in many large mammal species spend a considerable portion of their lives in all-male groups segregated from females. In long-lived species, these all-male groups may contain individuals of vastly different ages, providing the possibility that behaviours such as aggression vary with the age demographic of the social environment, as well as an individual’s own age. Here, we explore social factors affecting aggression and fear behaviours in non-musth male African elephants (Loxodonta africana) aggregating in an all-male area. Adolescent males had greater probabilities of directing aggressive and fearful behaviours to non-elephant targets when alone compared to when with other males. All males, regardless of age, were less aggressive toward non-elephant targets, e.g., vehicles and non-elephant animals, when larger numbers of males from the oldest age cohort were present. Presence of older males did not influence the probability that other males were aggressive to conspecifics or expressed fearful behaviours toward non-elephant targets. Older bulls may police aggression directed toward non-elephant targets, or may lower elephants’ perception of their current threat level. Our results suggest male elephants may pose an enhanced threat to humans and livestock when adolescents are socially isolated, and when fewer older bulls are nearby.Leverhulme TrustExplorers ClubWilderness Wildlife TrustElephants for AfricaIDEAWIL

The application of statistical network models in disease research

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Host social structure is fundamental to how infections spread and persist, and so the statistical modelling of static and dynamic social networks provides an invaluable tool to parameterise realistic epidemiological models. We present a practical guide to the application of network modelling frameworks for hypothesis testing related to social interactions and epidemiology, illustrating some approaches with worked examples using data from a population of wild European badgers Meles meles naturally infected with bovine tuberculosis. Different empirical network datasets generate particular statistical issues related to non-independence and sampling constraints. We therefore discuss the strengths and weaknesses of modelling approaches for different types of network data and for answering different questions relating to disease transmission. We argue that statistical modelling frameworks designed specifically for network analysis offer great potential in directly relating network structure to infection. They have the potential to be powerful tools in analysing empirical contact data used in epidemiological studies, but remain untested for use in networks of spatio-temporal associations. As a result, we argue that developments in the statistical analysis of empirical contact data are critical given the ready availability of dynamic network data from bio-logging studies. Furthermore, we encourage improved integration of statistical network approaches into epidemiological research to facilitate the generation of novel modelling frameworks and help extend our understanding of disease transmission in natural populations.M.J.S. is funded by a NERC standard grant (NE/M004546/1) awarded to R.A.M., D.P.C., D.J.H. and M.B., with the APHA team at Woodchester Park, UK (lead scientist is R.J.D.) as project partners

Space-use patterns highlight behavioural differences linked to lameness, parity, and days in milk in barn-housed dairy cows

This is the author accepted manuscript. The final version is available from Public Library of Science (PLoS) via the DOI in this record.Lameness is a key health and welfare issue affecting commercial herds of dairy cattle, with potentially significant economic impacts due to the expense of treatment and lost milk production. Existing lameness detection methods can be time-intensive, and under-detection remains a significant problem leading to delayed or missed treatment. Hence, there is a need for automated monitoring systems that can quickly and accurately detect lameness in individual cows within commercial dairy herds. Recent advances in sensor tracking technology have made it possible to observe the movement, behaviour and space-use of a range of animal species over extended time-scales. However, little is known about how observed movement behaviour and space-use patterns in individual dairy cattle relate to lameness, or to other possible confounding factors such as parity or number of days in milk. In this cross-sectional study, ten lame and ten non-lame barn-housed dairy cows were classified through mobility scoring and subsequently 55 tracked using a wireless local positioning system. Nearly 900,000 spatial locations were recorded in total, allowing a range of movement and space-use measures to be determined for each individual cow. Using linear models, we highlight where lameness, parity, and the number of days in milk have a significant effect on the observed space-use patterns. Non-lame cows spent more time, and had higher site fidelity (on a day-to-day basis they were more likely to revisit areas they had visited previously), in the feeding area. Non-lame cows also had a larger full range size within the barn. In contrast, lame cows spent more time, and had a higher site-fidelity, in the cubicle (resting) areas of the barn than non-lame cows. Higher parity cows were found to spend more time in the right-hand-side area of the barn, closer to the passageway to the milking parlour. The number of days in milk was found to positively affect the core range size, but with a negative interaction effect with lameness. Using a simple predictive model, we demonstrate how it is possible to accurately determine the lameness status of all individual cows within the study using only two observed space-use measures, the proportion of time spent in the feeding area and the full range size. Our findings suggest that differences in individual movement and space-use behaviour could be used as indicators of health status for automated monitoring within a Precision Livestock Farming approach, potentially leading to faster diagnosis and treatment, and improved animal welfare for dairy cattle and other managed animal species

Seasonal variation in daily patterns of social contacts in the European badger Meles meles

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Social interactions among hosts influence the persistence and spread of infectious pathogens. Daily 20 and seasonal variation in the frequency and type of social interactions will play an important role in 21 disease epidemiology, and alongside other factors may have an influence on wider disease dynamics 22 by causing seasonal forcing of infection, especially if the seasonal variation experienced by a 23 population is considerable. We explored temporal variation in within-group contacts in a high-24 density population of European badgers Meles meles naturally-infected with bovine tuberculosis. 25 Summer contacts were more likely and of longer duration during the daytime, while the frequency 26 and duration of winter contacts did not differ between day and night. In spring and autumn within-27 group contacts peaked at dawn and dusk, corresponding with when they were of shortest duration 28 with reduced potential for aerosol transmission of pathogens. Summer and winter could be critical 29 for bovine tuberculosis transmission in badgers, due to the high frequency and duration of contacts 30 during resting periods, and we discuss the links between this result and empirical data. This study 31 reveals clear seasonality in daily patterns of contact frequency and duration in species living in stable 32 social groups, suggesting that changes in social contacts could drive seasonal forcing of infection in 33 wildlife populations even when the number of individuals interacting remains similar.MJS is funded by NERC grant NE/M004546/1 awarded to RAM, DPC, DJH and MB, with RJD and the 386 APHA team at Woodchester Park, UK as project partners. Data were collected for NW’s PhD, funded 387 by Defra. We thank Jared Wilson-Aggarwal and two anonymous reviewers for useful comments and 388 Keith Silk for providing the photograph for Figure 1

Intraspecific variation in inhibitory motor control in guppies, Poecilia reticulata

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordData availability: Processed data for the test phase and the R script used to analyse them can be found at https://osf.io/vy3s2/?view_only=ca4dcf67faef431897337c140fc8b8f3Inhibitory control (IC) is the ability to overcome impulsive or prepotent but ineffective responses in favour of more appropriate behaviours. The ability to inhibit internal predispositions or external temptations is key to cope with a complex and variable world. Traditionally viewed as cognitively demanding and a main component of executive functioning and self-control, IC was historically examined in only a few species of birds and mammals but recently a growing number of studies has shown that a much wider range of taxa rely on IC. Furthermore, there is growing evidence that inhibitory abilities may vary within species at the population and individual levels owing to genetic and environmental factors. Here we use a detour-reaching task, a standard paradigm to measure motor inhibition in non-human animals to quantify patterns of inter-individual variation in IC in wild-descendant female guppies, Poecilia reticulata. We found that female guppies displayed inhibitory performances that were, on average, half as successful as the performances reported previously for other strains of guppies tested in similar experimental conditions. Moreover, we showed consistent individual variation in the ability to inhibit inappropriate behaviours. Our results contribute to the understanding of the evolution of fish cognition and suggest that IC may show considerable variation among populations within a species. Such variation in IC abilities might contribute to individual differences in other cognitive functions such as spatial learning, quantity discrimination, or reversal learning.University of ExeterEuropean Union Horizon 202

Post-fertile Lifespan in Female Primates and Cetaceans

This is the author accepted manuscript. The final version is available from Springer via the link in this recordPopular and scientific interest in menopause in humans has led to increased interest in the extent of post-fertile life in other animals, particularly in long lived social species such as other primates and cetaceans. Information on maximum life span achieved, and age at last birth are available from long-term observations of known individuals from 11 primate species in the wild. Comparable information from wild cetaceans are more difficult to obtain, however there are relevant fisheries data, as well as a small number of long-term individual-based studies. Using post-reproductive representation (PrR) as a population measure of post-fertile lifespan that allows comparisons across populations and species, this review confirms that among primates, only humans have a maximum lifespan significantly longer that 50 years, and only human female life history includes a significant post fertile stage of life. We conclude that although a prolonged post-fertile stage of life is very rare in mammals, it does occur in some exceptionally long lived taxa, such as humans and in resident killer and short-finned pilot whales. Thus menopause evolved independently at least three times in mammals and the reasons for its evolution may differ in different lineages