Guy Cowlishaw

Predicting extinction risk in declining species

What biological attributes predispose species to the risk of extinction? There are many hypotheses but so far there has been no systematic analysis for discriminating between them. Using complete phylogenies of contemporary carnivores and primates, we present, to our knowledge, the first comparative test showing that high trophic level, low population density, slow life history and, in particular, small geographical range size are all significantly and independently associated with a high extinction risk in declining species. These traits together explain nearly 50% of the total between–species variation in extinction risk. Much of the remaining variation can be accounted for by external anthropogenic factors that affect species irrespective of their biology.

Dominance rank and mating success in male primates

The claim that dominance rank determines male mating success in polygamous primate groups is controversial. One argument against the claim is that spurious correlations are often obtained between dominance rank and mating success as a result of the confounding effects of age. Mating data from 32 studies of primate behaviour, totalling 75 study groups, were collated to test this criticism and investigate the determinants of observed variation in the correlation coefficient values. Despite conflicting reports, a reliable positive relationship between male dominance rank and mating success amongst animals of the same age class is seen. Furthermore, the variation in correlation coefficient values is significantly negatively related to the number of males in the group (the single exception being highly dimorphic primate species, where instead the correlation coefficient is positively related to the number of females). The intensity of the effect of the number of males is most severe in seasonal breeders. These results indicate that the relationship between dominance rank and mating success appears to be a function of the level of competition that males face in the group for access to cycling females. Data on genetic paternity indicate that these results hold even for absolute measures of reproductive success.

Spontaneous emergence of leaders and followers in foraging pairs

Animals that forage socially often stand to gain from coordination of their behaviour. Yet it is not known how group members reach a consensus on the timing of foraging bouts. Here we demonstrate a simple process by which this may occur. We develop a state-dependent, dynamic game model of foraging by a pair of animals, in which each individual chooses between resting or foraging during a series of consecutive periods, so as to maximize its own individual chances of survival. We find that, if there is an advantage to foraging together, the equilibrium behaviour of both individuals becomes highly synchronized. As a result of this synchronization, differences in the energetic reserves of the two players spontaneously develop, leading them to adopt different behavioural roles. The individual with lower reserves emerges as the ‘pace-maker’ who determines when the pair should forage, providing a straightforward resolution to the problem of group coordination. Moreover, the strategy that gives rise to this behaviour can be implemented by a simple ‘rule of thumb’ that requires no detailed knowledge of the state of other individuals.

Animal personality: what are behavioural ecologists measuring?

The discovery that an individual may be constrained, and even behave sub‐optimally, because of its personality type has fundamental implications for understanding individual‐ to group‐level processes. Despite recent interest in the study of animal personalities within behavioural ecology, the field is fraught with conceptual and methodological difficulties inherent in any young discipline. We review the current agreement of definitions and methods used in personality studies across taxa and systems, and find that current methods risk misclassifying traits. Fortunately, these problems have been faced before by other similar fields during their infancy, affording important opportunities to learn from past mistakes. We review the tools that were developed to overcome similar methodological problems in psychology. These tools emphasise the importance of attempting to measure animal personality traits using multiple tests and the care that needs to be taken when interpreting correlations between personality traits or their tests. Accordingly, we suggest an integrative theoretical framework that incorporates these tools to facilitate a robust and unified approach in the study of animal personality.

It's time to work together and stop duplicating conservation efforts ...

We strongly support initiatives to produce clear, efficient and practical goals for conservation to guide biodiversity planners and decision-makers in governments, agencies, conventions and non-governmental organizations (NGOs). However, as things stand there is only limited consensus on global conservation priorities at international level. We believe that the time is now right for scientists and practitioners to work together to develop a commonly adopted blueprint for action.

Vulnerability To Predation in Baboon Populations

This study investigates patterns of predation in Papio baboon populations across Africa. Using anecdotal reports collated from the primate and predator literature, the following analyses are conducted. First, the primary predators of baboons are identified. These are shown to be the terrestrial carnivores; in order of importance leopards, lions and hyena. Second, patterns of large felid predation on baboons are investigated in detail. In terms of prey selection, leopards are more likely to take (1) adults than juveniles and (2) males than females. While lion attacks are strictly diurnal, leopards will attack during both the day and night. However, both predators are usually limited to conducting attacks when and/or where visibility is limited. Leopards were about twice as successful as lions at hunting baboons. Nocturnal leopard hunts were more successful than diurnal hunts when twilight cases were excluded; in relation to this, leopard attacks at sleeping sites were more likely to end in prey capture than attacks at waterholes. Finally, patterns of baboon retaliation against predators revealed that males are more likely to retaliate than females and that such behaviour effectively deters predators. Males are particularly aggressive towards leopards, where in 4/11 cases the leopard was killed. These results may help to resolve a number of outstanding controversies regarding the nature of predation risk in baboons, indicating that diurnal predation is a substantial threat, that males are effective at deterring several predator species, particularly leopards, and that predators will successfully attack and capture males.

How Far Do Animals Go? Determinants of Day Range in Mammals

Day range (daily distance traveled) is an important measure for understanding relationships between animal distributions and food resources. However, our understanding of variation in day range across species is limited. Here we present a day range model and compare predictions against a comprehensive analysis of mammalian day range. As found in previous studies, day range scales near the \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

When to use social information: the advantage of large group size in individual decision making

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