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Pumas (Puma concolor) are solitary large carnivores that exhibit high energetic investments while hunting prey that often take multiple days to consume. Therefore, pumas should behave in a way to maximize their energetic gains, including using caching, which is a behavior used by many mammal species to preserve and store food or to conceal it from conspecifics and scavengers to limit their losses. Yet pumas do not always cache their kills. In order to understand caching behavior, we used variables associated with the kills such as prey mass, search time, climate, and habitat to test 20 ecological models (representing four a priori hypotheses: food perishability, resource pulse, consumption time, and kleptoparasitism deterrence) in an information-theoretic approach of model selection to explore factors related to the caching behavior. Models were run with information from tracked radio-collared pumas in California over a 2.5-year period and identified a total of 352 kills. Overall, we documented pumas caching 61.5% of their kills, including 71.6% of Black-tailed Deer (Odocoileus hemionus columbianus), their primary prey in the study area. The model with a quadratic effect of adjusted mass of prey on puma caching probability had all of the empirical support (w = 1.00). Specifically, pumas were most likely to cache intermediate-sized prey, such as yearling and adult female deer, and also fed from cached kills for longer periods of time. Larger prey may be too large to easily cache, making it less energetically efficient—while small prey can often be consumed quickly enough to not require caching. This suggests that intermediate-sized prey may be the optimal size for caching, allowing a puma to feed for multiple days while not greatly increasing energetic output. The hypotheses we tested were not mutually exclusive and pumas caching their prey may occur for several reasons; nevertheless, our study demonstrated that pumas use caching to extend their foraging time and maximize energetic gains when preying on intermediate-sized prey.

© Published by Oxford University Press on behalf of American Society of Mammalogists 2018. Quantifying reproductive parameters is essential for developing effective conservation plans for species of concern; however, studying reproduction in wild settings can be challenging and local data are frequently unavailable. The fisher (Pekania pennanti) is an elusive forest-dwelling carnivore of conservation concern that occurs across much of boreal North America and reaches the southernmost limit of its distribution in the southern Sierra Nevada (SSN) in California. Data on fisher reproduction in this region are limited and applicability of parameters from other areas is uncertain. To clarify how fisher populations in the SSN compare with those elsewhere in North America, we conducted a comprehensive review of available literature on reproduction throughout the species' range in North America. We then compared findings from the review with data we collected during 7 years in the SSN, focusing on the proportion of females reproducing, litter size, and the parturition date. On average across the fisher's range, the proportion of adult females that reproduced was 0.71 (range: 0.40-1.00; n = 16 studies), litter size was 2.5 (range: 1-4; n = 16 studies), and parturition occurred on 25 March (range: 3 March-17 April; n = 16 studies). In our study area, we tracked 42 adult female fishers, 35 of which reproduced and used 257 reproductive dens (74 natal, 175 maternal, 8 early failures); 0.86 of our females attempted denning (range: 0.79-1.0; n = 93 opportunities) and 0.75 were successful (range: 0.64-1.0; n = 91 opportunities monitored through the den season). Mean litter size was 1.57 (range: 1-3; n = 75 litters) and mean parturition date was 30 March (range: 17 March-12 April; n = 69 natal dens initiated). Female fishers at the southern limit of their distribution in the SSN reproduced at a rate comparable to or higher than elsewhere in North America, but average litter size was the lowest reported for the species. Female fishers in the SSN gave birth at similar or later dates than elsewhere in their range. We explore factors that might explain patterns of variation in fisher reproductive parameters and discuss conservation implications of our findings.

Lay SummaryReturning to previously used areas (site fidelity) or place of birth (philopatry) are important behavioral adaptations in many species, with known fitness benefits. The combined population level consequences of site fidelity and philopatry, however, have received little attention. Based on GPS location data and mitochondrial DNA we demonstrate how high levels of fidelity and philopatric behavior in the matrilineage of black-tailed deer can lead to fine-scale population structure and discuss possible implications for population dynamics.

Populations of generalist foragers may in fact be composed of individuals that select different prey. We monitored 9 pumas (Puma concolor) in Chilean Patagonia using Argos–global positioning system (Argos-GPS) technology for a mean of 9.33 months 6 5.66 SD. We investigated 694 areas where puma location data were spatially aggregated, called GPS clusters, at which we identified 433 kill sites and 6 acts of scavenging. Pumas as a population specialized upon guanacos (Lama guanicoe), whereas only 7 of 9 individual pumas specialized upon guanacos. One puma specialized upon domestic sheep (Ovis aries) and 1 upon European hares (Lepus europaeus) in terms of numbers of prey killed. Male and female pumas selected different distributions of prey and pumas exhibited prey selection at both the individual and population level. Three of 9 pumas exhibited selection when we compared individual prey use to prey availability within individual pumas’ home ranges. One puma selected endangered huemul (Hippocamelus bisulcus) and 2 selected sheep. When we compared individual prey use to prey use at the population level, 5 of 9 pumas differed from the population norm. Whereas pumas did not select huemul at the population level, 2 individuals did select huemul. Two individuals also selected domestic sheep, and the influence of these 2 pumas was substantial enough to result in a population-level effect. Our research highlights the need to determine whether pumas exhibit individual foraging variation throughout their range, the extrinsic factors associated with (and possibly influencing) such variation, and how pumas that select rare and less abundant species in multiprey systems impact recovering prey populations.

Conservation of huemul (Hippocamelus bisulcus), an endangered South American deer, is hindered by a lack of quantitative information on its population dynamics. We conducted a 3-year study in Chilean Patagonia to assess the dynamics of huemul by monitoring known individuals. We fitted 55 deer of all sex–age classes with either radiocollars, radio ear tags, or conventional ear tags, and identified 33 additional deer through natural marks. Kaplan–Meier estimates revealed that annual survival of adult females was high and stable (0.94 6 0.07 SD), but survival of female fawns was low and variable (0.13 6 0.18). Predation was the predominant cause of mortality for deer of all age classes. Fertility rates were lower (0.72 6 0.20) than in other cervids of similar size. Simulations of the finite rate of increase (l) suggest that the population is currently stable. Sensitivity analysis showed that any decrease in adult female survival would have drastic effects on l. Consequently, management should maintain high adult survival and improve recruitment. Continued monitoring of individuals is required to provide baseline data for comparison with other populations and to inform recovery strategies of small and fragmented populations. DOI: 10.1644/09-MAMM-A-047.1.

F. Courchamp, L. Berec, J. Gascoigne. 2008. Allee Effects in Ecology and Conservation. Oxford University Press, New York, New York, 272 pp. ISBN 978-0-19-956755- 3, price (paper), $60.00. In the 1930s and 1940s research by Warder C. Allee suggested that individual fitness (or components thereof) could be positively related to population size or density (e.g., Allee 1931). Today referred to as the “Allee effect,” the notion that presence of conspecifics can have positive dynamic consequences and even prevent population extinction remained largely unnoticed for the next 50 plus years. For example, a search using the keyword “Allee effect” in Web of Knowledge returns only 25 publications prior to the year 1990. Since then we have seen a dramatic increase in the number of studies on Allee effects, cumulating in the 1st comprehensive treatment of the topic by Franck Courchamp, Ludek Berec, and Joanna Gascoigne in 2008 (the focus of this book review). Given the current biodiversity crisis, where at least 25% of all mammal species are threatened with extinction (Schipper et al. 2008), and the apparent prevalence of Allee effects in mammals when compared to other vertebrate classes, this book could not have been published at a more opportune time. This is particularly true because those charged with the conservation of threatened species increasingly will be expected to develop and implement suitable management aimed at counteracting observed Allee effects. Chapter 1 is a delight to read. It presents a comprehensive description of the history of research into Allee effects and provides clear, readily accessible definitions to relevant technical terms. Figures are used effectively to illustrate relationships between individual fitness or population growth rates and population density. The single criticism related …