scientific papers

SCIENTIFIC PAPERS

Browse our collection of recent scientific papers on puma biology and ecology, with an emphasis on impacts and effects at the human-puma interface. Papers are presented unedited in their original form.

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The effects of puma prey selection and specialization on less abundant prey in Patagonia
Mark Elbroch and Heiko U. Wittmer 2013

ABSTRACT: Populations of generalist foragers may in fact be composed of individuals that select different prey. We monitored 9 pumas (Puma concolor) in Chilean Patagonia. 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 one 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. 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. [more...]

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Nuisance Ecology: Do Condors Exact Foraging Costs on Pumas in Patagonia?
Mark Elbroch and Heiko U. Wittmer, 2013

ABSTRACT: Predation risk describes the energetic cost an animal suffers when making a trade off between maximizing energy intake and minimizing threats to its survival. We tested whether Andean condors (Vultur gryphus) influenced the foraging behaviors of a top predator in Patagonia, the puma (Puma concolor), in ways comparable to direct risks of predation for prey. Our data suggested that condors exacted foraging costs on pumas by significantly decreasing puma handling times at carcasses, and that pumas increased their kill rates by 50% relative to those reported for North America to compensate for these losses. Finally, we determined that the relative risks of detection and associated harassment by condors, rather than prey densities, explained puma “giving up times” (GUTs) across structurally variable risk classes in the study area, and that, like many prey species, pumas disproportionately hunted in high-risk, high-resource reward areas. [more...]

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Birth Timing for Mountain Lions; Testing the Prey Availability Hypothesis
Brian D. Jansen and Jonathan A. Jenks, 2012

ABSTRACT: We investigated potential advantages in birth timing for mountain lion (Puma concolor) cubs. We examined cub body mass, survival, and age of natal dispersal in relation to specific timing of birth. We also investigated the role of maternal age relative to timing of births. We captured mountain lion cubs while in the natal den to determine birth date, which allowed for precise estimates of the population birth pulse and age of natal dispersal. A birth pulse occurred during June–August. Body mass of cubs was related to litter size and timing of birth; heaviest cubs occurred in litters of 2, and those born after 1 July. Cubs born within pulse months exhibited similar survival to those born out of the pulse. We found that cubs born April–June dispersed at younger ages than those born after 1 July. There was less variation in birth timing for 1st litters of females than older females. We hypothesize that cubs born after the peak in births of neonate prey are advantaged by the abundance of vulnerable prey and those cubs and mothers realize an evolutionary advantage. [more...]

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Puma spatial ecology in open habitats with aggregate prey
Mark Elbroch and Heiko U. Wittmer, 2012

ABSTRACT: Solitary felids are commonly associated with structurally complex habitats, where their foraging success is attributed to stealth and remaining undetected by competitive scavengers. Research in North America suggests that pumas (Puma concolor), a wide-ranging species found throughout the Americas, conform to the general characteristics of solitary felids and avoid open grasslands with aggregating prey. Researchers hypothesize that pumas are limited to structurally complex habitats in North America because of pressures from other large, terrestrial competitors. We explored the spatial ecology of pumas in open habitat with aggregating prey in Chilean Patagonia, where pumas lack large, terrestrial competitors. We tracked 11 pumas over 30 months (intensive location data for 9 pumas with GPS collars for 9.33 ± 5.66 months each) in an area where mixed steppe grasslands composed 53% of the study area and carried 98% of available prey biomass, to track resource use relative to availability, assess daily movements, quantify home ranges and calculate their density. [more...]

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Table scraps: inter-trophic food provisioning by pumas
Mark Elbroch amd Heiko U. Wittmer, 2012

ABSTRACT: Large carnivores perform keystone ecological functions through direct predation, or indirectly, through food subsidies to scavengers or trophic cascades driven by their influence on the distributions of their prey. Pumas (Puma concolor) are an elusive, cryptic species difficult to study and little is known about their inter-trophic-level interactions in natural communities. Using new GPS technology, we discovered that pumas in Patagonia provided 232 ± 31 kg of edible meat/month/100 km2 to near-threatened Andean condors (Vultur gryphus) and other members of a diverse scavenger community. This is up to 3.1 times the contributions by wolves (Canis lupus) to communities in Yellowstone National Park, USA, and highlights the keystone role large, solitary felids play in natural systems. These findings are more pertinent than ever, for managers increasingly advocate controlling pumas and other large felids to bolster prey populations and mitigate concerns over human and livestock safety, without a full understanding of the potential ecological consequences of their actions. [more...]

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The Garnet Range Mountain Lion Study: Characteristics of a Hunted Population in West-Central Montana
Hugh Robinson and Rich DeSimone, Montana Fish, Wildlife and Parks Wildlife Division, 2011

ABSTRACT: Large carnivores pose a particular challenge in wildlife management. Their importance in ecosystem function is increasingly well documented, while at the same time their potential for conflict with humans is high, resulting in often divergent public opinion and management objectives. Carnivores are widely hunted for recreation, population control, and to reduce conflict, both direct and indirect with humans. In Montana and western North America, mountain lion populations increased and expanded their range during the 1990s. This resulted in more interactions between lions and humans and the general public became more aware of mountain lion presence. Public acceptance of mountain lions was found to vary with lion population growth, and perceived risk. [more...]

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Cougar survival and source-sink structure on Greater Yellowstone's Northern Range
Toni K. Ruth, et. al., 2011

ABSTRACT: We studied survival and causes of mortality of radiocollared cougars (Puma concolor) on the Greater Yellowstone Northern Range (GYNR) prior to (1987–1994) and after wolf (Canis lupus) reintroduction (1998–2005) and evaluated temporal, spatial, and environmental factors that explain variation in adult, subadult, and kitten survival. Our best models for adult and independent subadults indicated that females survived better than males and survival increased with age until cougars reached older ages. Lower elevations and increasing density of roads, particularly in areas open to cougar hunting north of Yellowstone National Park (YNP), increased mortality risks for cougars on the GYNR. Indices of ungulate biomass, cougar and wolf population size, winter severity, rainfall, and individual characteristics such as the presence of dependent young, age class, and use of Park or Wilderness were not important predictors of survival. Kitten survival increased with age, was lower during winter, increased with increasing minimum estimates of elk calf biomass, and increased with increasing density of adult male cougars. [more...]

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Trophic Downgrading of Planet Earth
James A. Estes, et al., Science Magazine, 2011

Until recently, large apex consumers were ubiquitous across the globe and had been for millions of years. The loss of these animals may be humankind’s most pervasive influence on nature. Although such losses are widely viewed as an ethical and aesthetic problem, recent research reveals extensive cascading effects of their disappearance in marine, terrestrial, and freshwater ecosystems worldwide. This empirical work supports long-standing theory about the role of top-down forcing in ecosystems but also highlights the unanticipated impacts of trophic cascades on processes as diverse as the dynamics of disease, wildfire, carbon sequestration, invasive species, and biogeochemical cycles. These findings emphasize the urgent need for interdisciplinary research to forecast the effects of trophic downgrading on process, function, and resilience in global ecosystems. [more...]

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Coexisting with Cougars: Public Perceptions, Attitudes and
Awareness of Cougars on the Urban-Rural Fringe of Calgary, Canada

Clarisse Thornton and Michael S. Quinn, Internet Center for Human–Wildlife Interactions, University of Nebraska, 2009

ABSTRACT: Interactions between humans and cougars have been steadily increasing over the past 20 years largely due to human encroachment into cougar habitat and an increase in the human population. We determined the attitudes, knowledge, and perceptions toward cougars by residents in the urban-rural fringe of Calgary, Alberta, Canada. We found an overall positive attitude toward the presence of cougars in the area. However, residents indicated a low level of knowledge concerning regional wildlife management and wished to be more directly involved. Recommendations included: increasing the awareness of cougars through targeted education, facilitating of stakeholder involvement, developing of proactive cougar management strategies, and exploring adaptive management. [more...]

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Long-Distance Dispersal of a Male Puma in Patagonia
Mark Elbroch, Heiko Wittmer, Cristian Saucedo and Paulo Corti; Wildlife, Fish and Conservation Biology, UC Davis; Conservación Patagónica, Chile; Instituto de Zoología, Universidad Austral de Chile; 2009

ABSTRACT: Pumas have the largest geographic range of any terrestrial mammal in the Americas. Despite this large distribution, pumas are a species of conservation concern and believed in decline across much of their range. Research in North America suggests that dispersal is critical in maintaining connectivity of increasingly fragmented puma populations. Puma dispersal maintains genetic diversity across the landscape and is essential in revitalizing small populations and recolonizing habitats in which local populations have become extinct (i.e., source-sink dynamics). Long distance dispersals by pumas across large tracts of unsuitable habitat have been well recorded in North America. Here we report on a long-distance dispersal event of a male Patagonian puma in South America as revealed by satellite and GPS telemetry. [more...]

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Impacts of Rural Development on Puma Ecology in the Sierra Nevada
Anne Orlando, Ph.D. Dissertation in Ecology at UC Davis, 2008

ABSTRACT: In Western North America, many rural areas are being converted to ranchette style residential development, potentially degrading habitat for large carnivores including pumas, and impacting ecosystem integrity. In a rapidly developing rural region of the Sierra Nevada, I studied the impacts of low-density development on puma habitat utility, behavioral ecology, mortality, and viability. I characterized properties experiencing puma depredation, a major cause of puma mortality in the study region, and compared attributes of properties that had, and had not, experienced depredation. [more...]

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Trophic Cascades Involving Cougar, Mule Deer and Black Oaks in Yosemite National Park
William J. Ripple and Robert L. Beschta, College of Forestry, Oregon State University, 2008

ABSTRACT: Using a historical reconstruction, we discovered a potential trophic cascade involving cougar, mule deer and California black oak in Yosemite National Park in California. Our objective was to determine whether large deer populations in the absence of a top-level carnivore were suppressing tree regeneration. As human visitation increased in the early 1900s and cougar became increasingly scarce, the mule deer population irrupted in the 1920s. In August 2006, we undertook a retrospective study of black oak recruitment (i.e., growth of seedling/sprouts into tall saplings and trees). We similarly inventoried oaks within sites representing refugia from deer browsing. While significantly diminished oak recruitment has occurred since the 1920s in stands accessible to deer, continuous recruitment of oaks was found in refugia sites. We also found less oak recruitment in areas of high human activity near the park’s visitor center, possibly due to behaviorally-mediated effects of lower cougar and higher deer densities. Overall our results are consistent with trophic cascade theory involving large predators, herbivores, and plants. The long-term lack of oak recruitment is also an indicator of a probable loss of biodiversity. [more...]

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Linking a Cougar Decline, Trophic Cascade and Catastrophic Regime Shift in Zion National Park
William J. Ripple and Robert L. Beschta, College of Forestry, Oregon State University, 2006

ABSTRACT: The strength of top-down forces in terrestrial food webs is highly debated as there are few examples illustrating the role of large mammalian carnivores in structuring biotic and abiotic systems. Based on the results of this study we hypothesize that an increase in human visitation within Zion Canyon of Zion National Park ultimately resulted in a catastrophic regime shift through pathways involving trophic cascades and abiotic environmental changes. Increases in human visitors in Zion Canyon apparently reduced cougar densities, which subsequently led to higher mule deer densities, higher browsing intensities and reduced recruitment of riparian cottonwood trees, increased bank erosion, and reductions in both terrestrial and aquatic species abundance. These results may have broad implications with regard to our understanding of alternative ecosystem states where large carnivores have been removed or are being recovered. [more...]