The effects of puma prey selection and specialization on less abundant prey in Patagonia

Elbroch, L. Mark; Wittmer, Heiko

doi:10.1644/12-mamm-a-041.1

Cited by 76 publications

(97 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This was likely due to our methods rather than the ecological reality of the system, and a more intensive field effort may have yielded different results (Knopff et al 2010;Elbroch and Wittmer 2013b). Because we employed the night > 1 model to quantify kill rates, we limited our ability to detect small prey or large prey when large competitors displaced cougars from their kills (Elbroch and Wittmer 2013a).…”

Section: Discussionmentioning

confidence: 99%

Recolonizing wolves influence the realized niche of resident cougars

et al. 2015

View full text Add to dashboard Cite

Background: Niche differentiation may betray current, ongoing competition between two sympatric species or reflect evolutionary responses to historic competition that drove species apart. The best opportunity to test whether ongoing competition contributes to niche differentiation is to test for behavioral shifts by the subordinate competitor in controlled experiments in which the abundance of the dominant competitor is manipulated. Because these circumstances are difficult to coordinate in natural settings for wide-ranging species, researchers seize opportunities presented by species reintroductions. We tested for new competition between reintroduced wolves and resident cougars in the Southern Yellowstone Ecosystem to assess whether wolves might be impacting the realized niche of sympatric cougars. Results: Between 2002 and 2012, a period during which wolves increased from 15 to as high as 91 in the study area, cougars significantly increased the percentage of deer and decreased the percentage of elk in their diet in summer. Our top models explaining these changes identified elk availability, defined as the number of elk per wolf each year, as the strongest predictor of changing cougar prey selection. Both elk and deer were simultaneously declining in the system, though deer more quickly than elk, and wolf numbers increased exponentially during the same time frame. Therefore, we concluded that prey availability did not explain prey switching and that competition with wolves at least partially explained cougar prey switching from elk to deer. We also recorded 5 marked cougar kittens killed by wolves and 2 more that were killed by an undetermined predator. In addition, between 2005 and 2012, 9 adult cougars and 10 cougar kittens died of starvation, which may also be in part explained by competition with wolves. Conclusions: Direct interspecific predation and shifting cougar prey selection as wolves increased in the system provided evidence for competition between recolonizing wolves and resident cougars. Through competition, recolonizing wolves have impacted the realized niche of resident cougars in the Southern Yellowstone Ecosystem (SYE), and current resident cougars may now exhibit a realized niche more reflective of an era when these species were previously sympatric in the Yellowstone Ecosystem.

show abstract

Section: Discussionmentioning

confidence: 99%

Recolonizing wolves influence the realized niche of resident cougars

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The ages of huemul up to 3.5 years old were estimated using tooth eruption sequences. For small prey, we assumed 4 kg for European hares (Elbroch and Wittmer 2013b), 2 kg for Patagonian haired armadillos (Chaetophractus villosus) (Iriarte 2008), 9 kg for culpeo foxes (Iriarte 2008), and 6.4 kg for upland geese (Chloephaga picta) (Todd 1996).…”

Section: Estimating Prey Weightsmentioning

confidence: 99%

“…In contrast, published kill rates quantified through field efforts have been highly variable and rarely align with model predictions (Laundré 2008, Knopff et al 2010, Ruth and Murphy 2010b. Until recently, puma field research has been almost entirely reliant upon triangulation of animals tagged with VHF transmitters over multiple days, a method that likely underestimates actual kill rates because of the difficulty in finding kills at which pumas remained for less than 24 hours (Merrill et al 2010, Elbroch andWittmer 2013b). Recent GPS technology, however, has revolutionized research methods on the foraging ecology of cryptic carnivores (Knopff et al 2010, Merrill et al 2010, Elbroch and Wittmer 2013b.…”

Section: Introductionmentioning

confidence: 99%

“…Recent GPS technology, however, has revolutionized research methods on the foraging ecology of cryptic carnivores (Knopff et al 2010, Merrill et al 2010, Elbroch and Wittmer 2013b. New puma research based on field investigations of GPS clusters has suggested that actual puma kill rates are significantly higher than those predicted by puma energetic models (Knopff et al 2010, Elbroch andWittmer 2013b), despite improved data on puma activity patterns and associated refinements of puma energetic models (Laundré 2005).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The difference between killing and eating: ecological shortcomings of puma energetic models

et al. 2014

Self Cite

View full text Add to dashboard Cite

Abstract. Bioenergetic modeling is employed to estimate the energetic demands of many cryptic carnivores and their kill rates needed to meet their energetic requirements. We tested two prevalent assumptions driving energetic modeling of predator kill rates: (1) morphological and physiological information (weight, energetic demands of activity patterns) of individual predators are sufficient to accurately predict their kill rates, and (2) kill and consumption rates are equivalent (meaning that carnivores consume all of what they kill). We did this by testing whether two independent energetic models accurately predicted puma (Puma concolor) kill and consumption rates in three study systems in North and South America with variable ecology, including climate and prey assemblages. Our results demonstrated that current puma energetic models drastically underestimate actual puma kill rates quantified through intensive field monitoring. We concluded that puma energetic models more realistically estimate puma consumption rates needed to meet metabolic requirements. Puma kill rates determined from field efforts were not explained by puma weight (in kg) or activity patterns (in distance traveled), which were the variables used in energetic models. Our kill rates in kg/day determined from field investigations of GPS clusters were the highest reported to date and statistically equivalent across three distinct ecosystems, a range of puma characteristics, variable lengths of monitoring, variable daily distances traveled, and across systems with 1-3 ungulate prey. In contrast, puma kill rates in ungulates/ week differed across study areas, suggesting that kill rates described in kilograms per day are better suited for comparing puma kill rates across systems while kill rates in terms of ungulates per unit time are better suited for modeling predator-prey dynamics for a particular ecosystem. Based on these results we concluded that energetic models using morphological and physiological variables alone were insufficient to predict kill rates, and proposed that rather than focusing future research on refining current energetic models, future research should be directed at understanding the behavioral ecology driving carnivore kill rates.

show abstract

“…(Fig. 1b), e incluyen ambientes ecotonales de estepa y bosques fríos de lenga Nothofagus pumilio (Krasser, 1896), además de comunidades arbustivas de menor altura compuestas por ñirre Nothofagus antarctica (Oerst, 1871) y calafate Berberis microphylla (Forst, 1787) (Elbroch & Wittmer, 2013a). El clima característico es continental trasandino con degeneración esteparia, gran amplitud térmica con una media anual de 8° C y precipitaciones anuales cercanas a 800 mm (Tome et al, 2007).…”

Section: Palabras-claveunclassified

Hábitos alimenticios de poblaciones periféricas de Zaedyus pichiy y Chaetophractus villosus (Cingulata, Chlamyphoridae) en la Patagonia chilena

Arriagada

Baessolo

Saucedo

et al. 2017

Iheringia, Sér. Zool.

View full text Add to dashboard Cite

RESUMEN En Chile los armadillos Zaedyus pichiy (Desmarest, 1804) y Chaetophractus villosus (Desmarest, 1804) tienen poblaciones periféricas restringidas a planicies de altura y estepa patagónica en la vertiente occidental de la Cordillera de los Andes, donde además han sido escasamente estudiadas. En este trabajo entregamos información sobre los hábitos alimenticios de ambas especies de armadillos, obtenida mediante el análisis de heces colectadas en dos áreas de la región de Aysén, Patagonia chilena. En 38 heces de Z. pichiy identificamos dos taxones de plantas, seis de invertebrados y cuatro de vertebrados, mientras que en 72 heces C. villosus identificamos tres, nueve y cuatro taxones de las mismas categorías. En ambas especies de armadillos los invertebrados fueron la categoría más diversa y con mayor frecuencia de ocurrencia, siendo Coleoptera, Orthoptera y Hemiptera los grupos mejor representados en términos de abundancia. Entre los vertebrados se observó mayor frecuencia de restos del camélido Lama guanicoe (Müller, 1776) y el lagomorfo Lepus europaeus (Pallas, 1778). El análisis de rarefacción muestra que la riqueza de taxones fue mayor en C. villosus que en Z. pichiy, y el índice de Pianka indica que no existió un solapamiento trófico significativo entre especies de armadillos. Nuestras observaciones indican que poblaciones periféricas de ambas especies de armadillos muestran dietas omnívoras oportunistas, con un mayor consumo de invertebrados y plantas; además, sugieren que C. villosus se desarrolla en un rango ambiental más amplio, con una dieta más diversa y mayor presencia de esta especie en ambas áreas de estudio.

show abstract

The effects of puma prey selection and specialization on less abundant prey in Patagonia

Cited by 76 publications

References 40 publications

Recolonizing wolves influence the realized niche of resident cougars

Recolonizing wolves influence the realized niche of resident cougars

The difference between killing and eating: ecological shortcomings of puma energetic models

Hábitos alimenticios de poblaciones periféricas de Zaedyus pichiy y Chaetophractus villosus (Cingulata, Chlamyphoridae) en la Patagonia chilena

Contact Info

Product

Resources

About