Puma predation subsidizes an obligate scavenger in the high Andes

Abstract

Summary The ungulate–carnivore–vulture complex is a key trophic module of many terrestrial ecosystems, but one that is globally under threat. Few have explored cross‐species dependencies in this module, and the degree to which vultures rely on trophic facilitation by apex carnivores is rarely known and almost never quantified. We investigated the importance of puma Puma concolor predation on its native camelid prey, vicuñas Vicugna vicugna and guanacos Lama guanicoe, in food provisioning for Andean condors Vultur gryphus in the high Andes of north‐western Argentina. We evaluated the origin of wild food sources through carcass surveys. We quantified condor feeding habits via foraging observations and through the analysis of pellet contents and stable isotopes from moulted feathers. Of the 102 fresh camelid carcasses we monitored, nearly all (94%) resulted from puma predation, and the majority (85%) of camelid carcasses used by condors were killed by pumas. Camelids represented 88% of the prey items identified from 183 condor pellets, and isotopic analyses of moulted feathers from 86 individuals identified via multilocus genotyping revealed that camelids and Small livestock were the most important prey items, representing 45–58% and 28–38% of condor assimilated biomass, respectively. Synthesis and applications. Our results show that puma predation plays a key role in the foraging ecology of Andean condors, and highlight the importance of predatory processes that make carrion available to scavengers. We contend that targeting the conservation of ungulate–carnivore–vulture modules, rather than a species‐specific approach, will be a more effective strategy to ensure the long‐term persistence of Andean condors and other obligate scavengers.

Habitat complexity mediates the predator–prey space race

“…, Perrig et al. ), and pumas subsist primarily on vicuñas as prey (Donadio, Middleton, and Smith, unpublished data ). There are no other predator species capable of killing an adult vicuña at the study site.…”

Monitoring vultures in the 21st century: The need for standardized protocols

“…We extracted DNA from 151 feathers, and successfully genotyped 131 samples at three to five species‐specific, neutral markers (probability of identity ˂0.01; Perrig, Donadio, Middleton, & Pauli, ). We identified 89 birds, of which 30% were males (Perrig et al., ). We aged remiges and rectrices feathers (>19 cm, n = 49) according to coloration: 70% of the samples were black, or black and white, and classified as belonging to adults, whereas 30% brown or grey feathers were classified as belonging to immature birds (Alcaide et al., , Data ).…”

“…We collected moulted feathers (12-70 cm long) at the base of roosts and condor feeding sites during summer 2013. We extracted DNA from 151 feathers, and successfully genotyped 131 samples at three to five species-specific, neutral markers (probability of identity ˂0.01; Perrig, Donadio, Middleton, & Pauli, 2017). We identified 89 birds, of which 30% were males (Perrig et al, 2017).…”

The corrupted carnivore: how humans are rearranging the return of the carnivore‐scavenger relationship

“…Here, Andean condors ( Vultur gryphus ) scavenge wild camelid carcasses ( Lama guanicoe and Vicugna vicugna ) killed by pumas ( Puma concolor; Perrig et al. , Donadio et al. ).…”

“…Andean condors rely almost exclusively on camelid carcasses – all condors observed were feeding within utilized camelid carcasses, 85% of which resulted from puma predation, and the majority (88%) of condor diet is camelids (Perrig et al. ). This tri‐trophic relationship was likely widespread prior to the establishment of ranching, especially before large‐scale sheep operations that ultimately covered vast regions of South America.…”