Native camelids as carrion resources for Andean Condors across a spectrum of human-altered landscapes

Vultures are the most threatened group of birds in the world, and their conservation depends on the availability of safe food resources. In South America, the replacement of native camelids by exotic species exposes Andean condors (Vultur gryphus) to dietary toxins (e.g., lead) and direct persecution. To evaluate the importance of native camelids to condor diet across a spectrum of human-altered landscapes in central-western Argentina, we identified prey remains in condor pellets collected at Auca Mahuida (AM, n = 212) and La Payunia (LP, n = 152) reserves, which support camelid populations (9.53 and 12.28 ind./km² ) and ranching (1.85 and 7.89 ind./km²). We compared our results with studies from two contrasting areas: 1) where camelids are functionally extinct (NW Patagonia), and 2) where they are the only ungulates present (San Guillermo National Park, SG). Our results indicate that condors have local dietary patterns largely dictated by availability of large mammalian prey. Camelids dominated pellet content at SG (88%) and LP (77%), represented 40% of the prey consumed in AM and were functionally absent in NW Patagonia (0.4%). Estimated overlap in condor diet was minimum (Pianka index, 0.08) and niche breath was similar (Levin index, 0.07 and 0.09) between SG and NW Patagonia. In contrast, niche breath was highest in reserves with extensive ranching (AM: 0.35, LP: 0.12). Our works shows that wild camelids in reserves still perform an ecological role as food sources for condors, and highlights the value of protected areas and sustainable farming practices for vulture conservation.