Nest predators of sagebrush‐obligate songbirds in the Northern Great Basin

Abstract A major cause of reproductive failure in songbirds is nest predation, yet the full suite of predator species and their relative contribution to nest predation are unknown for most species. We identified nest predator species using motion sensor cameras placed near nests of Brewer's sparrow ( Spizella breweri) , sage thrasher ( Oreoscoptes montanus ), and sagebrush sparrow ( Artemisiospiza nevadensis ) in the northern Great Basin, Oregon, USA. We documented 10 nest predator species, which represents a more diverse predator species assemblage than previously documented in the sagebrush ecosystem. Predators included 4 bird species (American kestrel [ Falco sparverius ], common raven [ Corvus corax ], red‐tailed hawk [ Buteo jamaicensis ], and loggerhead shrike [ Lanius ludovicianus ]), 2 reptiles (gopher snake [ Pituophis catenifer ] and western yellow‐bellied racer [ Coluber constrictor mormon ]) and at least 4 mammal species (chipmunk [ Neotamias spp.], ground squirrel [ Urocitellus spp.], badger [ Taxidea taxus ] and bobcat [ Lynx rufus ]). Gopher snakes were the primary predator at sagebrush sparrow nests while avian predators depredated Brewer's sparrow nests most often. Our results reveal a diverse array of predators who utilize different methods of detecting and capturing prey, all of which were native species. The diversity in predators makes it challenging to implement management strategies, such as habitat manipulation or population control. Such management approaches are often difficult to apply effectively to reduce predation risk and enhance the reproductive success of sagebrush‐specialist bird species.