Western spotted skunks provide important food web linkages in forest of the Pacific Northwest

There are increasing concerns about the decreasing population trends of small mammalian carnivores around the world. With limited knowledge about their ecology and natural history, small mammal conservation and management remains difficult. To address one of these deficiencies for western spotted skunks (Spilogale gracilis), we investigated their diet in the Oregon Cascades of the Pacific Northwest during 2017 - 2019. We collected 130 spotted skunk scats opportunistically and with detection dog teams and identified prey items using DNA metabarcoding and mechanical sorting. Western spotted skunk diet consisted of invertebrates such as wasps, millipedes, and gastropods, vertebrates such as small mammals, amphibians, and birds, and plants such as Gaultheria, Rubus, and Vaccinium. Diet also consisted of items such as black-tailed deer that were likely scavenged. Comparison in diet by season revealed that spotted skunks consumed more insects during the dry season (June - August) and marginally more mammals during the wet season (September - May). We observed similar diet in areas with no record of human disturbance and areas with a history of logging. Western spotted skunks provide important food web linkages between aquatic, terrestrial, and arboreal systems by facilitating energy and nutrient transfer, and serve important functional roles of seed dispersal and scavenging. Through prey-switching, western spotted skunks may dampen the effects of irruptions of prey, such as wasps during dry springs and summers, which could then provide ecosystem resilience to environmental change.