White-tailed deer scavenging community in a chronic wasting disease-endemic region and considerations for prion movement

Scavengers impact the geographic spread of pathogens through complex interactions that can either decrease or increase the risk of transmission. Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy fatal to cervids and has been detected throughout much of the United States and internationally. Chronic wasting disease prions have long environmental persistence, and some scavengers have been shown to pass infectious CWD prions through their digestive tracts. We designed a study in a CWD-endemic area of northwestern Arkansas, to determine which scavengers routinely fed on white-tailed deer carcasses and therefore have the potential to be involved in movement or sequestration of CWD prions. Using videos from game cameras, we recorded 25 species that visited white-tailed deer carcasses and calculated abundance, presence duration, and feeding rate. American crows had the greatest number of individuals per video (5.33, 95% CI 3.88-7.32), followed by turkey vultures (3.03, 2.21-4.16), and black vultures (2.94, 2.14-4.04). Black vultures had the longest bout duration in minutes (10.46, 8.01-13.67), followed by bald eagles (9.00, 6.88-11.77) and turkey vultures (8.45, 6.47-11.04). Bald eagles (50%, 38-62%), black vultures (49%, 40-58%), and American black bears (45%, 33-56%) spent the greatest proportion of time feeding, respectively. Species rank varied across metrics, but the average of the three measurements indicated that black vultures, bald eagles, and turkey vultures had the greatest potential to ingest and potentially move CWD prions. Our research highlights the need to experimentally evaluate more avian scavengers for the potential to spread infectious prions.