Seroepidemiologic Survey of Potential Pathogens in Obligate and Facultative Scavenging Avian Species in California

Straub, Mary H.; Kelly, Terra R.; Rideout, Bruce A.; Eng, Curtis; Wynne, Janna; Braun, Josephine; Johnson, Christine K.

Worldwide, scavenging bird populations are rapidly declining [1] [2] [3] . Currently over half of the world's vulture species are facing the threat of extinction [4] with several populations having already decreased by over 95% [5, 6] . In Africa, eight species of vulture have declined by an average of 62% in recent decades [7] . Scavenging bird species provide vital ecosystem services including decreasing the spread of disease, recycling of nutrients through the environment and reducing the costs associated with carcass disposal [8, 9] . As scavenging bird populations decline throughout the world, infectious diseases, including rabies, plague and canine distemper, are expected to increase [10] [11] [12] . Recent attention has focused on pharmaceutical drug residues, poisons aimed at predators, lead from ammunition and other toxins in animal remains serving as food resources [13] [14] [15] [16] [17] [18] [19] , which all contribute to mortality, in addition to other causes of death such as human persecution and utility line collision [4, 16, 20] . Infectious diseases have been a less common focus of investigations and there are relatively few accounts of infectious diseases as a direct cause of mortality in avian scavengers. West Nile virus (WNV) was determined to be the cause of death for two California condors (Gymnogyps californianus) in California [16] and Newcastle disease virus has been implicated in the death of a bearded vulture (Gypaetus barbatu) in Israel [21] . Given the ongoing declines in scavenging birds, baseline information on infectious disease exposure will be useful for monitoring population health, investigating future disease-related epidemics, and informing conservation efforts needed for species in decline.