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

Abstract

Throughout the world, populations of scavenger birds are declining rapidly with some populations already on the brink of extinction. Much of the current research into the factors contributing to these declines has focused on exposure to drug residues, lead, and other toxins. Despite increased monitoring of these declining populations, little is known about infectious diseases affecting scavenger bird species. To assess potential infectious disease risks to both obligate and facultative scavenger bird species, we performed a serosurvey for eleven potential pathogens in three species of scavenging birds in California: the California condor (Gymnogyps californianus), turkey vulture (Cathartes aura) and golden eagle (Aquila chrysaetos). California condors were seropositive for avian adenovirus, infectious bronchitis virus, Mycoplasma gallisepticum, avian paramyxovirus-2, West Nile virus (WNV) and Toxoplasma gondii. Golden eagles were seropositive for avian adenovirus, Chlamydophila psittaci and Toxoplasma gondii, and turkey vultures were seropositive for avian adenovirus, Chlamydophila psittaci, avian paramyxovirus-1, Toxoplasma gondii and WNV. Risk factor analyses indicated that rearing site and original release location were significantly associated with a positive serologic titer to WNV among free-flying condors. This study provides preliminary baseline data on infectious disease exposure in these populations for aiding in early disease detection and provides potentially critical information for conservation of the endangered California condor as it continues to expand its range and encounter new infectious disease threats.

Scavenger birds exploiting rubbish dumps: Pathogens at the gates

“…However, this lack of difference could also be associated with the fact that black vultures can acquire this pathogen from different bird species in multiple sites, including anthropogenic and wild areas. For instance, black vultures can acquire Chlamydia psittaci when interacting with other bird species that could be infected by this pathogen and may act as carriers such as gulls (Franson & Pearson, ; Harkinezhad, Geens, & Vanrompay, ), Turkey vultures (Cathartes aura) (Straub et al., ), birds of prey or different water birds (Harkinezhad et al., ; Kaleta & Taday, ).…”

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): avian mycoplasmosis (Mycoplasma gallisepticum, M. meleagridis)

“…Hagen et al (2002) found a low seroprevalence against M. gallisepticum in lesser prairie-chickens in Kansas but could not rule out the hypothesis of a non-specific reaction. Straub et al (2015) reported a 1% seroprevalence for M. gallisepticum in free-flying Californian condors and a 57% seroprevalence for captive birds. However, these authors did not report observation of clinical signs on these birds.…”

“…Straub et al. () reported a 1% seroprevalence for M. gallisepticum in free‐flying Californian condors and a 57% seroprevalence for captive birds. However, these authors did not report observation of clinical signs on these birds.…”

Occurrence of antibodies to Toxoplasma gondii in scavenging black vultures (Coragyps atratus) in Brazil

“…The parasite can cause mortality and subclinical infection among many animal species, including birds (DUBEY, 2010). Although there have been reports of T. gondii infection in scavenging birds (ARENE, 1999;SALANT et al, 2013;STRAUB et al, 2015), we are unaware of any reports on T. gondii infection in black vultures. The present study aimed at determining the presence of T. gondii antibodies in wild black vultures (Coragyps atratus) in Brazil.…”

“…Regarding another vulture species, the turkey vulture (Cathartes aura) in the USA, one of the two birds examined presented T. gondii antibodies when tested using the indirect hemagglutination test (FRANTI et al, 1975). Also studying the same species of vultures, in California Straub et al (2015) found 11% positivity (7/66 using a commercial agglutination test (cutoff ≥ 32).…”