Abstract
BackgroundGray wolves (Canis lupus) were reintroduced into Yellowstone National Park (YNP) after a >70 year absence, and as part of recovery efforts, the population has been closely monitored. In 1999 and 2005, pup survival was significantly reduced, suggestive of disease outbreaks.Methodology/Principal FindingsWe analyzed sympatric wolf, coyote (Canis latrans), and red fox (Vulpes vulpes) serologic data from YNP, spanning 1991–2007, to identify long-term patterns of pathogen exposure, identify associated risk factors, and examine evidence for disease-induced mortality among wolves for which there were survival data. We found high, constant exposure to canine parvovirus (wolf seroprevalence: 100%; coyote: 94%), canine adenovirus-1 (wolf pups [0.5–0.9 yr]: 91%, adults [≥1 yr]: 96%; coyote juveniles [0.5–1.5 yrs]: 18%, adults [≥1.6 yrs]: 83%), and canine herpesvirus (wolf: 87%; coyote juveniles: 23%, young adults [1.6–4.9 yrs]: 51%, old adults [≥5 yrs]: 87%) suggesting that these pathogens were enzootic within YNP wolves and coyotes. An average of 50% of wolves exhibited exposure to the protozoan parasite, Neospora caninum, although individuals’ odds of exposure tended to increase with age and was temporally variable. Wolf, coyote, and fox exposure to canine distemper virus (CDV) was temporally variable, with evidence for distinct multi-host outbreaks in 1999 and 2005, and perhaps a smaller, isolated outbreak among wolves in the interior of YNP in 2002. The years of high wolf-pup mortality in 1999 and 2005 in the northern region of the park were correlated with peaks in CDV seroprevalence, suggesting that CDV contributed to the observed mortality.Conclusions/SignificanceOf the pathogens we examined, none appear to jeopardize the long-term population of canids in YNP. However, CDV appears capable of causing short-term population declines. Additional information on how and where CDV is maintained and the frequency with which future epizootics might be expected might be useful for future management of the Northern Rocky Mountain wolf population.
Highlights
Several high-mortality disease outbreaks among carnivore populations have demonstrated the potential for pathogen-induced population declines [1,2,3,4,5,6] and have emphasized the role of infectious disease in carnivore conservation [7,8]
We screened for exposure to canine parvovirus (CPV), canine adenovirus type-1 (CAV-1), canine distemper virus (CDV), and canine herpesvirus (CHV), all of which can inflict morbidity and mortality in canids (Table S1) [13,14,15,16,17,18,19]
Ethics statement All wolves, coyotes, and foxes used in this study were handled in strict accordance with recommendations from the American Society of Mammalogists [22,23], and all animal work was approved by a National Park Service veterinarian, a Yellowstone National Park (YNP) review committee, and by the YNP superintendent
Summary
Several high-mortality disease outbreaks among carnivore populations have demonstrated the potential for pathogen-induced population declines [1,2,3,4,5,6] and have emphasized the role of infectious disease in carnivore conservation [7,8]. These outbreaks have underscored both the need for better baseline data on disease prevalence, and a better understanding of the ecology of disease in wild populations [7,9]. Gray wolves (Canis lupus) were reintroduced into Yellowstone National Park (YNP) after a .70 year absence, and as part of recovery efforts, the population has been closely monitored. In 1999 and 2005, pup survival was significantly reduced, suggestive of disease outbreaks
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
