Effects of Sarcoptic Mange on Gray Wolves in Yellowstone National Park.
Funding Sources: U.S. Geological Survey, National Park Service, USGS-NPS POBS funding
Collaborators: Paul Cross, USGS Northern Rocky Mountain Science Center; Emily Almberg, Penn State University; Doug Smith, Yellowstone National Park Wolf Project, Adam Munn, Peter Hudson, Andy Dobson, John Heine - Grizzly and Wolf Discovery Center.
Sarcoptic mange is a highly contagious canine skin disease caused by mites that burrow into the skin causing infections, hair loss, severe irritation and an insatiable desire to scratch. The resulting hair loss and depressed vigor of an infected animal leaves them vulnerable to hypothermia, malnutrition and dehydration, which can eventually lead to death. Mange was introduced into the Northern Rockies in 1909 by state wildlife veterinarians in an attempt to help eradicate local wolf and coyote populations. Scientists believe the troublesome mite that causes the disease persisted among coyotes and foxes after wolves were exterminated. Since their reintroduction into the Greater Yellowstone Ecosystem in 1995-96, wolves appeared to be free of mange until 2002. As of March 2014, 2 of 8 known packs in Yellowstone National Park (YNP) have mange, mostly in the Northern Range, and the prevalence within a pack ranges from 25 to 60%.
Wolves are a popular feature for the public visiting YNP and as a result mange in wolves is likely to become a topic of visitor interest. At present limited information is available on the impacts of mange in wolves at both the individual and population levels. We are examining the impacts of sarcoptic mange on the survival, reproduction and social behavior of YNP wolves, as well as document the progression of infection and associated host recovery rates. This project is providing technical assistance to YNP and simultaneously exploring an emerging issue, providing a foundation for future long-term monitoring that will be useful to state and federal management of wolves in the Montana, Wyoming, and Idaho wolf recovery areas.
To help understand the role of mange in the lives of gray wolves, researchers need to understand the costs and extent of infection. Thermal imagery of wolves allows scientists to not only document the extent of hair loss caused by mange, but the actual loss of heat associated with the different stages of infection.
Grizzly and Wolf Discovery Center in Montana
Researchers at NOROCK and their partners used thermal cameras at the Grizzly and Wolf Discovery Center in Montana to assess the amount of heat lost under a range of environmental conditions with and without hair. On the thermal image, "cooler" blue tones indicate less heat emission, while "warmer" red tones indicate a heat emitting source. The color bar on the right is temperature in degrees Celsius.
To simulate hairloss that occurs in the later stages of mange infection, patches are shaved on the wolves (red spot on hind leg) to allow the researchers to measure temperature loss from the hairless patches and compare this with temperature loss from natural fur. By helping out with this research the wolves in the enclosure are helping scientists better understand how mange operates in their wild counterparts throughout the Greater Yellowstone Ecosystem.
Yellowstone National Park
The risk, severity, and duration of infection with mange are highly variable within Yellowstone's wolf population. Thermal imagery is one tools to assist researchers in measuring temperature loss from the mange patches (red) and compare this with temperature loss from natural fur (blues and greens). In addition, field crews attempt to observe or photograph all radio-collared individuals and their pack mates within Yellowstone National Park for the purpose of scoring infection status. Researchers hope to see if there are attributes of individuals or packs that might predispose them towards higher risk, greater severity, or longer duration of infection. To learn more visit, the dynamics and impacts of sarcoptic mange on Yellowstone's wolves.
In the next phase of the project, researchers collaborated with scientists with the Yellowstone Wolf Project to place thermal remote camera near the carcasses of deer and elk in the park to capture wolves feeding on the carcasses and record the extend of mange in the park's wolf packs.
Another novel approach to observe the extent of mange in the wolves of Yellowstone National Park, as well as develop a dynamic photo library of individual wolves within the park, is by citizen science. Researchers with Penn State University, USGS, and the Yellowstone Wolf Project have developed Yellowstone Wolf: Project Citizen Science to assist the project in collecting park visitor photographs of wolves, and accompanying data on date, location, ID (if known), and pack to answer questions about pack composition, individual histories, and individuals' infection status with mange.
All research animals are handled by following the specific requirements of USGS Animal Care and Use policies.
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Almberg, E.S., P.C. Cross, A.P. Dobson, D.W. Smith and P.J. Hudson. 2012. Parasite invasion following host reintroduction: a case of Yellowstone’s wolves. Philosophical Transactions of the Royal Society. 367, 2840-2851. doi: 10.1098/rstb.2011.0369.
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