Yellowstone’s colorful wolves: using thermal imaging to study disease

The warm muzzle of the howling wolf is yellow in this thermal image of a captive wolf at the Grizzly and Wolf Discovery Center in West Yellowstone Photo: Courtesy USGSMost wolves in Yellowstone National Park sport a grey or black coat, but new photos of thermal imaging reveal the animals in a captivating rainbow of hues.

The colorful canine displays are the result of recent testing with thermal imaging on wolves at the Grizzly and Wolf Discovery Center. Paul Cross, USGS Disease Ecologist, and Doug Smith, leader of Yellowstone’s Wolf Project, intend to use the technique in an upcoming study to help determine how mange impacts the survival of Yellowstone’s wolves.

Smith, who has led the wolf project in Yellowstone since 1996, hopes this technology will yield some new insights about the pervasive disease, “What we hope to do is learn about how much heat wolves are losing through hair loss from mange, then determine the energy cost of this and see if this may be a factor in whether or not they survive.”

Click on the image to view a thermal video of two wolves (Courtesy USGS)About a quarter of the wolf packs in Yellowstone are afflicted with sarcoptic mange, a highly contagious canine skin disease caused when the mites burrow into the skin causing infections, hair loss, severe irritation and an insatiable desire to scratch. Although the disease itself is not fatal, the resulting hair loss and depressed vigor of the animal can often lead to the potentially life-threatening conditions of hypothermia, malnutrition and dehydration.

The spots of hair lost by mange on the wolves display bright red on the thermal images because of the heat loss, making it easy to detect on the animals. As Cross notes, “Like many mammals adapted to cold environments, wolves are really well insulated.  When they are resting they are sometimes almost invisible on the thermal cameras, which means that very little of their body heat is escaping.”

Beginning in February, the research team will establish remote cameras in the backcountry of Yellowstone National Park to help them better understand the infection rates from year-to-year, the role mange plays in the lives of the wolves, and the reasons why some wolves recover from the disease while others succumb.

The research is being conducted by the USGS Northern Rocky Mountain Science Center in collaboration with the National Park Service, Yellowstone National Park, and the Grizzly and Wolf Discovery Center in West Yellowstone, Montana. For more information visit