Chronic Illnesses Less Harmful Among Cooperative Carnivores
Posted on May 28, 2015 16:01
A recent study of gray wolves in the US Yellowstone National Park has found that wild mammals living in a cooperative group can experience a lesser impact from chronic diseases. This is one of the first studies to measure the effect of an infected non-human individual on other members of the group.
The study was led by Emily Almberg, a research scientist at Penn State University, who said, “Our research with wolves illustrates that social groups can help to offset the survival costs of infection with the parasite that causes mange. It suggests that social living might help individuals cope with a variety of other chronic conditions -- including other infections, physical injuries, or non-infectious diseases -- for which having access to supportive care and resources can make a big difference for survival.”
According to the study, wolves that lived alone and were infected with mange had a five times higher death rate than uninfected wolves that were living alone. However, wolves with mange that were living with their pack, which had at least five healthy wolves, had around the same death rate as healthy wolves.
Senior author Peter Hudson, , director of the Huck Institutes of Life Sciences and Willaman Professor of Biology at Penn State, and a professor at the Nelson Mandela Institute in Tanzania, said, “Our hypothesis is that pack-mates are able to offset the survival costs of infection with mange -- and perhaps other infections -- by assisting with food acquisition and territory defense.”
Also, the size of the wolf pack was not a predictor of risk of individuals infected with mange, but there were situations in which social living came with a greater disease transmission risk.