Coyotes expanding into new territories across North America may be driving a surge in Lyme disease.I don't buy it. And the reason I don't buy it is that the places where I and my friends have gotten Lyme disease -- Quantico, Virginia, Bear, Delaware, St. Marys County, Maryland -- have no coyotes but lots of deer and red foxes. I suspect the correlation between the spread of coyotes and the spread of Lyme is an accident of timing.
It’s often deer that municipalities blame for raising the risk of human infection with the tick-transmitted Lyme bacteria. Yet records from the past three decades link rising numbers of Lyme cases not with booming deer populations but with spreading coyotes, says ecologist Taal Levi, now at the Cary Institute of Ecosystem Studies in Millbrook, N.Y.
As coyotes have trotted into new ranges, red foxes have retreated, Levi and his colleagues find. Coyotes don’t pack a landscape as tightly or kill and cache rodents in flush times as foxes do. So a red fox fade-out allows more little rodents to survive, including white-footed mice and others known as hospitable hosts for the Lyme pathogen and the ticks that spread it. This scenario — coyotes in, foxes out, small rodent numbers up — could be fueling the spread of Lyme disease, the researchers suggest online June 18 in Proceedings of the National Academy of Sciences.
Monday, June 25, 2012
Coyotes and Lyme Disease
From Science News: