Expanding predator populations could explain an uptick in infections
Coyotes expanding into new territories across North America may be driving a surge in Lyme disease.
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-ou