MILLBROOK, N.Y., June 24 (UPI) -- A decline in foxes, not an increase in the deer population, may be responsible for the explosion of Lyme disease in parts of the United States, researchers say.
Normally, small mammals get infected by the bacteria and ticks get infected by feeding on the mammals. The infected ticks then lay their eggs on deer. Foxes disrupt the chain by feeding on the small mammals, the Milwaukee Journal Sentinel reported Sunday.
"It was thought that deer were the only game in town for ticks," Taal Levi, lead author of the new study and a research fellow at the Cary Institute of Ecosystem Studies in New York, was quoted as saying.
Foxes will kill many small mammals at once, stashing the kill for later, while coyotes are not as efficient predators of small mammals. As the coyote population has expanded, they've interfered with the suppression of Lyme disease rodent hosts.
Researchers, who tracked the number of deer, coyotes and foxes in Wisconsin, Minnesota, Pennsylvania and Virginia, found decreasing numbers of foxes over a 30-year period. Deer abundance and Lyme cases were not related in Wisconsin and other states, the study published in the Proceedings of the National Academy of Sciences said.
One area in western New York with a high fox population was notably devoid of Lyme, the researchers said.