Bubonic Plague

Risk to wildlife

Biology News

Bubonic plague is threatening recovery   efforts for the imperiled Utah prairie dog

Vaccinating a black-footed ferret for plague

Bubonic plague spread to North America in the late 1800s, and shot rapidly across the landscape (see map), devastating wildlife and endangering people as well. Conservation and recovery efforts for the imperiled black-footed ferret and Utah prairie dog are greatly hampered by plague. Eruptions of the disease have wiped out prairie dog colonies in many locations, as well as the ferret populations that depended on them for food.

Black plague map (click to enlarge)

“The impacts of plague on mammal populations remain unknown for all but a few species, but the impact on those species we have studied raises alarms as well as important questions about how plague might be affecting conservation efforts in general,” said Dean Biggins, a wildlife biologist with the U.S. Geological Survey and co-author of two papers in the special issue.

Biggins’ research shows plague can be maintained in colonies of wild prairie dogs, the main food of black-footed ferrets, without causing rapid die-offs of the prairie dogs themselves. The mechanisms of the bacterium’s low-level presence and survival, as well as the absence of large-scale die-offs among the prairie dogs, remain under investigation.

“The overall difficulty of detecting plague in the absence of a large-scale die-off serves as a warning for those dedicated to wildlife conservation and human health,” Biggins said. “Hazards from plague may exist even where there have never been epidemics that caused widespread and readily detectable levels of mortality among local rodents such as prairie dogs,” he explained.

Two years ago, for example, a National Park Service employee in Arizona died of plague contracted from an infected cougar that he had found dead, even though plague had not been observed in local prairie dog populations.

The special issue covers how bubonic plague persists in the wild, the role of rodents and other hosts in disease transmission, diagnostic techniques, factors that affect the occurrence and spread of plague, effects on wildlife populations, as well as disease management and control.