Researchers said the plague -- a flea-borne bacterial disease introduced to North America during the late 1800s -- spreads rapidly across a landscape, causing devastating effects to wildlife and posing risks to people.
The scientists said their new research demonstrates plague continues to affect the black-footed ferret -- one of the most critically endangered mammals in North America -- as well as several prairie dog species, and it does so even when not erupting in epidemic form.
"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 USGS wildlife biologist Dean Biggins, co-author of the study.
Biggins and his colleagues' research indicates plague might be maintained in the wild within colonies of prairie dogs, the primary food of black-footed ferrets, without causing the large-scale, rapid die-off of prairie dogs that is commonly observed. But the scientists say the mechanisms of the bacterium's low-level presence and survival, as well as the absence of a large-scale die-off of prairie dogs, remain under investigation.
The findings are reported in a special issue of the journal Vector-Borne and Zoonotic Diseases.