SAN FRANCISCO (AP) — An invasion of aggressive lice appears to be behind the balding of deer across California and may even be linked to deer deaths, according to state wildlife officials who are studying the hair loss.
Since 2009, researchers have collected hair and blood samples from more than 600 deer and elk with symptoms ranging from a scruffy-looking coat to almost complete baldness, the San Francisco Chronicle reported Monday.
So far, the hair loss has been linked to an invasive species of biting lice that normally feeds on fallow deer native to Europe and Asia. The deer respond by biting and scratching, which researchers believe could be leading to the hair loss, Greg Gerstenberg, a senior wildlife biologist with the California Department of Fish and Wildlife, told the Chronicle.
Hair-loss syndrome is associated with poor nutritional condition, state wildlife officials say. Researchers also speculate that deer infested with the lice become easy targets of coyotes and mountain lions because they spend so much time grooming, Gerstenberg said.
"While this theory is still under investigation, what we do know is that the louse has impacted migratory populations of California deer, which now have a low fawn survival rate, making it difficult to replenish the herd," Gerstenberg said in a release put out by the state fish and wildlife department.
Researchers want to know why the lice infestations are appearing and fully understand their impacts.
Gerstenberg told the Chronicle he first became aware of the problem in the spring of 2009 when an almost completely hairless deer was found dead in Tuolumne County, on the western slope of the Sierra Nevada. Wildlife officials over a subsequent five-month period found 240 dead balding deer in the mountains outside Yosemite National Park.
The syndrome has been identified in more than a dozen counties.