RAMONA, Calif. - A researcher from San Diego State University has discovered an alarming mystery in the East County, where a sizable part of the native bobcat population is getting sick and dying.
In April 2012, 10News cameras were there as Duke, a 2-year-old bobcat, was released back into the wild just outside Ramona after being treated for parasitic skins mites, or mange.
Duke survived the deadly condition. He may have been the only one.
"I think what we're seeing is an epidemic in a wildlife population," said researcher Megan Jennings.
Jennings, a post-doctoral researcher, who trapped and released Duke, had actually been tagging bobcats to look at their movements.
Remote cameras were set up near paths used by bobcats. Then, Jennings noticed something else.
Photos snapped by those cameras in the Ramona area in the last two years show 19 bobcats emaciated and with fur missing. Those are telltale signs of mange.
Without human intervention, they typically die within months. Jennings was only able to capture one of them for treatment.
The numbers are significant. Those 19 make up about 20 percent of the overall population in the Ramona area.
Jennings brought 10News to a preserve where some of those bobcats were spotted. She says the bobcat population around there is now at risk.
One theory now emerging is that the afflicted bobcats have weakened immune systems after ingesting rodents that had eaten rat poison.
In a similar outbreak in Orange County, researchers from the National Parks Service tell 10News 90 percent of bobcats that died with mange had rat poison in their system.
It is not just bobcats at risk.
"Exposures to rat poisons are very high in coyotes, birds of prey and mountain lions," said Jennings. "That's a real concern."
In Orange County, two mountain lions recently died of mange infections. Both had high levels of the poison.
"The research may be used to change guidelines when it comes to things like rat poison," said Jennings.