Last year, National Geographic put a public face to Southern California's lion population when it photographed P-22 walking in front of the Hollywood sign at night. At that time, the animal was majestic looking and in apparent good health.
However, it was announced yesterday that National Park Service (NPS) lion researchers discovered in March that P-22 is now sick with mange, a parasitic disease of the hair and skin which may be the result of rodenticide poisoning.
"You can see on his face that he's sort of scraggly, and his whiskers are sort of scraggly, and his tail is pretty scrawny," said Dr. Seth Riley, a NPS researcher working out of the Santa Monica Mountains National Recreation Area.
"Anti-coagulant rodenticides are designed to kill rodents by thinning the blood and preventing clotting. When people put these bait traps outside their homes or businesses, they may not realize that the poison works its way up the food chain, becoming more lethal as the dose accumulates in larger animals."
Biologists are still trying to figure out the connection between rat poison and getting mange in animals. It's pretty rare for mountain lions to even develop mange. There are only two known cases in the past 12 years, however both those lions ended up dying from rat poisoning.
P-22 is currently back in Griffith Park. He has been treated with a topical treatment - selamectin - but it's unsure whether the treatment will work, or if he'll ever fully recover.
LEFT: Steve Winter's famous photo of P-22 appeared in the December 2013 issue of National Geographic.
RIGHT: During a recent capture P-22 displayed symptoms of mange and tested positive to poison exposure.
Second-generation rodenticides will shortly be removed from the consumer market in California. Too many owls, hawks, foxes and bobcats, and now mountain lions are dying every year from these poisonous materials.
"The best way to keep rodents out of your home, garage or any building is by blocking all the access points rats and mice may use to enter," said California Department of Fish and Wildlife Environmental Scientist Stella McMillin. "It can be as easy as stuffing steel wool into small holes or using a canned foam filler like 'Great Stuff' sold at hardware stores."
Remove things that attract animals, especially food sources such as pet food or children's snacks, that are left outside or accessible to rodents indoors. Rodents aren't the only critters food attracts. It also attracts ants, yellow-jackets, raccoons, opossums and - if you're in coyote, bear or lion country - even more dangerous wild diners.
Make sure your garbage is secured in a solid container with a tight lid and remove anything rodents might use for shelter, such as wood piles. You can discourage voles, which like to "tunnel" in high grass, by keeping your lawn trimmed. Grass cut at two inches is tall enough to conserve some soil moisture but short enough to provide poor shelter for the vole species in California.
If you still see evidence of rodents, use traps to eliminate the existing rats and mice in or around your home. Traps pose little danger to humans and pets when placed in the small spaces rodents frequent. They are also effective, inexpensive and have no harmful side effects. There are also some environmentally friendly pest control companies that use exclusion and trapping methods rather than poison to keep your home free of rodents.
If you take these actions, still have a rodent problem and feel you must use some kind of poison, please use rodenticide products that DO NOT contain the active ingredients brodifacoum, bromadiolone, difethialone or difenacoum. These are the second-generation anticoagulant rodenticides (SGARs) most likely to kill non-target animals.
The California Department of Pesticide Regulation's decision to restrict those four chemicals is based on decades of monitoring studies and mortality incidents. Every monitoring study done in the last 20 years has found widespread exposure of predators and scavengers with SGARs, most commonly brodifacoum.