Another of Area’s Mountain Lions Dies—Fight Led to Infection

• Concern Also Grows that Widespread Use of Rodenticides Is Impacting Local Wildlife

BY HANS LAETZ

A horrific cat fight in Tuna Canyon several weeks ago has left another juvenile mountain lion dead and convinced National Park Service wildlife experts that there is at least one unknown local mountain lion and two radio-tagged lions ranging in the Santa Monica Mountains.

But officials worry it is possible that at least two native pumas, or cougars, have been killed by poisons that entered the food chain via humans leaving bait out for rodents, which were eaten by coyotes, which in turn were eaten by the big cats. Riley said the effects of the widespread use of these poisons on wildlife is an area that has not been adequately studied.

The mountain lion fight two months ago in Tuna Canyon, in the hills above Big Rock, involved a previously unknown animal and P-8, one of four cubs who were born two years ago in the hills near Malibu Creek.

“P-8 died of an infection, caused by the wounds suffered in the fight,” said Seth Riley, an adjunct UCLA professor and wildlife expert with the Santa Monica Mountains National Recreation Area. “But we know it wasn’t P-1.”

The cubs’ father, P-1, has killed the cubs’ mother and two of the cubs in territorial disputes. P-1, a highly territorial, 140-pound alpha male, has mostly been ranging in the hills of Zuma, Trancas and Decker canyons west to the Boney Mountain and Point Mugu area, feasting on deer and avoiding humans.

“P-1 was out at Point Mugu during the fight,” Riley said. The locations are 30 miles apart.

A DNA lab at UCLA analyzed residual material from the fight found in P-8’s claws, and determined it to be from another, until now, unknown mountain lion.

“Whether he came in across the 101 freeway, or whether it was here in the Santa Monicas all along, we don’t know,” Riley said. “These are big mountains and they’re full of deer, and it’s possible we may have some cats up there that we don’t know about.”

Two other cats have been tracked crossing the 118 freeway near Simi Valley as many as nine times. Both of those animals eventually died after eating coyotes, and were found with the rat poison in their livers.

Biologists theorize lions and other critters can cross the 101 at Liberty Canyon, where an underpass links wilderness areas on both sides of the Ventura Freeway.

Of the four cubs born locally two years ago, only P-6 has avoided death at the paws of another cat. P-6 hunts for deer in the Malibu Creek State Park area and, like its father P-1, is wearing a GPS radio collar that can be detected by NPS researchers.

The poisons, brodifacoum and bromadiolone, are used in rat bait that accumulates in rodents, eventually causing internal bleeding and death.

“We don’t know how the anticoagulants are getting into the lions, because we know they are mostly eating deer, which makes up 95 percent of their diets, and there are no anticoagulants in deer,” Riley said.

“It’s possible that the lions occasionally eat a coyote that has been eating poisoned rodents, and we know that there are anecdotes of people using these anticoagulants to poison coyotes.”

Two lions who died near Simi Valley had large amounts of poison in their livers. “We know both of these lions had killed coyotes just before they died,” Riley said. “But no one had ever done a study to find out how much anticoagulant will kill a mountain lion.”

The rodent poison is widely sold at hardware stores and used by exterminators. Homeowners buy it because it makes rodents feel nauseous before they die, causing them to flee houses and die elsewhere. Although rodent poisons are not supposed to be used against coyotes directly, they are. In addition, rodents are a part of the coyote’s natural diet.

The joint federal-state mountain lion tracking program has run out of money, and scientists may have to cease tracking the mountain lions with radio collars.

“We’d really like to follow these animals as they range across the habitat, not only in the Santa Monica Mountains but also in the Santa Susanas, Simi Hills, and north on into the Los Padres National Forest,” said Riley.

CAPTION 1. Photo credit, NPS Photo
FIND—A previously unknown mountain lion is believed to be ranging in the Santa Monica Mountains. The new animal has not yet been given a P—for puma—designation.