Whereas scientists are sadly accustomed to rangy mountain lions killed by vehicles after they try to cross roadways like the 101 Freeway in San Fernando Valley, this 12 months a cougar was killed by a illness removed from the freeways, a state company reported on Monday, Sept. 26.
P-65, a five-year-old grownup feminine, is the primary mountain lion in Southern California to perish from mange — a standard pores and skin illness attributable to a mite parasite — through the 20 years of U.S. Nationwide Park Service (NPS) analysis into native cougars. Scientists discovered her physique on March 4, 2022, close to a mountain stream within the central Santa Monica Mountains.
“All of those animals recovered from their mange illness, as finest as we may inform from distant digicam images or later examination,” mentioned Jeff Sikich, a wildlife biologist within the park, in a ready assertion. Sikich and different NPS biologists working within the 150,000-acre Santa Monica Mountains Nationwide Recreation Space have been unaware of P-65’s situation till after she died.
NPS biologists say the lion’s immune system was compromised by the consequences of rat poison which is commonly left exterior by householders or establishments reminiscent of colleges or native governments. Most probably, the lion ate a useless animal that had eaten a rat or squirrel that ingested the rat poison.
A necropsy discovered 5 “anticoagulant rodenticide” compounds in P-65’s liver: brodifacoum, bromadiolone, difethialone, chlorophacinone, and diphacinone. She additionally was uncovered to bromethalin, a neurotoxic rodenticide, the NPS reported.
Rodenticides journey up the meals net. Their deadly results have been related to inflicting immunodeficiency in bigger animals reminiscent of bobcats and mountain lions. That leaves massive cats extremely prone to contracting mange and dying from that usually non-fatal ailment, NPS scientists report.
Previously, scientists have efficiently handled mountain lions affected by mange by utilizing a topical anti-parasitic drugs.
Scientists decided P-65 was contaminated with mange as a result of an an infection attributable to mites of the genus Notoedres. A extreme case of notoedric mange causes onerous, crusty pores and skin, hair loss and open sores that may invite bacterial an infection and excessive lethargy, mentioned Winston Vickers, a veterinarian researcher at UC Davis who focuses on bobcats and mountain lions.
NPS researchers and different scientists say the presence of rat poison in P-65’s system prevented the lion from preventing off the illness, or it overworked her immune system to the purpose of failure.
NPS scientists first observed the connection between rat poison and mange in bobcats within the early 2000s. The collared bobcat inhabitants within the Simi Hills, Thousand Oaks, Agoura Hills and Oak Park dropped by 50% between 2003 and 2006. Necropsies discovered that 92% of the useless bobcats analyzed examined constructive for rodenticides.
Ten years in the past, U.S. Geological Survey scientists collared two bobcats in the Whittier-Puente Hills. The wholesome couple started to falter. First the feminine, WIN, died of extreme mange and her associate, ZEK, contracted it a short while later. The scientists captured ZEK, handled him at an Orange County veterinarian workplace, and released him back into the wild where he thrived, the company reported.
Within the early 2000s, the connection to rodenticides was established in such over-the-counter merchandise as d-CON, which contained the energetic substances brodifacoum, bromadiolone or difethialone. Scientists imagine the poison additionally might have killed birds of prey reminiscent of owls and hawks that eat rodents that ingested poison, and that it weakened bigger mammals because it intensified larger up the meals chain, harming foxes, coyotes, bobcats and mountain lions.
Josh Rosenau, conservation advocate with the Sacramento-based Mountain Lion Basis, mentioned mountain lions within the Santa Monica Mountains are hemmed in by roads and freeways and die in deadly collisions with automobiles. However the isolation additionally forces lions to eat smaller mammals that reside nearer to buildings and rat poison, particularly when deer, a most popular mountain lion meals, will not be current.
“The choices for foraging get restricted. So that they eat issues not most popular, like rodents, rabbits and raccoons,” Rosenau mentioned. “That restriction will increase the chance.”
Vickers, who research mountain lions in Riverside, Orange and San Diego counties, mentioned there are far fewer circumstances of mange within the Los Angeles space inhabitants. He theorized that the Santa Monica Mountain space lions might have a genetic defect that makes them vulnerable to mange.
He solely remembered one mountain lion with a extreme case of vary within the southern and inland ranges, and it needed to be put down. He says mange could be very treatable.
In reality, probably the most well-known mountain lion in Los Angeles, P-22, who roams the hills of Griffith Park and was on the duvet of the December 2013 difficulty of Nationwide Geographic with a backdrop of the Hollywood Signal, was successfully treated for mange in 2014. Like P-65, checks revealed diphacinone and chlorophacinone in P-22’s blood.
Within the NPS examine in collaboration with UCLA, of 140 bobcats, coyotes and mountain lions evaluated, 88% examined constructive for a number of anti-coagulant compounds. An anti-coagulant thins an animal’s blood and may result in the animal bleeding to demise internally, NPS scientists reported.
A wildlife overpass is being constructed over the 101 Freeway in Agoura Hills so animals can transfer from one space to the subsequent safely. Satirically, P-65 was the second feminine puma to cross the 101 in NPS’s examine historical past, when she traveled from the Liberty Canyon space the place the overpass is being constructed into the Simi Hills. She really darted throughout the roadway a second time, returning to the central Santa Monica Mountains.
She had three kittens in the summertime of 2020, P-88, P-89 and P-90. The latter two have been captured and acquired radio collars and each had mange, have been handled and recovered. However P-89 and P-90 have been killed on native roads: P-89 died on the 101 Freeway in Woodland Hills in July 2022 and P-90 died a number of weeks in the past on Freeway 33 in Ventura County, the NPS reported.