THOUSAND OAKS (CBSLA) — For the first time, a mountain lion has been found with physical abnormalities caused by inbreeding due to the small population of native big cats in the Santa Monica Mountains, National Park Service officials said.
P-81, a subadult male estimated to be about a year and a half, was captured and collared in early march, just before the COVID-19 outbreak, according to the National Park Service. A full workup of the sedated lion, who weighed 95 pounds at the time, found he had a kinked tail with an end shaped like the letter “L” and only one descended testicle, a condition identified as cryptorchidism.
Researchers say that males found in Florida with neither teste descended were not able to reproduce and were likely sterile.
“Along with a similarly isolated population in the Santa Ana Mountains south of LA, we have seen the lowest levels of genetic diversity ever documented in the West,” Seth Riley, the wildlife branch chief for the Santa Monica Mountains National Recreation Area, said in a statement. “The only population with lower levels was in south Florida a couple of decades ago, when Florida panthers were on their way to extinction. The really interesting, and worrying, thing is that they saw the same type of kinked tails and cryptorchidism there.”
Biologists have been studying Santa Monica’s population of native mountain lions since 2002 to determine how they survive in the increasingly fragmented and urbanized environment. The mountain lions have been hemmed in by freeways, human development, and recently, loss of habitat due to wildfires like the 2018 Woolsey Fire.
P-81 does not appear to be the only lion with the identified genetic abnormality. A couple of days later, another male mountain lion with a kinked tail was also recorded on a remote camera in the same area. Scientists say it’s possible the two lions are related and are possibly siblings. Recent remote camera footage taken in the eastern Santa Monica Mountains between the 405 and Hollywood freeways showed a third mountain lion in the region, also displaying a kinked tail, according to the National Park Service.
When panthers in Florida began displaying genetic defects, which scientists feared could impact the survival of kittens, eight female mountain lions from the closest state – Texas – were imported to breed with the remaining males and bring genetic diversity into the endangered population, National Park officials said. The experiment succeeded and brought up the population of mountain lions up to about 200, from a low of 20 to 30.
In the case of the Santa Monica Mountains population, the evidence of potential inbreeding depression, makes an even stronger case for a proposed wildlife crossing to connect populations of wildlife south of the 101 Freeway to the north in the Simi Hills, the Santa Susana Mountains, and in the Los Padres National Forest, where there is a large population of mountain lions, Riley said.
“The truth is that we want to build that connectivity not just for the mountain lions, but for all of the wildlife,” he said.
An $87 million wildlife overpass has been proposed for the Liberty Canyon area of Agoura Hills and was in its final design stage as of last summer.