Mountain lion P-32 killed crossing Interstate 5 near Castaic

P-32 at a deer kill in February. National Park Service.

P-32, the only male cougar known to have dispersed from the Santa Monica Mountains by crossing the U.S. 101 freeway, was struck by a car and killed while trying to cross I-5 way up by Castaic. The National Park Service said he was apparently hit around dawn on Monday. P-32 is the 12th mountain lion killed on a freeway or road since the park service study of Santa Monica Mountains pumas began.

You know his photos if you have been following the Los Angeles area study of mountain lions. In 2013, we and everybody else ran a photo of P-32 as a kitten being tagged by park service scientist Seth Riley. Now Riley has to conduct a necropsy to learn what he can about P-32's travels. (See photos down below on this page.)

Just in April, P-32 was half of what seemed like a remarkable emerging story from the NPS study of the Santa Monica Mountains pumas. P-32 had followed his sister out of the Santa Monicas and across the 101 freeway into the Simi Hills. Earlier, the pair had been photographed at a deer kill with their mother, P-19. View on Facebook.

From today's NPS release:

Prior to being struck on Interstate 5, he had managed to cross the 101 Freeway, State Route 23, Highway 118 and Highway 126 (see map). What had been a textbook case of successful dispersal all the way from the Santa Monica Mountains into Los Padres National Forest took an unfortunate turn when he headed east and attempted to cross one additional freeway.

“This case illustrates the challenges that mountain lions in this region face, particularly males,” said Dr. Seth Riley, a wildlife ecologist with Santa Monica Mountains National Recreation Area. “P-32 conquered all kinds of freeways and highways to reach the Los Padres, but it was probably another dominant male that made him leave the area and attempt one last crossing, which obviously was not successful.”

Still considered a juvenile, P-32 was approximately 21 months old and had first been ear-tagged by the National Park Service at four weeks of age. Based on GPS data from the animal’s collar, he was likely hit by a vehicle between 4:00 and 6:00 a.m. Monday morning.

Since the study began in 2002, researchers are aware of only one male mountain lion born in the Santa Monica Mountains that has survived into adulthood, the famous Griffith Park mountain lion known as P-22. DNA evidence indicates he was born in the Santa Monica Mountains and thus had to cross both the 405 and 101 Freeways to make it to Griffith Park. Though he was able to flee the territory of more dominant adult males, his dispersal is not considered successful because he is now isolated in a small patch of habitat with no reproduction opportunities.

P-32 managed to travel a long way from home before being struck. The NPS blog has some more discussion and a map of P-32's travels, plus the fact that he was in competition with another cougar in his travels.

But why he may have crossed leads us to the other challenge: intra-specific conflict. Mountain lions need ranges of 75 to 200 square miles, with the males taking areas on the higher end. Males try to overlap with as many females as possible and don't tolerate competition from other males. (And in what appears to be an unusual case, P-1 did not share well, even with females. He killed two of his offspring and the mother of those kittens, among other mountain lions.)

So it makes sense that P-32, still a juvenile at about 21 months old, was likely trying to avoid other males and eventually establish his own range. Getting across the 101 was the first challenge in that effort. It was not, however, the last.

Once past Highway 118 and the rolling Simi Hills, our GPS tracking shows another male mountain lion, P-38, was hot on P-32's tracks. Though it's impossible to determine intent based solely on GPS data, P-38 appeared to be closely following the younger animal through the Santa Susana Mountains until P-32 crossed Highway 126 in the Santa Clara River Valley.

Free at last? Not so fast for P-32. We believe another mountain lion may have pushed him out (It was possibly the very large P-16, who also dispersed north of the 126 into Los Padres National Forest before researchers ultimately removed his GPS collar). And it was in that, possibly still searching for a home range, that he met his fate attempting to cross another busy freeway.

Seth Riley and another Park Service staffer prepare P-32 for necropsy.

Riley with P-32 as a kitten in 2013, in the Santa Monica Mountains above Malibu.

Edited and updated after posting