Mountain lion P-55 found dead from unknown causes in Santa Monica Mountains

The remains of P-55, pictured above, were found recently in the Santa Monica Mountains. The male adult’s death is a mystery due to the body’s state of decomposition when it was found.
(National Park Service)

A mountain lion who won fame after he was photographed peering through the sliding glass door of a Westlake Village home has been found dead in the Santa Monica Mountains, the National Park Service announced Wednesday.

The decomposed remains of P-55, a 3-year-old adult male, were found in his home range in the northwestern end of the mountain range, officials said. The cause of death is unknown because his tracking collar failed to emit a “mortality signal” and his remains were too decomposed, said Park Service spokeswoman Kate Kuykendall.

“Possible causes of death to this seemingly healthy animal include rodenticide poisoning or perhaps a fight with another male, although there were no signs of a struggle,” she said in a statement.

P-55 gained local notoriety in February when a Westlake Village family photographed him trying to charge through their backyard sliding glass window to get to their pup.


After four attempts to get in, P-55 vanished into the night, KTLA reported.

Last summer, P-55 made the perilous journey twice across U.S. Highway 101, a crossing that has killed more than a dozen other mountain lions since 2003. Barriers posed by the 101 and other freeways have limited the genetic diversity of local mountain lions.

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