Hollywood Hills mountain lion captured on film
4 December 2013 Last updated at 07:06 GMT
Los Angeles is known for its sprawling urban landscape and wide freeways of concrete and tarmac, but not necessarily for its wildlife.
But on the edge of downtown LA is one of the biggest urban parks in America - surrounding the Hollywood sign - and in that park, scientists have found a mountain lion.
Alastair Leithead reports.
Photo by Steve Winter/National Geographic