Have you ever wondered what P22, located in Griffith Park, is eating? This is understandably a common question since he is a large carnivore living in a small park within the heart of urban Los Angeles. In fact, he is more urban than any other mountain lion known to exist. Local residents are only accustomed to sharing their backyards with smaller predators that don’t get any larger than coyotes. However, mountain lions are relatively new members of the Griffith Park wildlife community and local residents and carnivore biologists are equally curious about what prey species he’s ambushing in Griffith Park. I went on a gruesome scavenger hunt to figure out what he has been eating recently. I am excited to now share a glimpse of what L.A.’s favorite mountain lion is dining on.

A Little Background

Like all cats, mountain lions are strictly carnivorous (only eat meat), and locally, prefer deer to sustain their large bodies. Their diet is one reason they are less adaptable to urbanization than a carnivore that is both smaller and omnivorous (eats plants and meat and so has more options in urban areas), like a raccoon. Based on what we know from kill-site analyses conducted locally by the National Park Service (NPS) in the Santa Monica Mountains over the past decade, we know that local mountain lions are specializing on deer but do opportunistically pick off the occasional small prey item (e.g., coyote, raccoon). To date, NPS has visited a few of P22’s kill-sites and have only found deer kills, which is a testament to the health of the Griffith Park deer population.

Mountain lions will cache large prey like deer, and often feed on it for several days. They may drag it a few meters from the location of the kill and to cache it, cover it with dirt and leaf litter. They will return to the site of a kill for multiple nights and repeatedly hide it until they finish feeding on the prey. During the day, they find a daytime resting location (day bed) not too far away from the kill site (generally at least several hundred meters away from the cache site). If they kill a smaller prey species such as a rabbit or raccoon, they will usually consume all of it at once instead of caching the prey.

Biologists use the GPS collar information to identify potential kill sites. Presently, biologists are able to access real-time GPS collar data through a website that remotely accesses collar data for each collared mountain lion. The collars regularly send the data to the website via satellites or cell-phone tower transmission, like sending an email via a smartphone.

Once biologists have the data, they look for GPS locations where the mountain lion has remained for multiple hours (more than 4) or returned on multiple consecutive nights. However, even with pretty accurate GPS information it is not as simple to find these locations as it seems. The kills are never directly on human social trails. So, some obstacles that often make finding the kill difficult include poison oak, a pack of coyotes having the carcass away in multiple directions, thick vegetation, and especially difficult terrain.

Finding a Carcass in a Haystack

This past weekend, Laurel and I went out with a GPS and a few maps of potential kills made this past month. We strategically parked in a location that was close to most of the kill sites. We usually are able to hike to within 10 meters of the location, at which point we need to just walk around and not only look for bones or a buried carcass but also use our noses to narrow down the location. Although, you never know exactly what the carcass is going to look like or exactly where it will be hidden, you can usually count on smelling the relatively fresh kills. I definitely smelled all 4 of the kill-sites before we found them. The carcasses were either found in deep ravines or on steep hillsides that required a great deal of bushwhacking mostly through poison oak.

Wildlife CSI

Once we found the kill sites, we recorded data including the date we found the kill, the prey species, the exact kill location, sex of prey (when possible), and an age estimate of the prey if possible. For deer, we had a guide to age deer by their teeth shape, definition, and degree of wear.