female mountain lion f312

The Passing of F312

Our California Carnivore Project (formerly California Mountain Lion Project) team has some sad news to share: F312, a female GPS collared mountain lion that was nicknamed "Uno" by southern California photographers, died last night after being struck by a vehicle. Valiant efforts to save her life were undertaken by local veterinarian Dr. Scott Weldy, our biologist Lina Vu, Orange County Animal Care officers, and local residents, with California Department of Fish and Wildlife personnel also en route to help, but she succumbed to massive head and chest injuries before significant treatment could be started.

F312 female california mountain lion

She was crossing Santiago Canyon Road, a highway in Orange County that she has crossed successfully many times, but she failed to get across safely on this occasion. She succumbed to the most common cause of death for local mountain lions in our area - being killed while crossing roads and highways, something that any local mountain lion has to do many times in a lifetime due to their large territories and the number of busy streets and roads in our area.

The story behind the nickname

F312/Uno was given her nickname by local photographers due to an old injury to her right eye making her two eyes look different in photos. She became famous locally because of how often she got photographed on trail and remote cameras put out by local residents, OC Parks, or our team. Since it was clear who she was in the photos she was easily identified as a specific known individual - an unusual thing with mountain lions due to their similar looks from one to the other.

A cool cat

She also was somewhat famous for her seeming laissez-faire demeanor around people at times - often paying little attention to hikers or others she might encounter. On one occasion she walked right past the admission booth at one of the local wilderness parks without even a side glance (she didn't have to pay).

F312's contributions to mountain lion research

F312 was captured in early January 2021 as a young adult just over 2 years old as part of the long-running UC Davis mountain lion study in southern California. A GPS collar was fitted, various samples were taken, and she was released where she was captured, the standard approach to mountain lion research. GPS collars and samples taken at capture allow researchers such as our team and others to better understand the health of the animals and where the animals travel so that we can advise highway agencies where improvements need to be made for safe wildlife crossing - something that also benefits driver and passenger safety. Fencing projects that our team has helped design in the area have dramatically reduced mountain lion and other wildlife deaths on the roads, but as this shows us these improvements are needed in many more places. 

F312 taught us a lot in the two short years we knew and followed her life path. We knew from her collar data and cameras when she was hanging out with a male and likely breeding, and when to expect her to possibly den. We suspected denning on more than one occasion, but she only emerged onto the trails with kittens once (it is not uncommon for young females to not produce kittens successfully each time they breed). On the one occasion when she did have kittens emerge with her, there were FOUR of them! The family thrilled local photographers when they were lucky enough to catch them on camera.

california mountain lion f312 and her cubs
Photo Credit: Collin Eckert

Unfortunately, none of the four kittens survived to the age when they would leave their mother, with two also killed by cars - one on Santiago Canyon Road near where F312 was killed and one on Glenn Ranch Road. Disease claimed one of the kittens and one simply disappeared while still quite young.

F312 also taught us a lot about the effects of development patterns in the foothills of Orange County and the way that clusters of housing that extend up the ridges force animals like mountain lions to weave in and out of the remaining patches of forest and canyon as they attempt to find adequate food. These development pattern place the animals in closer proximity to people than would normally be the case, but fortunately mountain lions like F312/Uno have little interest in us most of the time. Disturbance by humans does have a negative effect on their ability to live their lives as they should however. The fact that individuals like Uno can find a way to do so despite the ubiquitous human presence is a testament to their versatility.

Everyone on our UC Davis team, and many many members of the community, are saddened to part ways with F312/Uno. This event reminds us of how much more work we all have to do with the highway agencies to erect protective fencing and safe crossing structures for all the wild animals, not just mountain lions. Thank you, F312, for teaching us so much.

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