Karen C. Drayer Wildlife Health Center

A camera trap on Orange County Parks land caught the interaction of two of our study's radio-collared mountain lions, male M96 and female F62, in interesting behavior consistent with some portion of the breeding phase. Mountain lions are solitary animals and adult males and females are normally only found together in the 3 - 10 day period when they are breeding. F62 was captured as a kitten 4 years ago and the project has monitored her progression from kitten to dispersing juvenile to adult with an established territory. M96 is a more recent capture and is estimated to be 5 years old. The project has also been able to follow his territorial range.
In this sequence, caught by luck in front of one of the trail cameras maintained by our collaborators at Orange County Parks, F62 is the one with the red ear tag in her right ear that is more active, moving over and around M96 (he has a yellow ear tag in his left ear). Interpretation of what she is trying to tell him is up to the imagination, but one suspects that there is a slight difference between the two as to interest in breeding at that particular moment.  If breeding activity was successful in this case, we would expect kittens to potentially be in F62's future approximately 90 days from her being impregnated. This means that we will be hopeful that F62 will appear on our field cameras this fall with kittens in tow. 
Many thanks to Allan McGee and Orange County Parks for allowing us to usethese photos.

Mountain Lion and Bobcat Project

The Karen C. Drayer Wildlife Health Center has been working on mountain lions in Southern California since 2001. Since that time our focus has been

We have placed GPS collars (and one VHS) on 65 lions to date. The collars allow us to track the movements and behavior of the felines in order to document their habitat use. They also help us determine likely sites to be able to trap them. Using cage traps with roadkilled deer for bait, we sedate the cats, take blood, DNA and feces samples to determine health, check or apply collars.

The project has had great success trapping lions with cage traps, a process which is far less likely to result in injury to lions than either snares or dogs, which continue to be the more prevalent capture methods.

Update, September 2012

  • Total individuals captured since 2001 = 72
  • Total number of captures or recaptures = 128
  • Total individuals GPS collared = 65 (some captured individuals were sampled but were too young for collars at the time and were not recaptured later)
  • Total known mortalities of GPS collared individuals = 34 (52%)
  • #1 cause of death = vehicle strikes, followed by depredation permits, illegal shootings, disease, and fire - all told about 2/3 of deaths were directly related to humans
  • Additional animals sampled for DNA (most of these were uncollared animals that were hit by cars or killed on depredation permits) = 25 - 30 (have to check some other records on my computer to know this number for sure but hard drive down at the moment)
  • We have sampled right around 100 total animals for DNA plus some fetuses of females that have died (in order to better ascertain the parentage patterns in the population).

Update, July 2012

One of the mountain lions the WHC has been tracking hourly since February, M91, was killed on the 241 Toll Road near its junction with the 91 Freeway in Orange County early in the morning on July 7, 2012. M91 was a young male of dispersal age (between 1 ½ and 2 years old) that was captured originally with his mother (F89), brother (M93), and sister (F92) on lands that are part of the Irvine Ranch Natural Landmarks lands near the Coal Canyon corridor to the Chino Hills State Park. M91’s brother, M93, was with M91 when he was struck by the vehicle, but so far there is no evidence that M93 was injured (his collar data shows that he is still moving across the landscape in a normal fashion).

The WHC study has been looking at the link between roads and mountain lion mortality in this area since 2006, and has documented over 75 crossings of the 241 Toll Road by GPS-collared mountain lions in that time, with 3 crossings that were unsuccessful (fatal to the lions). Numerous un-collared mountain lions have also been documented as being killed on the Toll Road during that time, along with several hundred (combined) deer, coyotes, and bobcats. In the Santa Ana mountain range as a whole (from Irvine south to Fallbrook), more than 20 mountain lions have been documented as having died on roads in the last 10 years, a concern in a population estimated to only number 20 to 30 adults at any given time.

Vehicle collisions have been the number one cause of death for GPS-collared mountain lions throughout our Southern California study area. Tragically, M91 was just over a kilometer away from a safe bridge crossing, and even closer to some suitable culverts that a mountain lion could use to cross safely. Our research as well as research in other areas suggests that proper fencing is the primary way to prevent wildlife collisions with vehicles and to funnel mountain lions, deer, and other wildlife to safe road crossings. The Orange County Transportation Corridor Agency, the Nature Reserve of Orange County, and others are supporting our research to help identify locations where fence improvements are most needed on this and other highways, and what those improvements should be, in order to reduce the impact of area roads on wildlife. We are hopeful that needless deaths like M91’s can be prevented in the future if recommended improvements occur.

Update, April 2012

Current totals this field season - 12 animals captured 15 times; 11 animals are new to the study.

Total number of cougars collared since study began = 64. Bobcats captured = 12. Additional animals have been captured that were not collared due to being too young at the time of capture. Over 120 total cougar captures during the entire study period and 15 bobcat captures.

Below: Footage of mountain lion F89 and her three nearly full-grown kittens checking out traps in early April 2012. All four lions were caught, examined, collared, and safely released.