Karen C. Drayer Wildlife Health Center

Survival and Sources of Mortality

Since the study began with the first collaring of a cougar in 2001, 30 GPS-collared cougars have died while circulating in the wild, all but 1 while still wearing GPS collars.  One additional individual was shot illegally but recovered. This figure represents 53.6% of the 56 radio-collared cougars monitored to the point of their death in the wild or being lost to monitoring due to collar drop off or malfunction, or other factors. The majority of deaths (63.3%) involved some sort of interactions with humans (car strikes, depredation permits, illegal shootings, legal shootings, and human-origin wildfires).

Causes of death for radio-collared cougars circulating in the wild were*:

Car strikes: 6 of 30 (20%)

Depredation permits: 6 of 30 (20%)

Disease confirmed or strong circumstantial evidence: 5 of 30 (16.7%)

Unknown: 4 of 30 (13.3%)

Illegal shootings: 4 of 30 (13.3%)

Fire: 2 of 30 (6.7%)

Unknown but evidence of trauma of unknown cause: 1 of 30 (3.3%)

Shootings deemed legal due to perceived threat: 1 of 30 (3.3%)

Intraspecific strife: 1 of 30 (3.3%)

The status of collared cougars whose collars dropped off or stopped transmitting prior to recapture, and captured kittens that were never recaptured for GPS-collaring, is unknown. Some of those previously captured and / or collared cougars whose status is unknown are also likely deceased given the mortality rates for collared cougars in the study.

Photo: Mountain lion hit by car