Mortality in Wildlife: More than meets the eye

“It died of natural causes” and “there’s not a mark on them.”  These are common statements when government staff or the public find dead wildlife.  But what many people don’t realize is that thick coats hide body condition, as well as the evidence of injuries or illness.  Two recent wild animal mortalities in BC showed no obvious external abnormalities, but autopsy with examination of the internal organs told a different story.

The first case was described as a “sleeping caribou”.  An adult female caribou was found curled up beside a tree, head turned into her shoulder as if she was sleeping.  Her necropsy revealed severe emaciation with abnormal tooth wear, evidence of poor circulation, and a tiny degenerating fetus.  These are physical changes that took time to occur, and may reflect inadequate access to food and underlying health conditions.

The second case was an adult female mountain goat found at the bottom of a cliff, seemingly also asleep.  When she was examined, a number of serious changes to her internal organs were present.  She was also very thin and had been sick for a long time.  There was an injury to her ribs and the muscles around them, possibly caused by a horn (gore wound) from another goat.  The wound and bone had become infected and the infection spread through her blood to her heart.  The infection settled onto the heart valves and heart muscle and then spread into her lungs. The heart and lung infections likely led to her death.

These cases illustrate why it is important for wildlife mortalities to be examined by a wildlife health professionals. Both of these animals told very interesting stories that would have been missed had the members of the public who found them not made the effort to help BC Wildlife staff tell their stories.