Humans responsible for 62% of cougar deaths in re-established populations

The reintroduction of mountain lions across the mid-western United States has made species management an urgent area of research for conservationists. A report in the Wildlife Society Bulletin explores the fatal cost of human interaction with cougars and asks what state agencies can do to protect both species.

Cougars (Puma concolor) are slowly recolonizing their historic habitats, including the Black Hills of South Dakota, but since they've been away, the land has become crossed with roads and home to many human communities.

"The cougar population in the Black Hills Region is unique, as it is separated by 180 km of prairie and agricultural land from the nearest breeding population," said Dr. David Thompson from South Dakota State University. "Yet, it is a viable population, which is safe from hunting and it has increased in recent decades through natural immigration."

The authors studied 31 cougars, captured between 1999 and 2005. Over the course of 1,570 days, 12 mortalities were recorded. Despite being protected from hunting nearly 62% of cougar deaths were attributed to human influences.

A further 85 dead cougars were analyzed during the study, with collisions being the most common cause of death. Snaring and illegal hunting were also identified as causes.

"Our work evaluated the types of mortality that occur in a naturally re-established cougar population on the eastern edge of the current range of the species in North America," concluded Thompson. "Our findings will be valuable to areas experiencing re-colonization of the species as well as providing insight into regions where human populations overlap with cougars from a management perspective."