Cougars Recolonizing Historic Range Face New Human Threats

The reintroduction of cougars to their historic homeland is proving to be a challenge for wildlife managers in these areas, a new study reports, citing high numbers of human-caused deaths of cougars in reintroduction areas in South Dakota.

Cougars (Puma concolor) are slowly recolonizing parts of their historic range across the US Midwest, including the Black Hills region of South Dakota, according to a new report in the Wildlife Society Bulletin.

This population of cougars is separated from the nearest breeding population of cougars by a vast prairie, and cougar hunting is illegal in the region, but the big cats still face a number of threats, including human interaction.

Human development of the rural land, including networks of highways and new suburban business and residential districts, is taking a toll on reintroduced wildlife, the report says.

Despite protection from hunting, nearly 62 percent of cougar deaths in the 13-year study were attributed to humans.

The main cause of death in these cougar populations were vehicular collisions and lethal removal by a state agency due to human safety or depredation concerns, a find that runs counter to previous work that identified natural causes as the main source of mortality for the region's cougars.

The study authors documented 12 moralities among 31 cougars tagged for study between 1999 and 2005. An additional 85 untagged cougar moralities were analyzed during the course of the research, with vehicle collision being the main cause of death.

"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," said lead study author David Thompson from South Dakota State University. "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."