Cougars (Puma concolor) have not lived in Oklahoma, Missouri and other states around the Midwest since the beginning of the 20th century. Now the cats are returning to and repopulating some of their former Midwestern habitats, according to research published in June by the Journal of Wildlife Management.

Cougars once lived throughout most of the U.S. and Canada, but state-sponsored bounties put in place to protect livestock and humans from what were often deemed “undesirable predators” led to the cats' extermination in eastern North America and the Midwest. By the second half of the 20th century they were mostly restricted to states and provinces west of the Rocky Mountains.

Things started to turn around for the cougar in the 1960s and 1970s, when, one by one, states rescinded the bounties and made the animals a managed-game species. They have now been seen in Oklahoma, Missouri, Arkansas, Illinois and several other U.S. states and Canadian provinces in and around the Midwest, and the sightings are growing more frequent, according to the new paper.

The expansion has been driven by the cougars' solitary, territorial nature, explains the paper's lead author, Michelle LaRue, research fellow for the Polar Geospatial Center at the University of Minnesota. “When a female cougar has males, they have to disperse away from where they were born,” she says, which prevents the males from inbreeding with their female relatives and helps them to avoid conflicts with older, more powerful males. LaRue and her fellow researchers examined 178 confirmed Midwestern cougar sightings from 1990 to 2008. These included carcasses, as well as scat and tracks, along with camera and video evidence. The number of confirmed sightings during this period increased steadily each year, from two animals in 1990 to 34 in 2008. By comparison, the total population of cougars in North America is estimated at around 30,000 animals. Of the 56 carcasses, 76 percent were male, typical of the gender's role as the primary dispersers of the species.

LaRue says this trend is probably just the beginning of cougars recolonizing the Midwest. “Now we can start asking more questions: Where are they going to end up, how many are they going to be and how are they going to interact with their ecosystems?” LaRue and her co-authors suggest that wildlife professionals begin to think “about public awareness campaigns in areas likely to encounter dispersing cougars” because people in these Midwestern states are not used to living with large predators.

Adapted from the Extinction Countdown blog at blogs.ScientificAmerican.com/extinction-countdown

COMMENT AT ScientificAmerican.com/sep2012

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