February 27, 2013
Ready or not, mountain lions are headed back to the Midwest.
More than a century after they were eradicated in the middle portion of the United States, and about 40 years after states began recognizing them as a game species rather than a nuisance animal, mountain lion numbers are growing in areas outside of the West, their typical U.S. stronghold.
"The question now is how the public will respond after living without large carnivores for a century," said Michelle LaRue, a research fellow for the Polar Geospatial Center at the University of Minnesota. "We believe public awareness campaigns and conservation strategies are required across these states."
Due to hunting, lack of prey and decreased habitat, the population of the mountain lion, or cougar, declined dramatically after 1900, leaving the remaining big cats isolated almost exclusively to areas west of the Rockies.
More than a century later, mountain lions are back and have spread across 14 states and the Canadian provinces of Ontario and Manitoba.
While saying the popularity of trail cams placed by hunters in the woods has likely increased the number of cougar sightings, LaRue said the territorial and wandering nature of the species has helped in the population increase in the Midwest.
“Mountain lions are very territorial, specifically adult males,” LaRue said. “When adult males don’t have an area that where they feel comfortable or where there isn’t already a dominant male, they will strike out on their own.”
One such male traveled about 1,800 miles from South Dakota to Connecticut before being struck and killed by an SUV.
Most of the mountain lions that seek new territory are young males between 1 1/2 and 2 ½ years old, because in established populations the dominant male will kill them if they stay.
“As the available territory become no longer vacant, the young male cougars have to go elsewhere,” LaRue said. “That’s what we think is happening. There are no more pockets of vacant habitat or territories left in the west. They’re forced to go elsewhere, and elsewhere happens to be the Midwest -- where there’s habitat but no competing cougars.”
All they need to travel great distances, LaRue said, is habitat with enough prey to sustain them. In addition to forest cover and rugged train, they also need dispersal corridors (typically rivers) that allow for easy migration.
“They’re a stalk-and-ambush predator, so they need places to hide,” LaRue said.
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 the east and Midwest. By the 20th century they were mostly restricted to states and provinces west of the Rockies.
“In the 1960s, cougars were switched (by states) from bountied animals to game species, which probably led to a resurgence in the West,” LaRue said. “And as the populations grew in places like the Black Hills of South Dakota, the Badlands of North Dakota and northwestern Nebraska, more adult males were forced to seek out new habitat.”
Breeding populations were established in the Black Hills in the 1990s, the Badlands and northwestern Nebraska in the following decade. The animals appear to have continued their eastward spread from those locations. They have now been seen in Oklahoma, Missouri, Arkansas, Illinois and several other Midwest states and Canadian provinces, and the sightings are growing more frequent,
Just since the middle of December, there have been five new mountain lion sightings in Missouri, according to The Cougar Network, a nonprofit monitoring group.
Cougars are classified as game species in most states and a “specially protected mammal” in California. Mountain lions are protected by law, but most states allow persons to protect themselves and their property if threatened.
Today, regulated mountain lion hunting seasons are held in 10 states – Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming – as well as two Canadian provinces, Alberta and British Columbia.
Working alongside scientists from The Cougar Network and Southern Illinois University in Carbondale, LaRue and principal investigator Clay Nielsen analyzed cougar sightings reported since 1990.
Their study covered more than 2 million square miles of territory. In addition to confirmed sightings, they looked at carcasses, tracks, photos, video, DNA evidence and cases of attacks on livestock. Only sightings verified by wildlife professionals were included.
The results, published in The Journal of Wildlife Management, reveal 178 confirmations of mountain lions in the Midwest, with the number increasing steadily between 1990 and 2008. These included carcasses (animals killed by cars, trains or hunters) as well as scat and tracks, along with camera and video evidence.
“The recolonization of former range by cougars is one of the most significant changes in the wildlife landscape of the U.S. in the last few decades,” Howard Quigley, the director of the Teton Cougar Project and the executive director of the jaguar programs for Panthera, told Scientific American. “One key to the future – and to the successful colonization – will be the presence of enough good habitat to support resident cougars.”
LaRue said as the mountain lions move eastward, questions remain – mostly to be determined how they will coexist with humans.
“Now we can start asking more questions,” she said. “Where are they going to end up? How many are they going to be? And how are they going to interact with their ecosystems?”