A cougar takes a load off. Photo:
Mountain lion, puma, panther, painter, catamount, or cougar. All of these names describe North America鈥檚 largest feline predator. Inhabiting the remote lands of the western United States, shows that cougars are spreading eastward, back into areas from which they were extirpated a century ago.
The , a non-profit that monitors cougar populations, collected records of the big felines outside of their modern western range from 1990 until 2008. Records included verified sightings, tracks, DNA evidence, cougar carcasses, or livestock depredation. Researchers from the University of Minnesota analyzed these data to see if cougars were moving eastward.
They found 178 records of cougars in the Midwest, indicating that the cougar population in the region is increasing. Additionally, the number of cougars increased steadily over time during the 18 years of data. Three established breeding populations of cougars now exist in the Black Hills, the North Dakota Badlands, and in western Nebraska.
Confirmed cougar locations from 1990鈥2008. Dark-green areas represent the population in western United States and established cougar populations in the Black Hills, South Dakota, the Badlands, North Dakota, and northwestern Nebraska. Photo: Michelle LaRue /
Cougars used to span from the Atlantic to the Pacific, and from British Columbia to Southern Chile. 鈥淭hey were one of the most widespread land mammals in the western hemisphere,鈥 says Michelle LaRue, an ecologist at the University of Minnesota who lead the recent research.
Starting in the early 1900s, however, cougar populations declined in eastern and central North America due to hunting and a lack of prey. In March of 2011, the U.S. Fish and Wildlife Service officially declared the eastern subspecies , although it had likely disappeared as early as the 1930s. Another subspecies is found in the Florida, where it is commonly called the Florida panther. With less than 200 individuals remaining, the Florida panther is highly endangered.
Western cougar populations have increased since the 1960s and 70s, and now their dispersal may establish permanent populations in the Midwest. Typically it is the male cougars that disperse, moving out of the area where they were born in search of a new territory. Some cougar data in the study came from carcasses, and 76 percent of these carcasses were male, suggesting that male dispersal is driving the eastern movement of the population.
LaRue鈥檚 research also showed that 62 percent of cougar confirmations in the Midwest were within approximately 20 kilometers of suitable cougar habitat. LaRue says that cougars need rugged terrain and thick forest cover away from both people and roads. 鈥淭hey are stalk and ambush predators," she says, "so they need cover in order to hunt.鈥 Despite agricultural development in the region, cougar habitat does exist, raising the possibility that cougars can persist long-term.
Unsuitable habitat does not hinder cougar movement, because they will readily travel through it to search for a new territory. A year ago, for example, a cougar from the Black Hills, South Dakota, traveled through Minnesota, Wisconsin, and New York before being by a car in Milford, Connecticut.
The Connecticut cougar traveled much farther than the cats in LaRue鈥檚 research, and it is not likely that New England will see a sudden influx of cougars anytime soon. But LaRue鈥檚 results confirm that these massive cats are on the move, and it is time to start planning for their expansion out of the west.
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