Cougars Feed Prey in the Forest

Persecuted for centuries as pests or worse, beasts dangerously inimical to man, the role of cougars in healthy ecosystems is finally being understood by science.  This long overdue development may lead to their being spared humanity's current unwillingness to live in harmony with Nature. Pumas (Puma concolor) are thought to be still declining in number according to Panthera, the conservation group, but at least they are no longer widely exterminated by bounty hunters, frightened farmers, or government agents in the United States.  Mountain lions are loosing habitat at an alarming rate, so their future is uncertain.

A recent study by Panthera near Yellowstone NP adds to our knowledge of the predator's positive role in ecosystem health. Cougars are known to hunt in favored areas that suit their stalk and ambush style.  A dozen mountain lions could produce 220,000 pounds of carrion scattered about the landscape. The rotting flesh provides nutrients to the soil, which in turn promotes the growth of nitrogen-rich plants that herbivores need to survive.  This nutrient cycling is a positive feedback loop that benefits both prey species and the big cats. [graph credit, Billings Gazette.] The study was published in the journal, Landscape Biology.  

Lions studied were fitted with location collars.  Between 2014 and 2018, 174 kill sites were found.  An average kill rate for the 50 lions was 54 ungulates per cat, which created 482 nutrient "hotspots" over an average lifespan of nine years.  Pumas tend to eat only about a third of the animal they kill, leaving the rest for carnivores lower down on the food chain. The scientists could assess how much decomposing flesh at the kill site added nutrients by analyzing soil samples.

Cougars have exceptional hunting skills and they tend to hunt in the same areas over time.  Females in Yellowstone Park kill once a week while males often kill larger species every 11 to 13 days. These hunting grounds are therefore "fertilized" in somewhat the same way human hunters plant crops to attract desired prey. [see graph above] There is no recognizable intention involved in the nutrient cycle in which the catamounts play a crucial role, but like everything else in Nature, the cycle works to support life on Earth.