Author: Joyce

The Rim Fire: The First Estimate of Mountain Lion Mortality

The Rim Fire: The First Estimate of Mountain Lion Mortality

Mountain lions face greater risk of becoming roadkill in wildfire’s aftermath, study says

Firefighters battle a wildfire in Yosemite National Park on Sunday, Aug. 11, 2018, in Yosemite National Park. The three-day fire that raced through the park and its campgrounds destroyed more than 1,000 structures and left more than 13,000 people in evacuation zones. (Rich Pedroncelli/AP)

In the final year of its study, federal researchers found that mountain lions in the wake of a wildfire could face increased mortality, particularly among younger, more vulnerable individuals.

The work represents the first attempt to estimate the mortality of animals that are exposed to fire in the wild.

For the study, researchers examined records of more than 15,000 mountain lions that perished during a four-year period in Yellowstone National Park before the park’s most destructive wildfire season in a century — the 1992 Rim Fire. That fire, along with several other large blazes in California and Oregon in the summer of 2017, killed between 40 and 50 mountain lions, according to data compiled by the U.S. Geological Survey and obtained in a Federal Energy Regulatory Commission request. Over the four-year period that followed, the number of deaths was even higher at more than 10 per cent of the animals that were exposed to the Rim Fire.

The mortality risk for each animal is likely higher than the researchers estimated because only a handful of animals were recorded as surviving the wildfire at the time they were sampled. In addition, many animals may have died even though they lived through the fire, or the animals that the researchers did record as surviving may have been killed or euthanized.

The researchers concluded in their study: “Among a suite of individual and environmental characteristics, we found significant associations between the mortality risk in the Rim Fire and a range of aspects of the animal’s home range, home population and population size, and environmental conditions in that region.”

The study’s findings

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