By JAMES GORMAN JULY 18, 2016

Excerpts from a New York Times article

 

Cougars can kill hundreds of deer over the course of their lives, leading some scientists to argue that restoring them to 19 states with large populations of deer could prevent automobile-deer collisions. Credit Konrad Wothe/Minden Pictures

What large mammal regularly kills humans in the Eastern United States?

And what other large mammal might significantly reduce those deaths?

The answer to the first question is the white-tailed deer. Deer do not set out to murder people, as far as anyone knows, but they do jump out in front of vehicles so often that they cause more than a million collisions a year, resulting in more than 200 deaths.

The answer to the second question, according to a new scientific study, is the cougar.

Laura R. Prugh, a wildlife scientist at the University of Washington; Sophie L. Gilbert, a wildlife ecologist at the University of Idaho; and several colleagues argue in the journal Conservation Letters that if eastern cougars returned to their historic range, they could prevent 155 human deaths and 21,400 human injuries, and save $2.3 billion, over the course of 30 years.

And although cougars do kill humans sometimes, the scientists estimated that number would be less than one a year, for a total of less than 30 lives lost, far less than the number of lives saved…

I have a personal interest in this new report. In 2004, I wrote an entirely selfish and completely undocumented essay lamenting the damage that deer were doing to my garden and suggesting, only partly tongue-in-cheek, that the lawn and garden community would be willing to sacrifice a few pets and joggers if mountain lions could be brought to the suburbs to get rid of the Bambi plague.

I noted that deer were also responsible for human deaths, although I confess that was not my true motivation.

I’m sure I wasn’t the first to have this idea. What deer do to cultivated suburban yards can make otherwise peaceful people quite bloody minded.

But I didn’t do the numbers.

Dr. Prugh and her colleagues have done the numbers in an attempt to find some real answers...

Then the scientists tested a variety of mathematical models and came up with their projections. One of the questions they needed to consider was whether the cougars would just be killing deer that would die anyway from starvation or illness…

But they were not able to get good estimates of pet loss, since it is hard to pin down which pets that disappear were killed by cougars. They may have been killed by coyotes, or cars, or have wandered off and been taken in by someone else.

Also, they could not account for the obvious emotional response to predators. Even if the estimate is correct that five times as many people would be saved by cougars as would be killed, death by deer and cougar are different.

“The idea of being killed in a car crash with a deer just doesn’t scare people the way the idea of a cougar leaping on your back in the woods does,” Dr. Prugh said.

But she hopes that if cougars do return to the Eastern states, an understanding that they could bring tangible benefits will make people “a little more accepting, even if they are still scared.”

See full article: http://www.nytimes.com/2016/07/19/science/too-many-deer-on-the-road-let-cougars-return-study-says.html?ribbon-ad-idx=7&rref=science&module=Ribbon&version=context®ion=Header&action= click&contentCollection=Science&pgtype=article