Massive die off of deer newborns and female deer this winter, ‘catastrophic’ in Wyoming, USA
Last summer, Wyoming deer researcher Kevin Monteith and a handful of others wandered Wyoming’s southwest mountains in search of mule deer newborns.
They found 70 and placed on each animal a radio collar to monitor its survival. It was the second summer of what was supposed to be a three-year study that had shown, on average, a little more than a third of the fawns in the Wyoming Range Herd survive to their first birthdays.
This year, they all died.
As a winter harsher than locals had seen in decades raged across the western part of the state, Monteith and his team waited while a pilot recorded one radio signal after another showing the fawns with collars were dead.
Fawns die during harsh winters. They don’t carry the reserves adults store on their rumps and sides. They’re also smaller, requiring proportionally more energy to survive than their mothers, Monteith said. But rarely do almost 100 percent of the fawns die in a herd that numbers in the tens of thousands.
And worse, the does, the ones responsible for keeping herd numbers up and giving birth to one or two fawns a year, are also collapsing from exhaustion and starvation. Monteith estimates about 35 percent of the does have died, and more will likely follow.
“To date, I’ve handled more than 3,000 mule deer over many years and conditions, and I figured animals would be in bad shape, but I’ve never seen anything like this,” said Monteith, a professor at the University of Wyoming. “To see a whole segment of a population not have anything left is distressing and sad. Adult females are weighing like a bag of bones.”
The winter could be considered a crisis for a herd that draws hunters and wildlife viewers from across the country and even overseas. But for Wyoming biologists like Monteith, the die-off represented a unique opportunity rarely if ever afforded in wildlife research. Because research on deer in the Wyoming Range began a few years ago, the scientists will be able to answer several critical questions: What factors led to the die-off? What, if anything, can be done to bring them back? And could this, in the long run, actually benefit the herd?
“When things become severe enough that we see adult survival drop, you know things are bad,” Monteith said. “We have a once-in-a-lifetime or many lifetime opportunity to study the effects of a bad winter.”
Courtesy of trib.com