OUT: Winter Counts December 17, 2008
Biologists rack up frequent-flyer miles in annual big-game count
As western Colorado readies itself for another winter storm, Division of Wildlife biologists are up in the air about elk and deer.
It’s that time of year when biologists start logging air time in helicopters and light airplanes to determine sex and age ratios in elk and deer herds, information that contributes to herd management plans, including future hunting seasons.
The flights don’t count every elk and deer but they do give biologists an idea of how well herds are faring.
Flights are done early in the winter for a couple of reasons. Bull elk and buck deer haven’t dropped their antlers, which makes differentiating sexes easier, plus deer herds still have the males mingling with the females.
Buck deer generally drop their antlers in early January with bull elk dropping theirs roughly a month later.
Elk herds have split up, with cow, calves and young spike elk hanging together while bulls head elsewhere. That makes bulls more difficult to find and count, but in recent years the DOW has developed new methods to make sure elk counts aren’t biased toward cows and calves.
When the flights encounter elk or deer, the biologists take note of how many males and females are seen as well as how many females and young animals.
These numbers, plus survival rate information, are entered into a population model that gives an estimate of population makeup.
“Those numbers, along with harvest data from hunters, are the real key pieces that go into our population models,” said Rick Kahn, the DOW’s terrestrial section manager.
Kahn said local knowledge of where herds winter gives biologists an idea of where to look to find wintering animals.
Biologists are particularly interested in herd numbers this year since it comes on the heels of one of the hardest winters in a decade or more.
Emergency feeding programs in the Gunnison Basin and around Eagle were undertaken last winter to relieve the burden of record-level snows.
Mother Nature, however, had the better hand and this fall hunters and ranchers have been telling the Division that last winter killed more animals than suspected.
The suspicions are based on not seeing animals during hunting season and by ranchers not having as many animals as usual in their fields.
But anecdotal evidence, while informative since it often comes from people with several decades or more of experience, isn’t enough by itself.
That’s why the winter overflights, which began last week in the Northwest Region and will continue across the Western Slope for the next two or three months, are so valuable.
“We’ve heard a lot that people are not seeing (elk and deer) where they expected to see them,” said Bill DeVergie, DOW area wildlife manager in Meeker. “There have been a number
of complaints from hunters that the deer just not here, that they ‘had to have died.’ ”
DeVergie and other DOW officials don’t dismiss the complaints off-hand but, tied to making sure the science is done right, hesitate to make any statements until all the cards are played.
“We know that last year we lost a few more animals than normal, but so far, nothing we’ve seen shows that we lost 40 or 60 percent of the herds,” DeVergie said. “Now, that might change, but we we’re hoping to find out just how bad it was when we get flying.”
Similar concern has been raised in the Gunnison Basin, when last winter the DOW was feeding an estimated 9,000 deer out of a population of more than twice that many. No one knows how many deer succumbed to last winter’s record snows, but the winter flights, along with hunter surveys, will help answer some of those questions, said Gunnison area wildlife manager J Wenum.
“All of us are looking forward to our annual classification flights,” he said. “Those flights typically start round the first of January and by the end of the month we will have a much better feel for what the impacts were.”