By DAVE BUCHANAN
After a winter and late spring marking one of the wettest years in nearly a decade, this year’s hunting season — if you were lucky enough to get a license — is shaping up to be another great one in Northwest Colorado.
Not unexpectedly, after the winter’s deepest snows arrived in March, the time when big-game animals are most susceptible to winter mortality, Colorado Parks and Wildlife reduced the number of elk license available this fall by more than 1,000 from 2018.
Some of that reduction is the result of efforts to bring some over-populous herds down to desired levels. Some of it, however, is also due to a continued drop in elk calf production in the southern third of the state, which in turn limits the number of cow elk licenses available to hunters.
Overall, statewide CPW is issuing about 126,500 limited elk licenses this year, down from the 127,600 available in 2017. But portions of that number are up in other areas of the state, including the hunting hotbed of Northwest Colorado.
All licenses for rifle antlerless, muzzleloader as well as the first, fourth and late bull elk season are limited. Also, many GMUs also have limited licenses for archery and the second and third bull seasons.
Andy Holland, state big-game manager for CPW, told the Wildlife Commission in May that as more herds get close to desired population levels, further reductions in antlerless licenses are anticipated.
“You have to harvest a lot more animals to get to objective than you need to maintain that objective,” he says. “So when herds are at or near objective, as many of our herds are, you can’t harvest as many animals.”
The Southwest Region saw the largest reduction in license numbers, dropping 2,500 or about 9 percent of the total. In turn, the largest elk herd in the state, in the Bears Ears region of Northwest Colorado, saw an increase of 2,000 licenses, around 25 percent. “Essentially, that herd is cranking and we don’t want it to get away from us,” Holland says.
What helps in controlling the size of that herd is that about half of the private land in the area is enrolled in CPW’s Ranching For Wildlife program, which allots a large percentage the most-desirable licenses to ranch owners who open their land to public hunters after the paying hunters have left.
Because ranchers can sell bull elk licenses for high amounts, the majority of the public-hunt licenses are for cow elk. A CPW report indicates the success rate for private-land elk hunts in 2018 was around 44 percent, more than double the 29 percent success of all elk hunters.
The high success rate on RFW properties helps the agency control the elk population. “We rely this to keep the herd from getting too big,” Holland says.
Statewide elk numbers are estimated at 287,000, up slightly from the 282,00 estimated pre-hunt 2018.
Much of the reduction in licenses for the Southwest Region is tied to a continuing worrisome decline in calf production, for which the state and neighboring states are conducting several research projects.
The three-year average cow/calf ratio in the Southwest and Southeast regions is about 33 calves and 34 calves per 100 cows, respectively. That’s compared to the 47 calves/100 cows in the Northwest Region and a 41/100 ratio in the Northeast Region.
A map that Holland displayed to the wildlife commissioners was colored to illustrate cow/calf ratios and the game units with the lowest ratios; bright red for the lowest ratios changing to yellow, dominated the southern half of the Western Slope. The units’ colors gradually shifted toward dark green in the north, where some herds have ratios of 50 to 55 calves per 100 cows. What worries game managers is that more units are turning yellow, indicating a decline.
“We have much higher calf/cow ratios in the northern part of the state, but the yellow has crept north a bit, which is concerning,” Holland says. He adds researchers have noted a two-year drop in cow/calf ratios in the Northwest and Northeast regions, but so far not enough for concern.
No one knows for sure why fewer calves are reaching one-year of age in the lower third of the state. Guesses range from forage quality to hard winters to the long-term drought that has clutched that part of Colorado.
“We have several research projects on elk to get to the bottom of that,” Holland says.
However, this year’s classification flights done after the hunting season indicate the numbers have improved overall to around 42 calves per 100 cows. It’s accepted that a herd must produce 40 to 50 calves per year to be sustainable.
Testing provides critical calf ratio information
As part of a larger effort to ascertain why some elk herds in Colorado aren’t producing enough calves, CPW wildlife officers recently used a helicopter to capture 24 pregnant elk from the Roaring Fork River Valley.
The elk were flown to a testing facility where their health was checked and all were implanted with a vaginal transmitter that will tell researchers when the cows give birth this spring. The elk subsequently were returned to where they were captured.
When the calves are born, wildlife officers will capture them and fit them with collars or ear-tag transmitters to monitor their travel patterns and survival rates.
Known as the Avalanche Creek Elk Herd for its home range along the south side of Highway 82, the herd has seen cow/calf ratios from 30 to the low teens per 100 cows over the past decade, says CPW wildlife manager Mike Yamashita, addingan elk herd needs a birth rate of 40 to 50 calves per 100 cows to be sustainable.
The six-year research project will help determine if the cows aren’t getting pregnant or if the calves die before reaching one year of age.
Deer prudence: Population rebounding, spelling more hunting opportunities
Colorado’s deer herd continues to climb out of the hole created by the severe winter of 2007/2008, and, in response, this year there are more deer licenses and hunting opportunities for Colorado hunters.
Thanks to a stretch of relatively mild winters resulting in increased deer survival, CPW is on a seven-year run of gradually increasing hunter opportunity after drastically cutting deer licenses and opportunity a decade ago.
“Essentially we’re putting back licenses we cut in response to the severe West Slope-wide winter of 2007/2008,” says CPW state big-game manager Andy Holland. “It took a few years to realize the total magnitude of where we needed to go so we’re still adding those licenses back.”
While overall deer numbers have slowly been inching up in recent years, biologists and game managers agree that winters with prolonged cold and deep snows tend to keep deer herds from rebounding to desired levels.
“In Colorado, mule deer are usually the first (big-game) species affected when deep snow and extreme cold persist in winter range,” Holland says. ”And we typically have a severe winter on the Western Slope every 10 to 15 years.”
The state’s overall mule deer population jumped nearly 14.5 percent this year to an estimated 2018 statewide post-hunt population of 433,140. That’s still nearly 100,000 below the desired population objective of 532,000 but it’s a sign of how resilient mule deer can be given favorable conditions.
Despite dealing with a long-term drought that has severely impacted both winter and summer forage, “Our deer went into winter in really good body condition,” says Brandon Diamond, district wildlife manager for GMU 54 northwest of Gunnison. “Last year really gave us a good jump-start in the direction we need to go.”
He says it wasn’t until mid-winter that snow conditions began to stress deer and elk. Because the animals generally were in better body condition, “it wasn’t until midwinter that conditions got precarious,” he says.
Still, winter mortality across the Gunnison Basin was much less than feared, despite a March that saw a near-continuous string of storms that dumped up to 11 feet of snow in the high country. That area is one of the state’s five mule deer intensive monitoring areas and around 100 does and fawns wear radio-collars to track movement and survival rates.
“Gunnison had a severe spring and there was lot of concern about winter mortality, so we planned our deer licenses very conservatively,” Holland says. “It turned out we were too conservative, but you never can tell when the winter is going to break.”
Fawn survival in the Gunnison Basin is estimated at around 67 percent, he adds. Other monitoring areas showed wide-ranging survival trends, from well above average in Middle Park to “somewhat below average” in the White River herds. Three other monitoring areas, including the Gunnison Basin, were close to long-term averages for survival.
All this is good news for hunters. Colorado has long been known as one of the best mule-deer states and recent upticks in license demand reflect that positive outlook. “The demand for deer licenses is strong,” Holland says, adding that in 2018, 212,000 deer hunters applied for the 95,000 licenses available.
This year CPW biologists recommended issuing 100,500 licenses, an increase of 5,600 (6.5 percent). The total buck license recommendation is up 3,600 over 2018 to 5,500 licenses, a seven percent increase, Holland says. He cites a couple of reasons for the increase, including managing buck-to-doe ratios to proximate approved levels; to provide hunting opportunity; and to reduce or maintain existing levels of Chronic Wasting Disease in herds.
“That’s nothing new,” Holland says. “We’ve been managing CWD with buck harvest for 15 years in many herds around the state.”
Bucks are targeted in controlling CWD because they get the disease twice as often as does and mature bucks get the disease twice as often as young bucks, Holland says. “And we want to let hunters hunt,” he says. In 2018, 48 percent of all deer hunters harvested an animal.
Statewide, recommendations for rifle doe licenses is 16,100, up 900 licenses from 2018, due to some herds being above desired population levels (although many herds are still below desired levels). “In those herds below objective we are recommending the minimum of 10 doe licenses per hunt code,” Holland says. “We’re essentially putting deer licenses on hold in those units.”
Colorado adopted totally limited licenses for all deer hunting statewide in 1999 and since then licenses have been in high demand.
Deer survival case study: Gunnison Basin
How well big-game herds survive the winter is one of many factors wildlife managers take into account when determining how to allocate hunting licenses.
Every 10 years or so, Northwest Colorado gets a truly difficult winter — like that of 2007/2008, when deep snows, including more than 100 inches in the Gunnison Basin, and cold temperatures tested the ability of wildlife to survive (CPW reports hearing “of fawns up to their necks in snow”).
Measuring winter mortality, especially with deer, is difficult to do with accuracy. It can only be done by hiking the terrain, and often the remains simply disappear — some eaten by predators, others absorbed by the earth. Records from CPW show the survival rate for Gunnison Basin from 2008-2018 averages around 61 percent for fawns and 82 percent for does. This year, wildlife managers are cautiously saying survival appears to be “normal.”
“Generally, deer wintered okay throughout the Southwest Region wherever they were able to escape the deepest snows,” says CPW biologist Scott Wait. “But it was a difficult winter for deer.”
Collisions with cars also add to the tally. Snowfall historically forces deer and elk out of the high country to lower winter ranges; in the Gunnison area, most of this runs parallel with and overlaps U.S. Highway 50. Some years, the animals can adjust, staying high on rolling hills above the highway. “We did not have any type of catastrophic low survival rate this winter,” says GMU 54 CPW manager Brandon Diamond. “But a significant part of our mortality was roadkill.”
This year, March storms pushed deer to what little open space they could find, which is near the road. “It was an unfortunate situation,” Diamond says. “With the snow depth and the snow being hard and crusty, the deer ended up concentrated along Highway 50 and the southern end of Highway 135. But that’s what happens when we build infrastructure in the middle of winter range.”
CPW biologist Kevin Blecha says deer mortality this year in the Gunnison Basin appears about average, despite the toll created by vehicle collisions.
“Deer are dying in mass quantities every year in this basin whether we see it or not,” he says. Two years ago “you couldn’t see those deaths from Highway 50. This year is a much different story.”
Most of the deer entered the past winter in good body shape thanks in part to the dry, less-stressful winter of 2017-18, Blecha adds. Since winter survival depends largely on an animal’s fat reserves, more deer survived last winter, particularly if they weren’t massed along the highways. That, combined with conservative management of deer numbers, including under-predicting the number of bucks available for harvest over the last four years, convinced CPW to recommend increasing deer licenses in the Gunnison Basin for this fall.
“We’re trying to use the resource while it’s available,” Blecha says.“We’ve got a lot of bucks out there. The problem is you can’t stockpile bucks.”
With its harsh winter conditions, the Gunnison Basin goes through boom-and-bust cycles with deer populations — and its fawn survival rate is lower than the statewide estimates. But the area has seen its two lowest harvest years and the two highest years of fawn survival anywhere in the state.