Drought causes sever impact on wildlife, creates uncertainty for winter
Casper – “We are seeing a lot of new records around the country this year,” commented Wyoming Game and Fish Staff Biologist Steve Tessmann during the Sept. 13 Game and Fish Commission meeting. “In Wyoming, we set our third highest temperature records. We had both the second driest and the second hottest years since 1895 in the 12-month period between September 2011 and August 2012.”
With drought conditions plaguing the nation, Tessmann noted that a lot of focus has been on implications for crops and livestock grazing, but wildlife are suffering as well.
“We asked our Game and Fish regions to share with us what conditions are like around they state,” he added, noting that each of the regions are seeing similar patterns.
Jackson and Pinedale
“The Jackson/Pinedale region only received 25 percent of their normal precipitation in June. April, May and June were the driest on record since 1985,” he continued. “In higher elevations, conditions are better for big game.”
While production levels were near average at higher elevation, they were below normal on drier public lands.
“Sage grouse production appeared to be higher this year – that is a common theme,” Tessmann said. “When we have cold, wet storms in the spring, that is bad for game birds.”
This year, however, Tessmann noted that good residual cover and good nesting conditions resulting from a warm, dry spring resulted in a good hatch of chicks.
“As we get into the fall, we are starting to see lower survival rates of broods,” he said.
Cody and Sheridan regions
Moving to the Cody region, Tessmann marked that lower elevations received almost no moisture, with even sagebrush plants showing sign of moisture and heat stress.
“Big game are concentrating on and near agriculture lands,” he said. “We are seeing animals move onto the crop lands.”
Elk calf production and sage grouse brood numbers were near average, but deer and antelope fawn and bighorn sheep production levels were below average.
Sheridan also saw lower precipitation levels in the southern portion of the region, with near average pronghorn fawn and game bird brood production near or above average levels.
In the southern half of the state, marked by the Green River and Laramie regions, similar trends could be seen.
“Basically, in the Green River Region, there was no herbaceous growth below 7,000 feet,” Tessmann said of the area. “Above that, they did see better forage conditions, but the entire region has been under extreme drought conditions since May.”
As a result, fawn ratios for mule deer and pronghorn were below average. Sage grouse brood production also suffered in areas with less moisture, showing no chicks in those regions.
“Winter losses are predicted to be above average due to poor winter range conditions,” Tessmann explained.
“Laramie saw above normal temperatures, and they only received 15 percent of their average precipitation,” he commented. “They have had quite a few fires, with over 100,000 acres that burned.”
Tessmann added that some direct mortality of mule deer fawns and bighorn sheep lambs resulted from fire.
“The rangeland is in poor condition,” he continued. “Fires that burned were so hot and dry that they scorched the soil, killing the seed and rootstock, so recovery is going to take an extended period.”
Additionally, female sage grouse saw some mortality due to West Nile Virus in the region.
Casper and Lander
The final two regions in the state, the Casper and Lander regions, marked continued dry conditions.
“Pronghorn production and body size are below normal, and mule deer are below average,” Tessmann said. “Some of that is due to distribution. They are being seen in clearings on the mountain ranges where we aren’t used to the animals being.”
Animal condition is also poor, said Tessmann, adding that winter will be difficult as a result.
Casper showed limited water availability for big game and no production on rangelands.
“We did have some summer thunderstorms that moderated conditions in the Thunder Basin and the Black Hills,” he added, “but we are seeing major epizootic hemorrhagic disease outbreaks in the Black Hills and Wheatland area due to dry conditions.”
Overall, Tessmann noted that drought has had a substantial impact on Wyoming wildlife, with fawn production around the state to be variable, but below normal.
“Depredation is increasing where ungulates concentrate near green vegetation in agricultural areas producing forage,” summarized Tessmann. “Game bird nesting success appeared good, at least early on, and brood survival continues to be good in irrigated and higher lands.”
With winter looming ahead, Tessmann noted worries over the survival of wildlife.
“Nutritional condition of big game animals is very poor going into winter,” he said. “If we have a severe winter, we can expect die-offs. We are expecting higher than normal mortality due to conditions.”
He added that there may be renewed pressure on the WGFD to feed deer, especially if members of the public begin to see nutritionally stressed animal.
“One of the unfortunate things about drought is that the impacts extend beyond the drought year,” Tessmann commented. “Because of the poor condition going into this year, we expect fawn production next spring to be even lower, even if we do see better moisture.”
Saige Albert is managing editor of the Wyoming Livestock Roundup and can be reached at firstname.lastname@example.org.