In South Dakota, prairie bird numbers decline due to drought
PIERRE, S.D. — Weather, one of every hunter’s most-fickle mistresses, has been particularly unkind to South Dakota this year.
A dry, warm spring, followed by a hot and even-drier summer has kept the grass from growing to it’s full potential, the Capital Journal reported. The flowers, shrubs and clovers that dot the grassland also have suffered from the lack of rain. And, by anecdotal accounts anyway, there are fewer insects on the landscape.
Extreme heat, extreme dryness, grass that’s too short and a lack of bugs all conspire to make being a baby grouse a losing proposition. With too-short grass, chicks become more vulnerable to predators. When it’s too hot, they die of heat exhaustion. And, when there are not enough bugs to go around, the baby birds starve to death.
That’s troubling news to those hunters who like chasing North America’s native game birds.
Grouse populations, specifically greater prairie chickens and sharptail grouse, which fill the state’s definition of prairie grouse, tend to be pretty cyclical in nature. Neither species is terribly long-lived.
So, when there’s a year that chicks struggle to survive, the population can plummet. Especially if there are two such years back-to-back. Population data on the birds is full of peaks and valleys. Invariably, the valleys follow hard winters or extreme droughts. The deepest troughs follow years with both deep snow and dry summers.
Luckily for South Dakota, the winter of 2016-2017 was relatively mild. That is, except for the north central part of the state. The area around Mobridge saw around 60 inches of snow and has spent most of the spring and summer mired in extreme drought.
Everywhere else had fairly normal snowfall and was mostly normal temperature-wise, save for a few weeks of abnormal cold. An early melt may have helped improve overwinter survival, too.
On the Fort Pierre National Grassland, for example, U.S. Forest Service biologists counted the second-highest number of dancing, adult-male prairie chickens on record. The highest number ever counted was found in 2016. Sharp tails seem to have done fairly well, too. Biologists counted the fourth-highest number of dancing males on record this spring.
Still, the summer-long drought has taken its toll. Dan Svingen, district ranger for the Fort Pierre National Grassland, said area farmers and ranchers have reported seeing smaller broods, generally, and seeing two, distinct, age groups.
“Some of the ranchers we talk to say they’re seeing broods with really small chicks and broods with big chicks; there’s really not much in between,” Svingen said.
That may mean a hard freeze about mid-way through prime nesting time in late May took a toll on grouse nests. That would mean more birds had to renest, which typically means smaller, less-successful broods. Couple that problem with a drought and there’s yet more reason to be concerned about the coming hunting season.
For all the year-to-year worry, though, the Fort Pierre National Grassland is in pretty good shape when it comes to grouse. It’s one of the very few places in the world where the greater prairie chicken is thriving. The long-term, population trend isn’t just stable, it’s growing and has been since about 1988.
The prairie chicken’s success in the Fort Pierre National Grassland comes down to one thing:
“If you have good habitat-quality, you’re going to have grouse,” Svingen said.
The Fort Pierre National Grassland has a unique set of circumstances that tends to favor prairie chickens. One of the most important of those circumstances, at least when it comes to prairie chickens, is the presence of a diverse mix of row crop and small-grain fields intermingled with huge blocks of grassland.
Greater prairie chickens evolved as creatures of the tall-grass prairie. Prior to white settlement of the prairie and Great Plains, the western limit of the prairie chicken’s range likely was, with a few exceptions, the Missouri River valley, at least in South Dakota.
As European settlers started moving into the Great Plains and planting small grains such as wheat, there’s evidence, according to the book “Grouse of the Plains and Mountains” published by the South Dakota Game, Fish and Parks Department, that the prairie-chicken population exploded. The birds thrived on waste grain as a late-fall and winter food source and, because there still was lots of grass available, the birds had plenty of nesting and brood-rearing success.
Prairie chickens appear to have expanded west right alongside the white settlers. But, by the middle of the 20th century, land use had shifted throughout much of what had been the tall-grass prairie and prairie chickens soon were extirpated, or nearly so, from much of their ancestral homeland. Iowa documented it’s last known prairie-chicken nest in 1952.
There are some remnant populations here and there in tall-grass-prairie states, Missouri and Minnesota are good examples. Iowa, meanwhile, tried to reintroduce prairie chickens starting in 1999. Success has been limited to the southwest portions of the state, according to the state’s Department of Natural Resources. The birds still are scarce in Iowa.
It was the rise of landscape-wide row cropping and the decline of cattle ranching in what used to be tall-grass prairie that was behind much of the prairie chicken’s decline, said Steve Belinda executive director of the North American Grouse Partnership.
“They need big areas with little fragmentation,” Belinda said.
Pheasants, by contrast, are a bit better adapted to places with more-limited grasslands. The non-native birds don’t require quite as much space and can make do with smaller chunks of grass, Belinda said.
“It’s pretty easy to grow pheasants in corners and fence rows,” he said.
Further west, South Dakota, Nebraska, Kansas and eastern Colorado still have enough grass to sustain prairie chickens, though much of their modern habitat is mixed-grass prairie not tall-grass. The more northern states tend to have fared better when it comes to grassland conversion owing, in part, to the size of grasslands, Belinda said.
“It’s a much bigger ecosystem,” he said.
That’s another reason why the Fort Pierre National Grassland is a prairie-chicken stronghold. Just about everywhere else, prairie-chicken numbers have begun a downward slide, Belinda said.
The greater prairie chicken’s little brother from the south, the lesser prairie chicken, has fared far worse. The southern Great Plains has seen much more conversion and tree growth since white settlers moved in. Fire, which used to keep trees in check on the plains, was treated as an enemy for the better part of a century. Lesser prairie chickens and the habitats they depend on have disappeared from about 90 percent of their historic range.
In 2014, the U.S. Fish and Wildlife Service decided to put the birds on the federal, threatened- and-endangered-species list. Ultimately, a federal, district court in Texas ordered that the FWS pull lesser prairie chickens from the list, saying that the service didn’t give enough consideration to a voluntary, conservation plan established for Oklahoma, Texas, Colorado, Kansas and New Mexico.
The plan cited by the Texas court was organized by the Western Association of Fish and Wildlife Agencies. It’s not all that different from the sage-grouse initiative that received so much press in 2015 and 2016.
Both plans rely on forging partnerships between landowners, conservation organizations and government agencies in order to restore degraded or fragmented habitat. The hope is that better habitat leads to increases in both birds’ populations, thus keeping them off the endangered list and preventing the FWS from imposing restrictions on agriculture and resource development in the birds’ range.
While greater prairie chickens are in much better shape population-wise, than the lesser prairie chicken, there’s still cause for concern, Belinda said. Grassland conversion, though slowed by a recent drop in grain prices, continues.
Part of the North American Grouse Partnership’s effort to keep prairie chickens around includes working with other conservation organizations to improve federal, conservation programs contained in the 2018 Farm Bill, Belinda said. The partnership also is working with landowners to find better ways to encourage them to keep conserving native landscapes and wildlife.
“If you don’t address their needs, they’re going to quit doing it,” Belinda said.
Sharp-tailed grouse numbers have remained fairly stable across their historic range. They aren’t as dependent on treeless grassland and have always lived in drier environments with shorter grass. Sharp tails tend to be less tolerant of cropland but their inclination to drier, hillier terrain with shorter grasses makes them less vulnerable to grassland conversion.
Sharpies tolerate trees much better than prairie chickens, so the spread of such things as the eastern red-cedar tree doesn’t hurt them as much. Also, sharp tails are much better adapted to extreme cold and snow. One only has to look at the bird’s feet to see why. They’ve got a natural version of snowshoes.
Prairie grouse, owing no doubt to where they live, how they live and how difficult that makes them to hunt, are nowhere near as popular with hunters as pheasants and quail. That means that they’ve often gotten the short end of the stick when it comes to research and conservation efforts.
In South Dakota, where pheasants are king, the Game Fish and Parks Department recently completed revising its grouse-management plan. It encompasses three species: prairie chickens, sharp-tailed grouse and, oddly enough, ruffed grouse. The plan serves as a sort of guiding document for the state’s grouse monitoring and conservation efforts, said Travis Runia, senior upland-game biologist.
Among the plan’s calls for the standards of working to improve population monitoring and promote habitat conservation, is an ambitious project aimed at being able to predict where prairie chickens and sharptails can be found based on the available habitat and its condition.
Runia said that he’s working on what’s called an occupancy model with biologists from North Dakota. The idea, he said, is to use existing population and habitat data to create thunderstorm maps that can show hunters, birders and scientists where they’re most likely to encounter either prairie chickens or sharp tails.
For game managers, though, there’s more to the project than simply predicting where grouse may be.
“Probably the most important thing it will do is give us a threshold for what amount of grass we need to sustain the population,” Runia said.
When the mapping portion of the project is finished, Runia said, it will be available to the public and can be shared with groups such as The North American Grouse Partnership to help with their conservation efforts. The South Dakota piece of the project and its resulting map won’t be available until late this fall, Runia said.