Article

Prairie chickens face new threats

A century ago prairie chickens may have been the most common wild bird on the High Plains. Today's lesser prairie chicken population is thought to be just 3 percent of what it was a century ago. Wildlife experts say the reason is simple: native grasslands are disappearing and without the habitat they need, prairie chickens are dying off. ...And now wind turbines threaten to blanket parts of the grassland.

Coal mines had their canaries. Grasslands have their prairie chickens.

A century ago prairie chickens may have been the most common wild bird on the High Plains. Today's lesser prairie chicken population is thought to be just 3 percent of what it was a century ago.

Wildlife experts say the reason is simple: native grasslands are disappearing and without the habitat they need, prairie chickens are dying off.

"It's telling us about the health of the ecosystems there," says Barth Crouch, policy director for Playa Lakes Joint Venture, a group dedicated to conserving bird habitat in the Southern Plains.

Pressure on prairies comes from many directions. Roads cut slices through the grass. Oil and gas wells break up what once were vast open spaces. Regular field burning denudes the landscape, turning protective grass cover into smoke.

And now wind turbines threaten to blanket parts of the grassland.

More than 10 years ago, the federal government put the lesser prairie chicken on a watch list for species that are threatened or endangered. On a scale of 1 to 12 -- with 1 being the most endangered -- the bird was an 8, a ranking shared by dozens of other species. Year after year, it remained there... more [truncated due to possible copyright]  

Coal mines had their canaries. Grasslands have their prairie chickens.

A century ago prairie chickens may have been the most common wild bird on the High Plains. Today's lesser prairie chicken population is thought to be just 3 percent of what it was a century ago.

Wildlife experts say the reason is simple: native grasslands are disappearing and without the habitat they need, prairie chickens are dying off.

"It's telling us about the health of the ecosystems there," says Barth Crouch, policy director for Playa Lakes Joint Venture, a group dedicated to conserving bird habitat in the Southern Plains.

Pressure on prairies comes from many directions. Roads cut slices through the grass. Oil and gas wells break up what once were vast open spaces. Regular field burning denudes the landscape, turning protective grass cover into smoke.

And now wind turbines threaten to blanket parts of the grassland.

More than 10 years ago, the federal government put the lesser prairie chicken on a watch list for species that are threatened or endangered. On a scale of 1 to 12 -- with 1 being the most endangered -- the bird was an 8, a ranking shared by dozens of other species. Year after year, it remained there on the list.

Last last year, the U.S. Fish and Wildlife Service moved it up to a 2.

"It is the last step in the candidate process before we initiate listing," said Chris O'Meilia, biologist with the service. By "listing" he means designating the species as either "threatened" or "endangered."

"We will start the listing process in the very near future if things don't change," O'Meilia said.

They nest on the ground

When Crouch talks to ranchers about the health of their prairie, he sometimes has been known to do the football test.

"It's not a full-size, regulation football," Crouch says. "It's about half-size. You hand it to the landowner and say, 'Go out (into the pasture) and throw this.' If you can see the football you don't have good nesting cover."

It's not complicated: prairie chickens nest on the ground, in the wide open prairie. They are about the size of domestic chickens. It takes the hen two to three weeks to lay their clutch of eggs, and another 26 days before they hatch.

"She has to remain concealed for 40 days," says Jim Putnam, small game coordinator for the Kansas Department of Wildlife and Parks, and one of the state's leading experts on prairie chickens.

She doesn't usually succeed.

A study Putnam co-authored on the survival of juvenile lesser prairie chickens found that only 25 percent of the clutches hatched.

"Almost all the hens attempt a nest," Putnam said. "Almost all the nests are lost to predation. Where they have good cover, they have much better survival rates."

But hatchlings tracked by Putnam's study had it tough, too.

Within 14 days of hatching, more had no surviving chicks. Seven of every eight chicks that hatched died before the onset of the mating season 10 months later.

The booming of mating

Two species of prairie chicken -- the lesser and the greater -- are found in Kansas. The lesser prairie chicken is found almost exclusively in southwest Kansas (and into Oklahoma, Texas and New Mexico); the greater prairie chicken is found in the Flint Hills and in more eastern states.

These prairie grouse may be best known for their mating behavior. During the spring they assemble at dawn at leks -- a spot where males create a booming sound with esophageal air sacs. Older dominant males occupy the center, younger males on the periphery compete for central access. Females arrive in April and after mating find a nesting site, usually within two miles.

Prairie chicken hens are picky about where they nest. They rarely set up within a third of a mile of improved roads and give buildings two-thirds to a mile berth, depending on size.

And they are very suspicious of power lines. A study that is to be published in the journal "Conservation Biology" tracked the flight patterns of nesting hens over several years. More than 8,000 movements were tracked, said Don Wolfe, senior biologist at the Sutton Avian Research Center and one of the study's authors.

"What we found was that of those birds that were within one mile of a power line, only 1.2 percent of them crossed that power line," Wolfe said. "They're showing a pretty significant behavior modification there."

Perches for predators

The study underscores similar findings by other researchers. Wildlife experts believe the grouse have evolved to avoid tall structures, which are convenient perches for predators.

Before Europeans settled the West, Kansas was almost exclusively grassland. Today half of the state's 52.7 million acres are cultivated cropland, and about 16 million acres -- 30 percent -- are rangeland. Recent studies have noted that while relatively little land conversion has occurred since the mid-1980s, prairie chicken numbers continue to fall, suggesting a decline in quality of habitat.

According to the Kansas Department of Wildlife and Parks, hunters bagged an estimated 59,000 prairie chickens in 1991; now the annual take is estimated in the low hundreds.

Putnam says that hunting has a negligible effect on the modern prairie chicken population. Over the course of the six-year study, Putnam's group put radio tags on about 400 birds.

"Less than 2 percent of all mortality was due to hunting," Putnam said. "The reason they are declining is because of nest success and chick survival."

The habitat outlook is mixed. The U.S. Department of Agriculture's Conservation Reserve Program, which pays farmers to return cropland to pasture, has noticeably increased the number of lesser prairie chickens in southwest Kansas.

Today Kansas supports more than half the world's lesser prairie chicken population. By 2012, two-thirds of the CRP contracts in Kansas are scheduled to expire.

Climate change problems

And new pressures on the remaining grassland lie ahead.

"Climate change will cause increased strain on existing grazing lands that have historically been diminished by improper livestock grazing," the Department of Wildlife and Parks said in a position paper on the future of prairie chickens in Kansas.

Compounding that is the explosion of wind development that has started and is expected to accelerate. Wind farms can easily over more than 10,000 acres and in 2008 alone there were 36 requests to evaluate potential wind farm sites in Kansas.

"All the good wind is where all the good nesting grassland is," Crouch said.

Stephanie Manes, who is with the Ranchland Trust of Kansas, which was established by the Kansas Livestock Association, puts it even more strongly.

"Grasslands are the most imperiled ecosystems in the world," she says.

The wind industry markets itself as being environmentally friendly, and some wind developers are making a concerted effort to address the effect wind farms will have on native prairies. Last year Horizon Wind Energy, which developed and operates the Meridian Way Wind Farm in Cloud County, reached an agreement with Ranchland Trust to invest in a 20,000-acre, off-site habitat restoration program.

Whether these counter measures will reverse the decline remains to be seen. Here is the overview the U.S. Fish and Wildlife Service provided in support of its decision to change the lesser prairie chicken's priority number:

"The most serious threat to the lesser prairie chicken is the present and threatened destruction, modification, and curtailment of its habitat and range. This includes loss of habitat from conversion of native rangelands to introduced forages and cultivation; conversion of suitable restored habitat in the Conservation Reserve Program to cropland; cumulative habitat degradation caused by severe grazing; and energy development, including wind, oil and gas development.

"The magnitude of threats to the species from wind energy development and conversion of CRP lands to croplands has increased recently, both in terms of ongoing activity and potential activity expected in the next few years ... The threats put the viability of the lesser prairie chicken at substantial risk."


Source: http://www.salina.com/News/...

MAR 22 2009
http://www.windaction.org/posts/19507-prairie-chickens-face-new-threats
back to top