"Although considered to be relatively common, all three of these species have been exhibiting declines at a continent-wide level," With said.
According to a 2007 report by The National Audubon Society, two of these species -- the grasshopper sparrow and eastern meadowlark -- have lost 62 percent and 75 percent, respectively, of their global population in the past 40 years.
With and her colleagues found that birds are not breeding successfully in the Flint Hills. With said that more than 80 percent of nests were destroyed by predators. They also found that birds nesting in native prairie hayfields were more successful than birds nesting in grazed grassland. She said this might be because in the Flint Hills, the hayfields were mown later than in other prairie regions, enabling birds to finish nesting before the nests are mowed under.
"These hayfields are a less disturbed habitat than other managed grasslands in the Flint Hills, 90 percent of which is grazed and up to two-thirds may be burned," With said.
The researchers suggest that land-management practices may offer only part of the explanation for declining bird populations.
"There was a drought one of the two years we studied the birds, and in that year birds didn't do well anywhere," With said. "Under global climate change, we may see more prolonged droughts and less frequent, but more intense storms. If rain comes as intense storms with hail, that could be just as lethal to the birds."
With said that more study is needed before recommendations can be made to help manage these bird populations. But she said that the results are still valuable because -- like a canary in a coal mine -- birds indicate a region's overall environmental health.
"The cattle industry is important economically to the region," With said. "The region is also ecologically important. The challenge is to what
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| Contact: Kimberly With kwith@k-state.edu 785-532-5040 Kansas State University Source:Eurekalert |