What has become of Oklahoma songbirds?

The deerflies were biting, and the summer sun burned hot on the vast northern Oklahoma prairie as two researchers waited, hoping to catch a bird, any ordinary songbird.

They had strung what resembled badminton nets amid the dew-soaked grasses and wildflowers. But the morning was slipping by, and still no birds were entangled in the gentle mesh.A grasshopper sparrow broke the quiet: "Tup-tup zzzz. Tup-tup zzzz." A breeze - and nothing else - fluttered the nets, and nothing more. The two men fanned away the flies and kept waiting.

No one knows exactly why many once-abundant grassland birds are now hard to find.

But after five summers of patient study on the Tallgrass Prairie Preserve, the Sutton Avian Research Center is developing one of the most comprehensive looks yet at what might be done to halt the dwindling numbers.

"We get a lot of calls from people who say `Where are the meadowlarks? Where are the scissortail flycatchers?' " said Dan Reinking, a biologist at the Bartlesville center.

"Many people are noticing a decline in songbirds," he added.

The center expects to begin producing scientific papers on its findings by year's end. The study, the nation's largest on migratory grassland species, began in 1992 and includes observations from 5,000 nests and 4,500 banded birds.

Tracking the songsters has been a matter of careful observation and patient waiting.

On one summer excursion, the wait ends when a brown thrasher finds its flight cut short by the mist net.

Reinking emerges with the bird squawking indignantly in his hands. The biologist expertly tucks its beak under one finger, blows back the head feathers and looks for changes in the skull that indicate the bird's age.

The biologist also notes the sex of the bird and other characteristics, checks for wing wear and bands it for future tracking.

Combined with nest observations, the information tells researchers how well certain species are reproducing and surviving - the prime indicators of whether bird populations are going up or down.

Most of these songbirds are neither specifically threatened nor endangered; in that way, this project is unlike Sutton's previous work in helping to restore the bald eagle. Getting the public to understand why they should care isn't easy, Reinking acknowledges.