Amateur photographer Don Shank was at the Conowingo Dam to snap shots of magnificent bald eagles, not drab white gulls.

But when a gull in cerulean blue flapped by while he was warming himself in his car that December day, the East Lampeter Township man leapt into action.

He got 16 pictures of the bird in five seconds before it disappeared over the top of the Conowingo Dam.

The mystery of the startlingly blue gull on Dec. 21 has haunted Shank ever since. He's contacted government agencies, called up birding hotlines and even handed out the photos to birdwatchers at the Conowingo Dam, where he returns at least once a week.

About half, he says, don't believe his photo is real and accuse him of having doctored the picture on his computer.

"It just didn't happen," protests Shank, 75, who doesn't even know how to send a photo by e-mail. "I wouldn't know how to Photoshop a picture."

The consensus of birding experts is that the gull was dyed as part of a tracking research project.

Gulls, notorious groupies of landfills, have been  known to get into paint cans. But this gull is uniformly blue. Its striking plumage, from beak to claw,  seems to be no mistake.

One long shot is that the gull is from two colonies of nuisance gulls in Chicago that the U.S. Department of Agriculture caught and sprayed with blue dye last spring to find where they were coming from.

The appearance of blue gulls caused quite a stir a few weeks later when they started showing up in northwestern Indiana.

Until the tracking project was known, some speculated the gulls had been hit by paintballs or had blundered into toxic waste, or were otherwise abused.

The Chicago gulls were ring-billed gulls, according to published reports. Two local birdwatchers who were sent Shank's photo think it is of a herring gull. But last Sunday, a birdwatching expert from Delaware told Shank it was indeed a ring-billed gull.

But there are other problems with the Chicago story.

For one, gulls dyed last spring would likely have molted off at least some of the blue feathers by now, says Danny Bystrak, a wildlife biologist at the Bird Banding Lab at the federal government's  Patuxent Wildlife Research Center near Washington, D.C. The Conowingo bird seems freshly dyed.

And Bystrak finds it unlikely, though not impossible, that the gull would have migrated from Chicago to the Conowingo Dam.

The Bird Banding Lab is responsible for permitting all banding projects in the United States and recording sightings. Bystrak found two research projects that involved dying gulls blue in Maine, but neither appeared active for several years.

Scott Weidensaul, an internationally known birding expert and author from Schuylkill Haven, wonders if the gull is part of a tracking project from the other side of the Atlantic. European gulls are known to show up here from time to time.

Nor are painted birds here a first. Some powder-blue tundra swans dyed in Siberia turned up on the Susquehanna around Washington Boro in the early 1980s.

Tracking birds by attaching bands or coloring them has been around North America since John James Audubon in 1803 tied silver cords to the legs of a brood of phoebes near Philadelphia. He found that two nestlings returned to the neighborhood the following spring.

In 2001, some 54,397 gulls and terns were banded in the United States and Canada, with 1,341 bands recovered.

Central Pennsylvania birdwatcher Mark McConaughy says the blue gull at Conowingo will likely be ostracized from the main flock until it loses its unnatural feathers.

Wherever the ostentatious gull came from, Shank sure would like to know.

"I'm getting tired of being called a liar," he says.


Staff writer Ad Crable can be reached at acrable@LNPnews.com or 481-6029.