Pollution Suspected in Deformity of Wild Birds : Environment: A contaminant may be well distributed because diverse species with different diets are affected.

In 21 years of caring for sick and injured birds, Dave Siddon had never seen anything like it.

Over the past two months, eight birds have been brought into the Wildlife Images rehabilitation center from around the Rogue River Valley with crossed bills, missing eyes or both. They include two red-tailed hawks, an osprey, three kestrels, a Brewer’s blackbird and a robin.

“About three years ago we had a red-tailed hawk come in with a crossed bill,” said Siddon. “But this is the first time we’ve ever had this number of birds come in with such obvious physical anomalies.”

Among them is a red-tailed hawk with a crossed bill and missing one eye, including the orbital bone around the eye. It has been kept alive through force feeding. Tissue and blood samples from this bird could provide the best clues to solving the mystery.

The answer is likely complex. Red-tailed hawks eat small mammals, osprey prey on fish and robin eat worms and fruit, suggesting that if some contaminant is causing the deformities it is not limited to one place.

“If you are finding a wide range of animals feeding on a number of different things, that is pretty unusual and certainly of concern,” said Don Steffeck, chief of the environmental contaminants division at U.S. Fish and Wildlife Service in Portland. “Unfortunately, there is not any one element of contamination that can cause these.”

The prospect of some kind of pollution worries Arnie Abrams, who found the red-tailed hawk with the crossed bill and missing eye in his back yard in Ashland.

“I would sit out here on the deck in my back yard and look up with my binoculars at the nest and think about how good life is in southern Oregon,” Abrams said. “Maybe now it makes you think about how bad things can be.”

The deformities bring to mind two well-known cases of birth defects among birds: double-crested cormorants with crossed bills that started appearing in great numbers around the Great Lakes in the 1970s and the variety of deformed waterfowl on the Kesterson National Wildlife Refuge in central California in the 1980s.

Siddon’s birds don’t appear to match those from Kesterson, said Joe Skorupa, senior biologist in the environmental contaminants division for the U.S. Fish and Wildlife Service in Sacramento, Calif.

The deformities among the Kesterson birds were traced to the naturally occurring metal selenium, which was concentrated in irrigation water running off farms into ponds at the wildlife refuge. When female birds were exposed to high concentrations of selenium a week before laying their eggs, their young hatched with no eyes, missing lower bills, deformed upper bills or deformed legs and feet.

“I would be looking for some kind of organochlorine,” said Skorupa.

That’s the deadly family of chemicals that includes polychlorinated biphenyls, or PCBs, as well as dioxin and DDT.

Carol Schuler, supervising biologist for the U.S. Fish and Wildlife Service’s environmental contaminants division in Portland, plans to concentrate on those chemicals in her search.

She is arranging for contract laboratories to scan blood and tissue samples from the birds for metals and estrogen levels, too. The National Wildlife Health Laboratory in Madison, Wis., will do necropsies, the equivalent of autopsies on humans, to look for more insidious problems, such as deformities in reproductive organs.

Results of the tests should be available in several months.

PCBs were once commonly put in oil in electrical transformers to prevent fires. Dioxin, a byproduct of making paper, can cause problems in minute amounts. DDT, a pesticide, caused the swift decline in bald eagle and peregrine falcon populations by producing eggshells too thin to survive incubation. The chemicals have been outlawed for their toxicity. But spills and dumping have left them widespread around the nation.

When they get in the body, organochlorines can mimic the female hormone estrogen. That can cause deformities, as well as make males act like females.

Brent Palmer, an assistant professor of microanatomy at Ohio University, has been working with double-crested cormorants exposed to PCBs around Green Bay, Wis. Many of the birds have crossed bills and other anomalies related to estrogen mimicking.

“To get the crossed bills and missing eyes, if it is a pollution-induced effect, there had to be a lot of pollution,” involved with the Oregon birds, Palmer said.

“What makes this stuff so insidious is that when you see these gross changes in animals’ appearance, that may be just the tip of the iceberg,” he added. “We have other populations of animals like alligators in Florida, where the adults grow up normally, but their reproduction is impaired. The habitat looks wonderful, the adults look fine, but they cannot sustain their population, so you have the potential for a true environmental tragedy.”

Finding the contaminant that caused the deformities still leaves the question of its origin, Steffeck said.

There might even be some natural condition, such as malnutrition, to explain the deformities, said Skorupa.

“It sounds like the canaries trying to tell us something in the mine shaft,” said Skorupa. “Maybe we ought to start opening our eyes a little wider, sniffing under stones and trying to figure out what the canaries are trying to tell us. They are our early warning system.”