SAVANNAH - Among the 250 brown pelicans roosting on a sand bar on Georgia's Atlantic coast, wildlife biologist Tim Keyes managed to find a few with the numbered bands around their feet that identify them as survivors of a disaster more than 500 miles away.
The red bands worn by six of the large birds Keyes spotted last week mean they're among 140 brown pelicans relocated to the Georgia seaside last summer from Louisiana. Rescued from the fouled Gulf waters following the BP oil rig explosion, the pelicans had to be scrubbed of oil smothering their feathers before they could be airlifted to a new home.
More than eight months later, some of the rehabilitated pelicans have started returning to Georgia after migrating further south for the winter. Keyes, a coastal bird biologist with the state Department of Natural Resources, wants to know more than just how many come back. After the trauma the Gulf birds went through last year, he wonders if they'll reproduce during the nesting season that began in March.
"There's a lot of uncertainty with these rehabilitated birds," Keyes said. "It would be of great value to know if these birds are able to reproduce and raise young and do more than just be able to survive."
More than 600 oiled pelicans were plucked from the Gulf oil slick last year after a BP-leased oil rig blew up off the Louisiana coast in April, killing 11 workers. The birds were cleaned and nursed back to health at Fort Jackson, La. Once they were strong enough, groups of a few dozen at a time were flown to new homes with similar habitats on the coasts of Georgia, Florida and Texas.
Scientists aren't sure how many have chosen to stick with their new locations versus those that opted to go back to their old homes. And just because they survived the winter doesn't necessarily mean they escaped harm altogether.
"In general, the prognosis for oiled birds is not good - you can't expect survival rates to be extremely high," said Tom Stehn, a wildlife biologist at the Aransas National Wildlife Refuge on the Texas coast, where 172 rescued brown pelicans were released last year. "They're clean, but a lot of them have suffered internal organ damage from ingesting the oil."
Some pelicans with bands identifying them as relocated birds have been spotted back in the Gulf, but the total number of sightings hasn't been tallied, said Michael Seymour, a nongame ornithologist for the Louisiana Department of Wildlife and Fisheries.
"When we released those birds, it was because we didn't want them getting back in the oil," Seymour said. "But we of course expected some of those birds to come right back."
More than 550 brown pelicans have been found dead along the Gulf since the oil spill, though only 150 of them were visibly oiled, according to the U.S. Fish and Wildlife Service. Seymour said dead pelicans slathered in oil are still being found nearly a year after the BP spill began, though with far less frequency than last spring and summer.
It's also unclear how successful rescued pelicans will be at reproducing after being captured by wildlife rescuers and scrubbed clean with dish soap. In a study of brown pelicans that were cleaned and traced after a 1990 oil spill in Southern California, scientists found the rescued birds showed no signs of breeding afterward.
"Being captured oiled and going through all the rigmarole it takes to get the oil off them is all really stressful on any bird," said Greg Butcher, director of bird conservation for the National Audubon Society. "You've got to be a healthy bird to respond in a healthy reproductive manner."
Butcher said he believes tools and techniques used to clean oiled birds have improved enough in the last 20 years that the pelicans will be better able to bounce back.
What he's really curious to find out is how well formerly oiled but relocated pelicans reproduce compared to those that never needed rescuing and remained in Louisiana. The success birds on the Gulf coast have making babies could yield clues to whether the fish they eat and the water they drink have recovered or remain polluted.
A couple of attempts to count brown pelicans on the Gulf Coast are in the works that might give an early idea of how badly the oil spill hurt their overall numbers. The Audubon Society should have 2010 results from its annual Christmas bird count in mid-April, Butcher said, which will include pelican numbers from the Gulf.
Seymour, the Louisiana state ornithologist, said his agency should do its own survey as early as May looking at both the overall brown pelican population and how many chicks are being born at the height of the nesting season.
While it will take years to know the full extent of the damage, Seymour said, the good news is scientists have reams of data on brown pelicans from before the spill to compare to whatever they find in its aftermath. That's because brown pelicans, driven close to extinction by 1970, were monitored closely for nearly four decades before being removed from the endangered species list in 2009.
That means scientists should have enough historical numbers to tell fairly quickly if any dips in the pelicans' population or reproduction rates are within normal fluctuations or are severe enough to point to manmade causes.
"We definitely have that data going back far enough," Seymour said. "Of all the birds we have here in Louisiana, the one we've got that's been the most studied is certainly the brown pelican."
It was last June and July when Coast Guard planes arrived on the Georgia coast with crates carrying roughly 70 rehabilitated pelicans each trip. The birds were released near some boat docks in the port city of Brunswick, 60 miles south of Savannah.
The first batch had orange bands on their legs - the same as rehabilitated pelicans released in other states, Keyes said. The second group got red bands with identifying numbers to distinguish them as having come to Georgia. They returned to the wild among the state's small but healthy native population of brown pelicans, about 500 nesting pairs.
Keyes said about 43 of the Gulf pelicans relocated to Georgia have been spotted since their release last summer, some as many as three times. The reported sightings haven't come from too far away, ranging from Tybee Island off Savannah to Nassau Sound off the coast of northern Florida.
One other hopeful sign: Keyes hasn't gotten any reports of any of Georgia's adopted Gulf pelicans being found dead.
"We'll keep an eye out as the big numbers return to Georgia," Keyes said. "In about a month or so, we should know whether we've got these birds back in our local colonies. But there are a lot of unknowns."