FORT JACKSON, La. (AP) -- The smallest victims are the biggest challenge for crews rescuing birds fouled with oil from the Gulf of Mexico spill.
There's no way to know how many chicks have been killed by the oil, or starved because their parents were rescued or died struggling in a slick.
"There are plenty of oiled babies out there," said Rebecca Dmytryk of the International Bird Rescue Research Center, one of the groups working to clean oiled animals.
The lucky ones end up in a cleaning center at Fort Jackson, a pre-Civil War historic site on the Mississippi River delta south of New Orleans.
Pelican chicks often come in cold because oil has matted down the fluffy down that's meant to keep them warm. They must be warmed quickly just to survive long enough to be cleaned. And the youngest must be taught to eat.
"They only know their parents regurgitating food into their mouths. They don't know how to pick stuff up," said Dmytryk, whose organization is working with Tri-State Bird Rescue, a company hired by BP to coordinate animal rescue and cleaning in Louisiana, Mississippi, Alabama and Florida.
That means tube feeding three times a day. Others, a bit older and accustomed to taking fish from a parent's throat, must be hand-fed until they can eat fish from a bowl.
Adults can be checked a few times a day, but babies needed two staffers' full-time attention to be sure they are eating and are warm.
Many adults and juvenile pelicans get coated with heavy oil diving for fish. That doesn't happen with the chicks, though they may wade into oily puddles or get smeared by oil from their parents' feathers.
In general, rescuers don't go into nesting colonies, said Mike Carloss, a Louisiana Department of Wildlife and Fisheries biologist. He said most rescued chicks were near shorelines or were on nests so low that oil washed onto them.
Lightly oiled chicks will lose the oil when they shed their down feathers, he said. "We've seen a lot of those birds in those stages make it. A lot of them are fledging now. It gives you hope that is the right thing to do."
Nearly 60 pelican chicks and more than 600 adults were brought to Fort Jackson in June after oil washed onto a rookery on Queen Bess and other nearby islands in coastal Louisiana.
They're among more than 1,000 oiled birds and more than 100 oiled sea turtles rescued since the BP-leased rig Deepwater Horizon exploded April 20, killing 11 workers. About three-quarters of the birds and all but a handful of turtles have been cleaned in Louisiana.
All but two of the sea turtles - a 150-pound oiled loggerhead dubbed Big Mama and an 85-pound loggerhead that was sick but free of oil - are juveniles, ranging from saucer- to dinner-plate size.
Doses of fluids, antibiotics and a mix of cod-liver oil and mayonnaise used to help break up the oil they've swallowed are administered based on the animal's weight. But the basic treatment is the same.
"The difference is it takes five people to lift Big Mama and her sister. It only takes one person to lift the little guys," said Michele Kelley, Louisiana's sea turtle and marine mammal stranding coordinator.
Baby turtles leave their sandy nests and head straight for the sea knowing everything a turtle needs to know.
Chicks need far more care.
Keeping them warm can be the biggest challenge, and tern chicks are among the hardest to keep alive because they're so small, said IBRRC staffer Mark Russell.
The birds lose body heat through their skin, and smaller animals have more skin in proportion to their size than larger creatures. Some of the tern chicks are smaller than a tennis ball.
The chicks also tend to be dehydrated and malnourished.
"If they're dehydrated, they don't want to eat because they feel sick," Russell said. And they're so small that it's hard to keep a tube down their throats to give water and liquid food.
In the week he'd been in Louisiana, he knew of two or three tern chicks that died, Russell said Friday.
Once a chick is eating on its own, staff have as little contact with it as possible.
"We don't want to be raising what is commonly referred to as a pier rat," said Wendy Fox, director of Pelican Harbor Seabird Station, the Miami rehabilitation center where the pelican chicks were moved Saturday.
The babies will be housed next to adult "role models," and eventually with adults, Fox said. Their pens also have pools deep enough to dive for fish. Pelicans take five to six months to reach independence.
At Fort Jackson, one of the youngsters perched alongside a pool and flapped its wings energetically.
"See that?" Holcomb said. "He's almost ready to learn to fly!"