Buras, Louisiana (CNN) -- The sign out front points the way: birds, please enter to the right; humans, enter on the left.

Huddled in a pen and covered in brown streaks of oil, a dozen pelicans await treatment after exposure to the pools of crude on the surface of the Gulf of Mexico.

Increasing numbers of birds are arriving at the Fort Jackson Oiled Wildlife Rehabilitation Center in this coastal Louisiana town as the environmental disaster in the Gulf stretches on. At least 50 birds were treated on Tuesday alone.

Wildlife workers say the birds get oiled when diving for fish. Their efforts at preening sometimes worsen the coating of crude on their feathers.

The lucky ones are found by state workers and volunteers in time to save their lives.

"The animals that are coming in are covered in oil," the center's Rebecca Dunne says. "But they are pretty healthy animals. So that makes us feel like like we have a chance to save them. We have been pretty successful so far."

While around 200 birds have been dead on arrival at the center, so far none of the 400 birds brought in alive have died.

But not all of them express their gratitude.

"If you let 'em loose, they'll bite ya," says one volunteer holding shut the bill of a brown bird tucked under his arm.

New arrivals get a physical, and a day to "de-stress." Next, it's time for a scrubbing. They're washed with Dawn soap, rinsed and dried.

Finally, it's out to the aviary pens out back -- labeled "pelican island" -- where they are kept for observation and recovery.

On Tuesday, top football stars from the Super Bowl-winning New Orleans Saints came out to thank the center's volunteers.

"It's all about doing whatever we can down here in south Louisiana and the Gulf Coast, to help these people come back," quarterback Drew Brees told CNN's John King.

After rehab, the birds are scheduled for release in Florida, where they are less likely to repeat their run-in with the spilled oil.

But not all birds are so lucky.

"For every bird they rescue, there are other birds that are oiled, but that they couldn't rescue," Louisiana Gov. Bobby Jindal says. "That is what is so heartbreaking to the people of Louisiana."

The latest Consolidated Fish and Wildlife Collection report says 380 oiled birds and 50 sea turtles have been rescued; 594 birds and 250 sea turtles have been found dead.

For better or for worse, more birds are being found and brought in each day. Workers are planning to build eight more receiving pens in the coming days to handle the increasing influx of winged guests.

CNN's Brian Todd contributed to this report.