"I always say they're fondued," Jay Holcomb, executive director of the International Bird Rescue Research Center, said. "They look like they're dipped in it. And that's because they are. The reason for that is that they plunge into the oil to eat fish, they don't understand what the oil is, and they get covered in it."
When the birds are rescued, they're brought into the sanctuary and placed in wooden crates together. To clean the birds, rescuers first soak them in vegetable oil that they can "work into the feathers and loosen the oil up," Holcomb said.
After the oil, comes a series of baths with diluted dish detergent which is rubbed all over the animals, sometimes using toothbrushes to protect the bird's eyes.
Then the birds are blow dried and placed in makeshift pools where they can bathe and preen themselves. Remarkably, rescuers said they grow new feathers and created a refurbished coat in a little more than a week.
One fear rescuers have, Holcomb said, is that when the birds are released at cleaner beaches in Florida, many of the older ones will migrate back to their oil-soaked hunting grounds.
ABC News' David Muir, Emily Friedman and Jack Date contributed to this report.