The birds do struggle and shriek as they're cleaned, and workers firmly hold their beaks shut. The birds eventually relax. The struggle is worth it, according to Holcomb, who says that if left untreated, the oil would kill the birds.
"The initial impact on the birds is externally," said Holcomb. "But what happens now is that they have these beautiful down jackets, [but once they're oiled] they are unable to insulate themselves from cold and warm weather."
"And they lose their buoyancy in the water, which is why you see them floundering and struggling to get out so they don't drown or get hypothermic," he said.
The entire rehabilitation process takes between seven and 10 days, or until the caretakers are certain the birds can regulate their own body temperatures and are able to fish.
Behind the warehouse, the pelicans are treated to cages that resemble their natural habitat. Small pools of water are constructed to help the birds get back into their routine.
The before-and-after of the bird baths is remarkable.
"These birds look amazingly better compared to how they looked when they came in," said Heather Nevill, the medical director of the International Bird Rescue Center.
"When they came in they were covered in that thick, chocolate brown oil and since they've been washed their feathers look fantastic. Now we can actually tell which birds have white heads and are adults," she said.
When the birds are strong enough, they'll get released into the wild off the coast of Florida in the hope that they will not get stuck in oil again. But Holcomb says that many of the older birds will return to Louisiana anyway, looking for their homes, now covered in oil.
So far, no birds who have been treated in the center have returned for cleaning a second time, but Holcomb is prepared to put any bird that comes to him through the cleaning assembly line again, should they need it.
"We're going to be here for a long, long time," he said. "But we're ready."