P.J. Hahn, director of Coastal Zone Management for Louisiana's Plaquemines Parrish, extracts a pelican from oil on Queen Bess Island on Saturday.
Even after cleaning, many birds die as a result of liver and kidney damage due to oil ingestion, according to German biologist Sylia Gaus, speaking to Spiegel Online. The birds use their beaks and tongues to clean toxic oil from their feathers, which are vital to keeping the animals warm and afloat.
Gaus said the "middle term" survival rate of cleaned birds is under 1 percent, and he therefore advocates that rescuers "kill, don't clean."
But Nils Warnock, a wildlife specialist with the Oiled Wildlife Care Network at the University of California, Davis, said: "The public demands that something be done.
"It's heart-wrenching—you see this totally oil-covered animal, the only way you can see that they're alive is that their little eye blinks," Warnock told National Geographic News. "That kills me every time."