Published: May 10, 2010 11:14 PM EDT

PELICAN ISLAND NATIONAL WILDLIFE REFUGE, Fla. - The first two oiled birds found after a massive oil spill on the Gulf Coast have been cleaned and released in what could be the start of several relocations.

The U.S. Fish and Wildlife Service released the birds Monday at Pelican Island National Wildlife Refuge northeast of Vero Beach.

The birds are a Northern Gannet found in the Gulf and a Brown Pelican discovered on Stone Island on the Louisiana coast. Both were treated at the bird rehabilitation facility at Fort Jackson, La.

The primary recovery facility has treated only a few birds so far, and trying to quantify how many could be affected is difficult. Rescuers say it depends on where the oil travels in the Gulf, but that most oiled birds will be relocated out of the spill's trajectory.