Why Florida's cormorants looked drunk.

Veterinarians may at last have found the cause of a mysterious and sometimes fatal disorder that turns big birds into fuddled wrecks with an odd stance, a goofy walk, and a tendency to shake their heads.

"People describe them as drunk," says veterinarian Christine Kreuder of Peninsula Equine Veterinarians in Menlo Park, Calif. However, the real problem for double-crested cormorants along Florida's Gulf Coast is probably toxic algae blooms, Kreuder told a joint meeting of the American Associations of Wildlife and Zoo Veterinarians in Omaha, Neb., on Oct. 20.

Afflicted birds have been turning up for some 20 years. The wildlife clinic on Sanibel Island, Fla., where Kreuder used to work, received 388 sick cormorants in 1995 and 1996, but Kreuder failed to find a viral or bacterial cause.

Pathologist Gregory D. Bossart of the University of Miami is developing a test for a toxin produced by algae. When Kreuder sent him tissue samples in 1997, Bossart found that toxin. He also detected it in common murres that got sick in Monterey Bay, Calif., David A. Jessup of the California Department of Fish and Game in Santa Cruz reported at the meeting. Kreuder points out that the findings in the two species provide the first direct evidence for toxic algal effects on wild birds.