The International Bird Rescue Research Center in San Pedro has been caring… (Bob Chamberlin / Los Angeles…)
The mysterious pelican malady that left hundreds of the birds sick and stranded along the Oregon and California coasts this winter was probably caused by a combination of bad weather and fish shortages related to El Niño, state Department of Fish and Game officials said Monday.
After ruling out such potential causes as disease or marine toxins, a group of scientists from state and federal agencies, nonprofit groups and Sea World in San Diego concluded that a simple scarcity of pelican prey, such as anchovies and sardines, probably combined with winter storms to produce flocks of hungry, wet, soiled pelicans, dying on beaches or looking for handouts.
Of the hundreds of birds washed, warmed and fed at rescue centers, about a third died, and many that were not rescued also succumbed.
Fish and Game officials called it a "cyclical event" that amounted to a perfect storm of bad luck for the birds. Many had strayed too far north during their annual migration, then arrived back in California weak and emaciated, only to find their usual food sources depleted and the weather inclement. They began eating the wrong things, lost weight and got cold.
A similar event struck pelicans along the coast a year ago, although fewer turned up at rescue centers.
Some of the starving pelicans rescued in the last two months had a dirty residue on their feathers that compromised their waterproofing. The researchers speculate that runoff from heavy coastal rains may have been the cause.
Although this year's mass stranding of pelicans was one of the largest in recent years, researchers say it probably won't significantly damage the pelican population.
Some researchers have questioned why the pelicans flew so far north, and stayed so long, placing themselves at risk. One theory is that those pelicans were displaying traits that made them less fit for survival than their brethren who had the sense to head south before the fish ran out and the weather turned bad.
But Paul Kelway, spokesman for the International Bird Rescue Research Center, said at least one rescued pelican in San Pedro bore a tag that suggested it had survived a decade along the coast before the stranding, suggesting its survival skills were not impaired.
Rescue groups said calls about sick pelicans had fallen off sharply by last week, suggesting the worst may be over for the birds. The center in San Pedro has received only about a dozen sick pelicans since last week, far fewer than in January or early February.
"We certainly have seen a drop-off," Kelway said.
But some birds may still be struggling. Passersby who spot sick pelicans should not approach them, officials said. Note their location and call (800) 399-4253 in Los Angeles County or (866) 945-3911 elsewhere.