Advertisement
YOU ARE HERE: LAT HomeCollections

The Pelican Is Getting Well Again

Wildlife: Species was once thought to be on the verge of extinction because of DDT contamination. While the birds are still endangered, their numbers have increased dramatically.

May 14, 1997|DARYL KELLEY | TIMES STAFF WRITER

VENTURA — This is a time of rebirth for a stately seabird once nearly wiped out by a virulent pesticide, but now flourishing on the rugged cliffs and wind-swept plateaus of two isolated islands off the Ventura coast.

Though still listed as a federal endangered species, California brown pelicans by the thousands are nesting on West Anacapa Island, a nature preserve closed to the public, and on tiny Santa Barbara Island 46 miles offshore.

Downy chicks are hatching as the peak spring birthing season arrives. If estimates are correct, more than 3,000 fledglings will spread their wings and fly away by late summer.

"It is like a giant maternity ward, a nursery, really," said Paige Martin, a biologist in charge of the seabird monitoring program at Channel Islands National Park in Ventura.

That is quite a change from 1970, when bets were that brown pelicans on both the East and West coasts would become extinct.

That year, just one chick on West Anacapa, the primary West Coast rookery, survived long enough to leave the nest. And only five chicks survived in Southern California and northern Baja California.

Things looked so bad for the brown pelican in the United States that its near-demise created a national furor that helped lead to the 1972 ban of the pesticide DDT and passage of the Endangered Species Act in 1973.

The brown pelican, bald eagle and peregrine falcon--once all common in Southern California--suffered horrendously as DDT caused their eggs' shells to become so thin that they were easily crushed during incubation.

The birds came upon the pesticide indirectly through the fish they ate. Anchovies, brown pelicans' favorite local food, were laden with the poison, which was washed into the ocean from Southland farms and piped miles off the Palos Verdes Peninsula by a large pesticide manufacturer.

New evidence shows that DDT is still killing the Channel Islands' eagles and harming peregrine falcon chicks. But the pesticide apparently has been less of a lasting problem for the brown pelican.

Although experts say pelican eggs still are thin, a decline in anchovies is now the primary reason that brown pelicans do not produce enough young to be officially declared a stable population and taken off the nation's list of endangered or threatened wildlife.

Yet the brown pelican, a poster bird of the budding environmental movement three decades ago, is generally considered a conservation success story.

On the East Coast, pelicans have come back to such an extent that they were declared recovered in 1985, and protective measures were removed. The West Coast recovery has been less dramatic, but it is still noteworthy, scientists say.

"I think it is a success story. It is one of the few endangered species in the country that has shown encouraging signs of recovery," said Dan Anderson, a UC Davis biologist who has studied the brown pelican since 1971.

Former UC Davis biologist Franklin Gress, who has studied West Anacapa pelicans more than anyone else, said from Santa Barbara Island last week that he considers the local pelican population stable, despite lower birth rates here than on the East Coast and in Mexico.

"We're a little hesitant to say, 'Yes, it's a 100% success,' but there's been a lot of improvement," he said. "They're recovering nicely, but they're still vulnerable."

Gress and Anderson support the reclassification of the brown pelican from endangered to threatened because the bird's numbers rebounded so quickly once DDT was banned.

Over the five years ending in 1973, an average of 722 pairs nested in Southern California and northern Baja. But those numbers surged to about 6,500 pairs from 1985 to 1989, when food was especially plentiful. The number hovers between 5,000 and 6,000 pairs today, scientists estimated.

The U.S. Fish and Wildlife Service began updating data on the species in 1995, anticipating a reclassification of the California brown pelican to threatened, or perhaps its removal altogether as a protected species, said biologist David Pereksta, who did the study.

That work ground to a halt because of federal budget cuts, but might be renewed in the next year or two, he said.

"The [pelican] recovery plan projected that Anacapa might be able to support 3,000 pairs, and that number has been routinely surpassed," Pereksta said. And even though the number of fledglings per nest is only two-thirds of that in Mexico, Gress said the rate of chick survival here has been consistent since the mid-1980s.

Still, the number of nesting pairs on the Channel Islands dropped precariously, to only a few hundred, in three El Nino years--1984, 1990 and 1992--as anchovies avoided the warmer waters, Pereksta said.

Anderson and other pelican experts also are studying the sudden deaths of about 1,500 brown pelicans killed by botulism at the Salton Sea last summer. And they are taking a long look at the gradual decline of anchovies near the Channel Islands.

"It's just like Roseanne Roseannadanna used to say on 'Saturday Night Live': 'It just goes to show you, it's always something,' " Anderson said. "With the pelican, it's always something. If it isn't DDT, it's the potential of oil [contamination] or changes in the food supply or the activities of man."

Today, the greatest threats to the species--which numbers about 100,000 when the crowded rookeries in mainland Mexico and the Gulf of California are counted--exist mostly in Mexico, Anderson said. Invasion of nesting areas by people has driven brown pelicans off some islands completely, and the Mexican government is inconsistent in its protection, he said.

That cannot be said about the Channel Islands National Park. Special permits are required before visitors can journey to the West Anacapa preserve. The three-hour boat trip to Santa Barbara Island, and the fact that a permit is required to leave hiking trails there, keep intruders at bay.

Advertisement
Los Angeles Times Articles
|
|
|