August 6, 2008
Endangered Pelicans Thrive, Hitting 40-Year Peak
By Mark Prado, The Marin Independent Journal, Novato, Calif.
Aug. 5--The endangered brown pelican, which faced extinction in California 50 years ago, is returning in record numbers to the Farallon Islands, according to the Point Reyes Bird Observatory.
"It's good to see that there are that many on the Farallon Islands," said Melissa Pitkin, the observatory's education and outreach director. "It's an amazing story."
The bird observatory -- now known as PRBO Conservation Science- has been monitoring wildlife on the islands since 1968, when 363 of the birds were counted. At the time, the population was beginning to recover from DDT poisoning, a toxic pesticide which washed from fields and accumulated in the fish pelicans ate, causing their egg shells to thin and dooming embryos.
This year a record 5,856 pelicans were counted on Southeast Farallon Island in mid-July, researchers said.
"Only in 1984 were there counts over 5,000 on the island," said observatory biologist Russ Bradley. "The birds have now covered the marine terrace and are roosting in huge numbers in many other areas of the island as well. This number may increase, as pelican abundance usually peaks in the fall."
The pelican population fluctuated from less than 500 in the early 1970s to more than 2,000 later that decade. In 1984 the count climbed over 5,000, but then dropped in the late 1980s to less than 2,000. In the 1990s, the number fell below 1,000 and then rose to more than 4,000, before dropping to less than 3,000 by the end of the decade. There were about
1,000 at the beginning of this decade.
"The fluctuations reflect a variety of things, including an increase in the population and sometimes synchronous timing of the pelican's normal northward movement, as well as responses to anchovies and weather events such as El Ni o," Pitkin said.
The birds weigh between 6 and 12 pounds, grow to 3.5 feet in length and have wing spans of almost 8 feet. Pelicans are superlative divers, helping them reach fish including anchovies, sardines and shrimp. Brown pelicans also eat some invertebrates, such as squid. They are a familiar sight around fishing ports within their range, where they roost on piers, docks and fishing boats, ready to feast on fish scraps.
While Atlantic brown pelicans were removed from the federal endangered species list in 1985, Gulf Coast and California populations are still listed as endangered.
The brown pelican's worldwide population is estimated at 650,000, with some 400,000 in Peru.
"Pelicans now congregating in the Gulf of the Farallones can arrive from any Pacific coast (or) gulf of California breeding colony, but the majority likely belong to the Southern California Bight population (Channel Islands and northwestern Baja) where this year was a good but not great breeding year," said Dan Anderson, a pelican specialist at the University of California at Davis.
The Farallones are a national wildlife refuge managed by the U.S. Fish and Wildlife Service., and the birds will stay through next March before heading south again.
"Along with hatching-year birds, we're seeing a high proportion of birds born one and two years ago, pointing to good survival rates of late," Anderson said.
Contact Mark Prado via e-mail at [email protected]
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