Five Eagle Chicks Poised to Leave their Nests on Catalina Island

AVALON, Calif. - May 27, 2014 - PRLog -- Five bald eagle chicks are poised to leave their Catalina Island nests in the coming days, thanks to the continuing efforts of the Institute for Wildlife Studies (IWS) and the Catalina Island Conservancy. DDT poisoning had extirpated the bald eagle from California’s Channel Islands until IWS and the Conservancy partnered to bring them back to Catalina, beginning in 1980.

One of the chicks can be seen on IWS’ live-streaming “eagle cam,” where millions have watched the bald eagles tending to their young. The eaglet has been spotted perched on the edge of the nest and extending its wings in apparent preparation for flight.

“The wildlife on Catalina is part of what makes the Island so special and unique," said Ann M. Muscat, Ph.D., president and CEO of the Conservancy."To have an eagle soar over while you’re hiking on a trail is a testament to the hard work and dedication of the many people who made possible the return of these majestic birds to Catalina. It’s a truly memorable experience.”

The Conservancy’s work to fulfill its mission of restoring and protecting the valuable natural resources of Catalina through a balance of conservation, education and recreation ensures that the bald eagle will be here today and for future generations.

Last year, 10 chicks flew or “fledged” from Catalina Island’s nests. Biologists aren’t certain why there were fewer eaglets on Catalina Island this year. But they pointed out that the age of the Catalina Island eagles may have played a role.

Peter Sharpe, Ph.D., who has been directing bald eagle restoration on Catalina for the IWS since 1997, said that 2014 has been a transitional year for Catalina’s eagles. He explained that, “three of the four pairs that failed had at least one new member that was nesting for the first time.”

Bald eagles generally breed around five years of age. “It can take a new pair upwards of three years before they become successful parents,” said Annie Little, biologist for U.S. Fish and Wildlife Service. “We fully expect the younger eagles on Catalina to breed successfully next year.”

Catalina is home to Crystal, one of the oldest females on the Channel Islands. At age 30, Little said, the eagle is “simply not as fertile as she once was.”

After two decades without an eagle sighting on Catalina Island, the Conservancy initially helped to fund the Bald Eagle Restoration Program in 1980. As additional funding became available, the IWS took over the program and manages it today with the Conservancy’s support directed to providing a healthy ecosystem for the birds.

DDT, a pesticide that was outlawed in 1972 was absorbed by the birds’ major prey, fish, then ingested by the eagles. It caused the eagles to lay eggs with weakened shells that cracked under the adults’ weight during incubation. Without young eagles to replace older individuals, the Catalina Island population died out.

A new generation of adult eagles began laying eggs in Catalina nests in 1987, but the eggs all broke before hatching. Analyses showed that the eggs had record levels of DDT contamination, indicating that DDT was still in the environment.

To assist the eagles, IWS biologists began retrieving the fragile eggs, hatching them off-site in incubators and returning healthy chicks to the nests, where the parents accepted them back and raised them. In 2007, IWS allowed two nesting pairs, which historically had the lowest DDT contamination in their eggs, to attempt to hatch young naturally. It turned out that DDT levels had finally decreased enough to allow bald eagles to successfully hatch eggs in the wild.

“We were excited to have successful breeding by the bald eagles on Catalina after almost 30 years of restoration efforts,” Sharpe said. “I didn’t expect the DDT contamination to fall to levels that would allow successful reproduction for decades.”

By 2009, all nests on Catalina were left to natural hatching and incubation. Thanks to the dedication of the IWS and its staff, working in cooperation with the Catalina Island Conservancy, Catalina-native bald eagles once again soar along the Island’s cliffs.