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A bald eagle that hatched on California’s Santa Cruz Island was recently found dead in northern Nevada. Eaglet "A-63" was the third bald eagle to be born in the wild on Santa Cruz Island since DDT pollution wiped out the population in the mid-twentieth century.
For the many fans who watched A-63 via live web cam — from his birth on April 13, to banding on June 8 and fledging from the nest on June 28 — his death is particularly heart-breaking.
Nature.org spoke with Peter Sharpe, biologist with the Institute for Wildlife Studies (IWS) about the eaglet’s death. According to Sharpe, the somber reality is that only 50 percent of eagles survive their first year — difficult odds for a bird trying to make a comeback.
nature.org: Do you know when A-63 left the nest on his journey from the island? Where did he travel along the way?
Peter Sharpe: He left the island on August 8th and flew in a nearly straight line from southern California to northeastern Nevada.
nature.org: How did you find out that A-63 had died?
Peter Sharpe: Eagle A-63 was found in the middle of a road in northern Nevada on August 15th. He was apparently hit by a car. A gentleman driving by saw our bird with blue wing markers and knew it was a federally tracked bird. There’s a phone number on the leg band and GPS unit that the eagle was wearing. The gentleman called to let us know.
nature.org: Do young eagles generally travel such long distances? How unusual is it that A-63 was found so far inland?
Peter Sharpe: Many of the eagles that we release or foster into nests leave the islands in August or September. They generally remain in the Pacific Coast states or British Columbia, but we have had a few fly through Nevada, Utah, Wyoming and Montana.
nature.org: It’s particularly sad to hear that A-63 was hit by a car. How did this happen — was he flying low, or scavenging on the ground?
Peter Sharpe: We can’t be certain, but most likely he was scavenging for food on the highway. We have had at least one other eagle hit by a vehicle while feeding on roadkill. They just don’t get out of the way of on-coming vehicles quickly enough.
nature.org: Don’t bald eagles mostly eat fish?
Peter Sharpe: Eagles leave their parents’ territory long before they start fishing, so they are primarily scavengers for their first year. They learn to fish later on.
nature.org: What are the most common reasons why an eaglet might not survive into adulthood?
Peter Sharpe: An estimated 50 percent of chicks don’t survive their first year. Starvation and accidents like these (getting hit by a vehicle or flying into a power line) are probably the most common sources of mortality.
nature.org: In light of this situation, can you explain why tracking and monitoring released wildlife is so important?
Peter Sharpe: Tracking and monitoring gives us invaluable information regarding the actual movements of the birds we work with on the Channel Islands. We are able to definitively know their movements without having to make assumptions as to where they may be or what may have happened to them.
nature.org: The national bald eagle population has bounced back from years of decline due to hunting, chemical contamination and habitat loss. In fact, bald eagles were removed from the endangered species list earlier this year. What are the biggest threats to their survival now?
Peter Sharpe: I think the biggest threat is the continued loss of habitat as we develop along lakes, rivers and oceans.
nature.org: Since A-63’s parents have established a nest on Santa Cruz Island, is it likely they will return next year to lay eggs and raise more chicks?
Peter Sharpe: They used the same nest for the past two years, so they will most likely return to the same nest next year.
nature.org: A-63 had a huge following of supportive fans who watched him grow up via the live web cam. As a biologist who probably sees a lot of life and death in the wild, do you have any perspective to offer us non-scientists who are sad to hear of A-63’s death?
Peter Sharpe: Even though I am aware of the survival rate of juvenile bald eagles, I’d like to think that the odds don’t apply to our birds and each one will live to old age. When a stunning loss like this occurs I am actually grateful to have the technology available to us so that the Good Samaritan could call us. This way we don’t have to wonder what happened to A-63. For me, not knowing is actually harder to bear.
nature.org: You’ve been leading bald eagle reintroduction efforts on the Channel Islands for ten years now. When young eagles don’t make it, what kind of effect does it have on your work?
Peter Sharpe: Frankly, it makes me work harder. We expect to lose about half of the eagles that we release during their first two years of life. We are trying to release enough eagles to overcome this initial mortality so that we continue to have young birds establishing new territories or replacing older birds that die.
Nature picture credits (top to bottom, left to right): Photo © Miguel Fairbanks (Santa Cruz Island); Photo © IWS (Peter Sharpe)
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