Bald Eagle Diets Points to Intact Channel Islands Ecosystem

[Cara J]

A sustained natural diet of an animal that soars over the top of the food chain is a good indicator that an ecosystem is intact. New research tracking the eating habits of bald eagles (Haliaeetus leucocephalus) reintroduced to the Channel Islands of California over the past two decades shows the birds are thriving on diets of fish and seabirds — something that closely mimics the food they were probably eating in prehistoric times. “It’s just neat to see a successful reintroduction of a top predator like bald eagles,” said Seth Newsome, an assistant biology professor in University of New Mexico and a lead author in a study published recently in The Condor: Ornithological Applications. The authors of the study examined the diets of bald eagles through collecting prey remains from nests and doing carbon and nitrogen isotope analysis of feathers from 2010-2011. They then compared the results to data gathered from old nests from the early 20th century before the eagles disappeared from the Channel Islands due to human predation and DDT-related deaths. They found that modern day eagles’ diets differ a lot compared to those of the early 20th century, when the islands were mostly inhabited by ranchers. Historical [...]

 

Read more: http://wildlife.org/bald-eagle-diets-points-to-intact-channel-islands-ecosystem/