Inside Passage Blog

By Linda Lewis



June 29, 2007 – Now about that Eagle...


I have been reminded by several people that a brown eagle MIGHT be a female or it MIGHT be a juvenile of either sex. I knew that, but had leaned towards calling the eagle a female because it was so very large. But... that doesn't mean I'm right, so I should have been more equivocal in my description.
The erudite scholar, Jan Hersey (master proofreader for the 2nd Ed. of the SE AK Douglass cruising guide), sent me a good explanation and a quote from the David Sibley bird book. I'm going to pass her comments on so we can all learn more about eagles.

From Jan Hersey:
"Now about this eagle--how do you know it's a female? I believe the coloration is simply that of a juvenile. Takes about 4-5 years for them to acquire full white tail and head and eye changes from brown to yellow, as does beak. Females are larger than males, otherwise there's no difference. I've taken a fascinating class from Bud Anderson at Padilla Bay on raptors. Think he gives it in Seattle too, for about 5 weeks, during Feb., when Skagit Flats are loaded with some 16 varieties. I'll send you a web link to his organization if you like."
Here's what my David Sibley book says on eagles: "Adult distinctive, with white head and tail. Juvenile dark with white underwing coverts, whitish streaks on tail, and pale belly. Takes 4-5 years to acquire adult plumage; after one year develops white patches on belly and back, and after two years white on head and yellow bill begin to develop."
I'd guess this one might be starting its 2nd year as the book shows a first year with an all-brown belly." Another amazing factoid is that they're almost full size as soon as they fledge (leave the nest). We have a juvenile that's been hanging out around our house, though there aren't nearly as many eagles around as earlier in the spring."
Many thanks to you, Jan, for sending this on. I continue to appreciate your terrific skills and vast knowledge base.

Linda & Dave
M/V Royal Sounder



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