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Just a raptor note

posted by Jerry Liguori at
on Wednesday, February 8, 2012 


Some adult hawks can look 'juvenile-like'. Check out this Cooper's Hawk I photographed in 1999 at the Goshute Mountains in Nevada ('click' to enlarge). The barring on the underside is much less dense than a typical adult Cooper's Hawk. I have seen this on a few birds over the years, and several that I was able to see well had been in their first adult plumage (note the juvenile outermost primary, not to be confused with a retained old adult primary). Not saying this is a 'second-year' plumage only, but it may be. It is very uncommon otherwise, and almost all Cooper's Hawks (and many other species) in their first adult plumage are identical or nearly identical to older adults.

Its just neat to share an oddball bird....I have many in my collection to share. Funny, I have numerous blips to post about accipiters...seems that they are always an ID issue.

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2 Comments:
Anonymous Derek Lyon said...

Does the barring on the primaries change from juvie to adult? I never looked for a difference in wing barring when trying to age accipters.

Can't wait for more details.

February 9, 2012 at 5:53 AM  
Anonymous Jerry Liguori said...

Hi Derek

It does differ slightly, the banding is more contrasty or bold on juveniles...I'll post a pic for you. Its much easier to see on the topside than from below. Retained, faded adult feathers in comparison are not quite brownish, they still have a grayish tint.

February 9, 2012 at 10:37 AM  

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