[birding] Rough-legged Hawk parasitized by Bald Eagle

[Joel Geier]

Hi folks,

On Thursday afternoon, my son Wil and I noticed two large raptors
interacting in the air about 150 ft above a grass field on the north
side of Airlie Rd. (Polk County). They turned out to be an adult BALD
EAGLE and a light-morph ROUGH-LEGGED HAWK. 

The eagle harassed the Rough-legged Hawk until the hawk let go of a
vole-sized object, which the eagle snatched out of the air as it fell.
While still flying, the eagle bent its head down to its talons, and
appeared to swallow the (presumed) vole in a single gulp. Then it
resumed soaring above the hawk, as if expecting another meal. 

The hawk tried to drive off the eagle, making one close dive, but the
eagle simply gave a few flaps and soared higher, remaining above the
same field as the hawk's efforts gradually became more half-hearted. At
that point the situation seemed to settle into a waiting game, with both
raptors soaring separately but neither hunting, harassing, nor going
anywhere. Wil and I gave up first, and continued on our way.

Looking at the range maps, it appears that Rough-legged Hawks would not
have to contend with Bald Eagle parasitization over most of their
breeding range (except in parts of Alaska). This one did not seem to
have an effective way of driving off the eagle. On the other hand, I was
surprised to see a Bald Eagle work so hard to steal such a small meal.

Happy birding,
Joel

--
Joel Geier
Camp Adair area north of Corvallis