falcon/hawk ID?

[Allen Hirsch]

This is a new one for me - being chased/harassed by a crow in Cesar Chavez Park (SF Bay Area) this afternoon. Hence the unusual HA.

With the naked eye, I figured it was a white-tailed kite initially, since it was flying where I usually see the kites. But then I saw the eye and markings were different, and its flight pattern told me it wasn't a WTK, as well.

Can't find a match in my field guide. Thanks in advance.

[Roy Priest]

Look up Male Northern Harrier and see if it matches.

[Doug Herr]

Look up Male Northern Harrier and see if it matches.

I agree, male Northern Harrier.

[John Chardine]

You can see the facial disc of feathers, which is a mark of the harriers. They use it like owls do- to enhance their ability to detect their prey by sound.

[Allen Hirsch]

I've seen lots of Northern harriers, but never one this white. Is it a morph or a juvie?

[Jeff Cashdollar]

HARRIERS. Subfamily Circinae
NORTHERN HARRIER Circus cyaneus

Slim hawks with slim wings (Peterson). Fly low, gliding with wings in a shallow V. One species in North America.

Dunn Alderfwe "Illustrated BIRDS of North America"
Owl like facial disk (as noted by John), distinctive in all ages and both sexes. Harriers generally perch low, and fly close to the ground with wings upraised.

Common in wetland and open fields.

[Paul Guris]

I've seen lots of Northern harriers, but never one this white. Is it a morph or a juvie?

Adult male.

[Allen Hirsch]

Thanks, everyone.

Then I've seen only female harriers all these years in the field, apparently.

[Paul Guris]

Allen, immatures are brown as well so it may just be adult males you're not seeing.

For northern raptors, often females and immatures are the ones more likely to come south. This is the situation for Snowy Owls. I believe one reason is that in some species the males are more likely to hang in and hold their territories year round. In NJ, I definitely see vastly more brown birds than gray.

Maybe Declan is more up to date since he seems to know his literature well, but I remember there being population studies someplace that showed more females than males in certain areas. Unfortunately that memory is decades old but if you're interested, it might be worth a little Google search time.