• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Elkhorn Slough, California (1 Viewer)

djleahy

Well-known member
Hi folks,

I snapped this guy fairly high overhead. Looks like a solid red-shouldered hawk to me. However, I had been watching some northern harriers just previously, and looking at Sibley's, it seems like a juvenile harrier would look similar. I think the buteo-esqueness shows here, but I thought I'd ask the experts.

One thing I'm specifically wondering about; both Peterson's and Sibley's talk about the "translucent window" in the base of the primaries for red-shouldered hawks. Seems like my shot should show this . . . is it visible? Maybe I don't quite understand what they mean by this.

DaveL
 

Attachments

  • IMG_5149_bf.jpg
    IMG_5149_bf.jpg
    53.3 KB · Views: 101
Thats defenitely Red-shouldered hawk.

I havent heard about the translucent primary base before, but the primaries are defenitely light colored like light is shining through
 
Thanks for the quick replies! I'm glad it's as clear as I was thinking.

Regarding the field mark, Sibley writes "All plumages show distinctive pale translucent crescent across outer primaries (by the most important field mark to watch for on a flying bird)." Peterson draws pictures that almost look like holes near the wingtips. I see the light area, but it doesn't quite pop to my eye like these texts describe. Ah, well.
 
If you look at the 'jizz' of the bird, as you say you can see the buteo likeness of the bird, the wide wings, bulging particularly towards the base, and bulk of the body would immediately detract from a harrier of any species.
 
Hi Dave.

Your raptor is indeed a Red-shouldered Hawk - and the ´window´on the outer primaries you have read about is also correct. In your bird - which is an adult - it doesn´t show up that well since the secondaries and inner primaries are also heavily backlit - but if you close your eyes a bit - it´s there - like it is on this one:

http://www.pbase.com/garrettlau/image/44483424

less obvious here:

http://www.pbase.com/jayseejay/image/72700378

and even better on these ones:

http://www.pbase.com/dadas115/image/43533436

http://www.pbase.com/dadas115/image/27832262

and this juvenile:

http://www.pbase.com/dadas115/image/50910052

on the upperwing on this: (California race elegans)

http://www.pbase.com/garrettlau/image/48656787

and because of the fully lit wing - not so obvious on this one:

http://www.pbase.com/garrettlau/image/49194295

The 'crescent' shaped panel on the Upperwing:

http://www.pbase.com/image/56541739

http://www.pbase.com/dadas115/image/43533435

http://www.pbase.com/image/25981008

If you reduce this image down to 20% - you will see that the 'crescent becomes more obvious:

http://www.pbase.com/image/28544172

'High up' -

http://www.pbase.com/image/29358456

Very obvious:

http://www.pbase.com/image/38252444

http://www.pbase.com/image/40473752

JanJ
 
Last edited:
Warning! This thread is more than 17 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Users who are viewing this thread

Back
Top