Ray Korpi forwarded to me this material:

> Andy said,
>
> Wheeler and Clark represent the "micro" view of raptors, Dunne the "macro."
> I did notice some attempts at reconciliation - Dunne
> wrote the forward in the new Wheeler and Clark book! Unfortunately, jizz and
> flight style are scantily mentioned in the text, even when obviously
> important in id. What a pity...

And Ray said:

I think all birders who are serious about getting better at identifying
hawks should get both a hawk id book (either drawings or photos) and
Dunne's jizz-based book. Having both in your arsenal really helps and
can make watching the hawks more fun.

I agree that "jizz" is important in recognizing species, and I use it
constantly. But I'll repeat the punch line from the lengthy section I
wrote on jizz in my shorebird book: jizz is a great way to recognize
common species, but it *should not* be used as a primary criterion to
define or identify rare species.

*Plumage characteristics*, and lots of them, are still the essence of
distinguishing species. They can be described reasonably objectively,
whereas "slender," "quick wingbeats," and "long-legged" (all of which would
indicate, say, a Red-shouldered Hawk) are more difficult to describe
objectively. "Slender" and "long-legged" are relative terms,
characteristics that could be confusing but would be more easily determined
if you had two species to compare, which doesn't happen all that often (at
least not 2 buteos sitting side-by-side on a branch). Both overall shape
and relative length of appendages differ depending on how the bird is
sitting. "Quick wingbeats" is even more subjective, and wingbeat speed
actually varies with flight conditions such as wind. A bird in a hurry
flaps its wings faster than one just cruising, and a molting bird with a
couple of primaries missing from its wings flies with faster wingbeats than
a bird with intact wings.

I've looked at an awful lot of accipiters vis-a-vis the "jizz" thing, and,
yes, you can often tell Cooper's from Sharp-shinned by relative head size,
but don't listen to me--instead, look at the photos in the hawk ID books to
realize that you'd be crazy to rely on this characteristic for a definitive
ID.

We badly need advanced bird ID courses for birders, in which all the
factors that go into making birds look as they do--basic plumage variation,
molt, albinism and other plumage aberrations, lighting, effects of weather
conditions, etc.--are clearly pointed out.

Dennis Paulson phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416