[CT Birds] Accipitor ID

Mntncougar at aol.com Mntncougar at aol.com
Mon Jul 21 14:57:40 EDT 2014

Joe, I think, based on the 2 photos you supplied, it is  unrealistic to 
flatly state the bird is a Coop. It well may be, but there is  nothing so 
diagnostic in those photos as to rule out a Sharpie. There are too  many things 
that can't be told from these pictures to make a certain ID in my  opinion, 
which is why I didn't respond and perhaps why none of the other LHP  
hawkwatch counters did either. 
It does appear that the bird is still in a molt, or, given that  it's a 
juvenile, may be still growing out it's first full set of flight  feathers. 
However, the tail is quite long for either species, and I doubt that  any 
remaining growth is going to change the shape very much. At the same time, I  can 
agree, the head PROJECTION,  which is the real ID key, does look long  for 
a Sharpie, although the head itself looks rather small in comparison to the  
body. It is possible the angle the photos were taken from has some 
influence on  the appearance. 
And in the 2nd photo the wings do look rather short for a  Coop. I don't 
think the wing shape in either photo can be considered  diagnostic.  It's true 
that juvenile Sharpies often have darker and more  extensive striping on 
the breast and belly, but it is extremely  variable,  and to use it alone 
would be a mistake. 
One thing not mentioned at all in this discussion is the  white on the tip 
of the tail. Generally a Coop will have more than a Sharpie and  more than 
is shown in the photos. There are some other appearance issues as  well.
But it's the things we cant see in those photos that are the  most 
important. Number one, how big is it? In the 2nd photo it looks fairly  small, but 
frankly that can't really be told from a photo. An experienced  hawk watcher 
will have a fairly good sense of size given that good of a look  (almost 
straight up) in the air. If it appears really small, chances greatly  increase 
that it's a sharpie. A small male is unmistakable. 
Number 2, how does it fly? Both species use "flap flap glide",  but one of 
the better identifiers is how forceful the "flap" is. A Coop  generally has 
a fairly strong, powerful looking stroke, while a Sharpie  usually looks 
relatively weak and tentative. And notice the word "relatively."  Beyond that, 
both birds tend to bounce around a bit, but it is much more  noticeable in a 
Sharpie, particularly if there is a good breeze blowing. 
Head projection is a much better indicator when the bird is  seen flying 
because you generally can see it from different angles. Sometimes  the head 
almost seems to disappear between the wings on a  Sharpie.
Were there any other birds with it? Was there any chasing going  on? 
Sharpies tend to chase both each other and Coops more than Coops do, though  both 
will, on occasion. Sharpies are somewhat more likely to be in pairs or  
groups than Coops are. 
Another question, of a different sort; what is the  relative abundance of 
the 2 species in the area where it was seen? At Light  House Point we have a 
relatively high count of Coopers Hawks, but in most places  on the east 
coast the Sharpie percentage is far higher. On the other hand,  If you see an 
accipitor in southeastern Arizona, 99 to 1 (or more) it's a Coop.  I've birded 
there for years and only this year did I see a Sharpie. Took  me  a long 
time to make my decision on it. This may seem an odd point, but  I think it 
applies the same as it would to a possible rarity sighting: always  answer why 
it isn't what you would expect to see first. 
Again, I'm not disputing that it may be a Coop, but I think we  have too 
little information to be certain.
Don Morgan
Coventry, Ct
---- Joseph Cala via CTBirds <ctbirds at lists.ctbirding.org> wrote:  
> All-
> One of the ID forums that I participate in had a  very lengthy debate over
> the ID of this accipiter, and I figured that  since this one species that 
> many folks struggle with -- and given  that we'll start seeing a lot more
> juveniles of these species in the  coming months -- a picture quiz might 
> fun.
> This  particular bird presents some very fun ID challenges -- I won't cite
>  which ones specifically because that would potentially give away the ID.
> This bird was seen in Boise, Idaho recently.  Here are the two  pictures
> that were presented:
> I'd love to hear everyone's opinions on this ID -- and why, if  you're
> interested in playing along.  As an FYI I've had two very  esteemed raptor
> ID experts (and authors) concur on the ID.
>  _______________________________________________

From: Joseph Cala <joseph.e.cala at gmail.com>
To:  ctbirds at lists.ctbirding.org
Subject: [CT Birds] Accipiter ID quiz -  Answer
<CAHXZuFTa-ymdRTZN3gS0G4hN0_mThjs8uRABKkamdmPXxDh9=Q at mail.gmail.com>
Content-Type:  text/plain; charset=UTF-8


Only received a few responses (and  see a few more on the forum) but
hopefully more of you were able to take a  look at the pictures and
formulate an ID.

I specifically picked this  bird because it represents probably the most
mis-ID'd hawk there is out  there.  The whole accipiter complex can be
difficult (remember the  recent backyard Goshawk reports/pics that all
turned out to be Cooper's  Hawks) but the most challenging in that complex
by far is male Cooper's Hawks  and female Sharp-shinned Hawks.

Most hawk watch folks or savvy birders  can instantly recognize a female
Cooper's Hawk or male Sharp-shinned  Hawk--the differences in flight and
size are pretty unmistakable.   Things become infinitely more difficult when
it's the other way around -- as  male Cooper's can be almost as small as
female Sharp-shinned with just a  couple of inches in overlap--obvious in
the hand, not in the field.

In  any event, the bird in question is in fact a male Cooper's Hawk.   The
larger head, unstreaked throat, sparse thin breast streaks that  fade
towards the tail all point towards that ID.  I know the tail is a  major
point of contention - it helps to note that the bird is currently in  molt
which is making the tail appear much more Sharp-shinned like than  the
normal graduated/rounded Cooper's tail.

The wings and profile of  the bird in the 1st picture definitely appear
Sharp-shinned at first glance,  but understand that the bird is in a 'wing
down-flap' and makes those wings  appear much stockier than they are --
which you can see in the 2nd picture  for comparison's sake.  The 2nd photo
shows less stocky, and much longer  wings.

Don Morgan,  Coventry
mntncougar at aol.com

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