[CT Birds] Probable Dark Morph Broad-winged Hawk

Mark Szantyr birdinggeek at gmail.com
Fri Nov 18 23:36:17 EST 2011


The problem with evaluating subspecies, color morphs, or hybrids is that sight records or even excellent photographs do not often provide  indesputable evidence of the identification that is being alleged. In many cases, even DNA evidence might not substantiate the allegation.  Many of the subspecies that get reported, Cassiar Junco for example, or even many Oregon Juncos, show up in CT during the fall and winter. Perhaps the only sure way to identify this subspecies is to locate it on the nesting grounds. The same is largely true for difficult to separate subspecies of Iceland Gull and Lesser Black-backed Gulls.  For any records committee to act on hybrids, morphs, or many subspecies, the very best result that can be hoped for is for the committee to say the critter shows characteristics that might be consistent with our understanding of a subspecies or morph, or hybrid pair.  Even the very obviously abberrant Tricolored-like Herons at Hammo this year, while showing characteristics that seem to be intermediate between Little Blue and Tricolored , are best left as probable hybrids in the absence of hard and fast DNA evidence. 

Mark 

On Nov 18, 2011, at 8:41 AM, jaybrd49 at aol.com wrote:

> 
> OK folks, here is the official word...yes, ARCC does review unusual morphs, subspecies, etc. As others have noted, the black brant is just such an example. Certain gulls have also been reported upon and discussed in previous years, and there has been substantial commentary over possible hybrids.
> 
> As with typical species reports, observers should develop detailed reports for these sightings. Reporting guidelines may be found on the COA web site under the Avian Records Committee link.  Additional questions may be addressed to me or to ARCC Secretary, Greg Hanisek.
> 
> Good Birding,
> 
> Jay Kaplan, Chair
> Avian Records Committee of Connecticut
> 
> 
> 
> 
> 
> -----Original Message-----
> From: Nick Bonomo <nbonomo at gmail.com>
> To: streatham2003 <streatham2003 at aol.com>
> Cc: ctbirds <ctbirds at lists.ctbirding.org>
> Sent: Fri, Nov 18, 2011 8:45 am
> Subject: Re: [CT Birds] Probable Dark Morph Broad-winged Hawk
> 
> 
> Hey Luke & others,
> 
> "I don't think the ARCC ever look at morphs or subspecies which I kind
> of think is a shame in some scenarios..."
> 
> For the record, the ARCC welcomes written and photographic
> documentation of any rare subspecies or morph. Though I am not sure of
> our exact bylaws regarding these things off the top of my head, it is
> *not* true that we do not ever review them. Recently reviewed records
> of "Black" Brant serve as an example. It's actually incredibly rare
> that we ever receive any reports of rare subspecies or morphs of
> otherwise common species. This may be due to either lack of observer
> interest or unawareness that we do review such things...or both. I,
> for one, highly encourage the review of rare subspecies/morphs, and
> I'm sure that most ARCC members feel the same way. Perhaps this is
> something the committee can more officially and publicly address in
> the near future.
> 
> Thanks for bringing it up Luke.
> 
> Nick Bonomo
> Wallingford, CT
> www.shorebirder.com
> 
> 
> On Thu, Nov 17, 2011 at 4:12 PM,  <streatham2003 at aol.com> wrote:
>> Hi Scott, Bill et al
>> 
>> 
>> An interesting report. Ligouri suggests strongly that shape is the key factor 
> in identifying dark morph hawks as plumage can be so similar, so that certainly 
> counts as a positive in your sighting. If lighting was anything like it was here 
> this morning (all day in fact) it's not surprising you didn't pick up details on 
> the underwing which would support your ID but also suggests that you need to be 
> careful with other plumage details that were observed. Lighting is an important 
> factor for all hawkwatchers to consider - it's amazing what harsh light or late 
> day/early morning light will do to the appearance of a bird.
>> 
>> Weighing against the sighting of a dark morph Broadie would be that they are 
> exceptionally uncommon here in the east as you probably know. I think Quaker has 
> maybe one record and even Braddock Bay where they have 30k Broadies on average a 
> season has only a handful of records (we didn't observe one in the circa 70k 
> birds I counted this spring). I would also think the date would count against 
> the likelihood of seeing a Broadie of any morph as well, but it has been a weird 
> year. I'm wondering why you haven't ruled out something more prosaic such as a 
> dark morph Rough-legged (the 'common' dark morph buteo out east) seeing as you 
> went through other possibilities - though not always illustrated that way in 
> standard guides their tale patterns can often have the same black and white 
> banding pattern that an adult dark Broad-winged would show and descibed in your 
> report. Nicely illustrated in this shot of a bird taken by Bob Marcott in the 
> Braddock area: http://php.democratandchronic
> le.com/blog/birds/wp-content/uploads/2008/02/roughlegdarkdoug.jpg
>> 
>> Anyway an interesting siting - I don't think the ARCC ever look at morphs or 
> subspecies which I kind of think is a shame in some scenarios so the final 
> decision rests with you guys.
>> 
>> Luke Tiller Greenwich
>> www.underclearskies.com
>> 
>> 
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> 
> _______________________________________________
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> 
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