[texbirds] green backed ad male rufous or allen's
- From: Matt Heindel <mtheindel@xxxxxxx>
- To: Texbirds <texbirds@xxxxxxxxxxxxx>
- Date: Mon, 26 Aug 2013 10:59:31 -0500
I am on the road and do not have the information on migration of green-backed
Rufous Hummingbirds handy, nor the specifics on density variation, but I'll
cover some topics at a broad level. And, as I said, anyone can play this game
any way they want. You want to call them X, call them X. But, these are more
philosophical matters than scientific ones.
But first, seriously, Gray-breasted Martin is considered to be a comparable
situation to a green-backed Rufous? If the comment is hyperbolic, fine-
anything to make a point, I suppose. But, If anyone thinks these situations are
the same, c'mon. With Purple Martins, we have hundreds of thousands every year
(or is it a million?). So, how many tens of millions over the past couple of
decades? How many Gray-breasted Martins? Ever? Without doing the research, I
would be surprised if there were even ten thousand of our hummers in question
in the past couple of decades (excluding west TX). So, the scale is so off the
charts it is just an unnecessary diversion. One thing that is true is that im
Gray-breasted Martin would be insanely difficult to detect. Given the default
by some astronomical advantage to PUMA,(millions to one) however, it would do
more to confuse the literature by clogging the airwaves with "martin" sp.
So, let's understand we can interpret this differently and how one sees it
might be dictated by what their goal is. I won't enter a debate about Type 1
and Type 2 errors as I ran out of steam on that topic ten years ago. Suffice it
to say we each have a philosophy along a continuum of what most likely reflects
what really is present on one end, versus the other end that says good records
might be lost in an effort to not include bad ones. No right or wrong, no need
for the hyper-emotion that seems to thrive in this world. Just different
desires, both of which should be included in any publications so the reader can
understand how records were included or excluded, so they might better put the
data through their own prism.
I do not think anyone has suggested green-backed Rufous Hummingbirds are CA
breeders, which means they are migrating a decent distance. Given their
migration, why wouldn't a bird be able to get to TX? Their migration is
typically much longer than that of Allen's, and although not a linear equation,
the length of migration might be an assist towards increasing wayward movement.
And, isn't it a given that Allen's makes up a smaller percentage of coastal
records, compared to Rufous. So, just rejecting the possibility of its
occurrence is something I do not share. I have never been a fan of the concept
that since a bird has not been recorded, it deserves no serious consideration.
Both of these species are low density migrants and/or vagrants to coastal TX.
There are great articles (e.g., Birding) on the explosion of hummers along the
TX and LA coast and it seems to be a rare event where humans might be providing
assistance to birds, and thus I think we are in the middle of a chapter that is
still being crafted. Allen's is not as rare as once thought (or perhaps not as
rare as it once WAS), so counting all green-backed adults as Allen's is not
going to significantly upend the understanding of the distribution. If people
want to do that, fine. But, don't take the attitude that this is the only
"right" philosophy. If you share my view that the hummer numbers along the
coast (in fall and winter) are changing in our lifetimes, then we ought to keep
our eyes open for what can actually be proven.
As for this green-backed Rufous being restricted as a migrant to CA, I don't
know, but don't think so. I had an ad male with what I thought was a green-back
in SE AZ one late July, but it turned out there were rufous flecks in it. Yet,
easily 90% of the back was green and when I was looking at it through bins, I
assumed it was an Allen's. (What got me was I thought the outer rects were
thick when it flicked its tail at the feeder, so I spent some time on it.) You
would have to have great looks to realize my AZ bird was not an Allen's and if
one accepts green-backed Rufous as Allen's, it will inevitably include
something like the bird I reference. That will not bother some people; but, it
would bother me. And remember, although birders (indeed, all humans) like
things in a binary fashion, the amount of green on the back of an ad male
Rufous is a continuum, so making a catch all is easy, but there will be some
that will not fit nicely.
A green-backed Rufous would be an excellent find, indeed, but throwing
everything into the Allen's bin will do nothing to help our knowledge. When I
see the insane list of rarities found in TX, the notion of a green backed
Rufous is not outlandish at all. I read the banding statistics and rationale
for the decision to call all of these birds Allen's, and, although I don't lose
sleep over it, I think it is simplistic, at least as it is handled today. if
the day comes when there is a green backed Rufous, what do you do with all the
green backed birds not identified by outer rects? Are they still going to be
Allen's? If you do not note the level of detail used in the identification, no
one will even know which records might be in question.
We had a different but related issue in CA, but this time with two vagrants:
Yellow Wagtail and Eastern Yellow Wagtail. All records have been for Eastern
YW, which was not particularly important until the species were split. At least
half of the birds are not identified beyond this species-pair, and that
identification is really difficult with ims. I had done a lot of museum work
(for one of the many articles that remain unwrittenâ¦â¦) and presented the
problem to the committee. So, we decided to put an asterisk next to the species
denoting the caveat that the congener might not always be eliminated. If a non
Eastern Yellow Wag (or even Citrine Wag in some cases) ever does occur, half of
the records will then have to be treated as "sp" not knowing which taxa was
involved. That is a different situation than with the hummers in question, but
that is a possible solution for these birds. What would be so painful about
denoting which Allen's are identified on back color (as opposed to banded
birds, those where r5 was studied, etc?) It is not as if we are overrun with
such reports. Over time, we'll be a lot smarter than we are today, but by
collecting more information and resisting an easy way out, we might accelerate
that learning curve. Alas, I fully expect the momentum of the green backed
Allen's bus to prevail- good enough.
Matt Heindel
Fair Oaks Ranch, TX
On Aug 26, 2013, at 7:44 AM, Fred Collins <fcndc@xxxxxxxx> wrote:
> It is my understanding that the green-backed Rufous form has never been
> documented in Texas. If memory serves me it has not been documented outside
> California where in a small area it may represent 5 percent of a local
> population.
>
> Therefore suggesting green backed adult Selasphorus are not Allen's is
> suggesting a rare or accidental occurrence instead of a regular occurring
> species.
>
> Would you have us start reporting all immature Purple Martins as Martin
> species because Grey-breasted HAS been recorded in Texas but in a roost of
> 100000 I did not conclusively ID all immatures as Purple.
>
> Until a green-backed Rufous is found in Texas or other SE states I do not
> think they should be seriously considered.
>
> Immature birds are a completely different matter.
>
> Fred Collins
> Waller
>
> Fred
> Sent from my iPhone
>
> On Aug 26, 2013, at 7:16 AM, Graham Floyd <spcgraham.floyd@xxxxxxxxx> wrote:
>
>> I want to thank Matt Heindel for his reply. A lot of information packed in
>> there that I probably wouldn't have gotten had my post not been so terribly
>> vague.
>> The bird in question was a male, and it's back was green, with the back of
>> its tail rufous creeping slightly up into the lower-back. Like in the
>> Sibley illustration of male Allen's & the green-backed Rufous male.
>>
>> Questions I have that may not have answers (yet), are:
>>
>> -Do these 5% of green-backed Rufous males occur in a particular geographic
>> area, or are they equally likely to occur anywhere? I think I saw a video
>> pointing out they follow the same migration routes year after year, so even
>> in migration do they occur on certain routes and not others?
>>
>> -While several Allen's and numerous Rufous were being banded last winter at
>> a private-Houston residence (the Williams perhaps?), there was some comment
>> regarding the molt phase of Allen's and Rufous Hummingbirds allowing
>> easy visual (vs in-hand) separation at that particular time-of-year. My
>> question thus becomes: Are there seasons when only Allen's have green-backs?
>>
>> Thanks Matt for sharing your knowledge. This is why texbirds as a forum
>> can never be replaced despite the plethora of other sites.
>>
>> Graham Floyd,
>> San Antonio
>>
>> On Monday, August 26, 2013, Matt Heindel wrote:
>>
>>> I have read this email a few times and can only assume the choice of
>>> English was not the best as the question does not make sense. (How would
>>> anyone be able to tell whether your green-backed bird was one or the other
>>> based on what is written?)
>>>
>>> So, I can imagine other questions that perhaps were meant. 1) Has anyone
>>> else seen a green-backed Selasphorus at Blucher and if so, what did they
>>> think it was? Well, again we'll assume you must be referring to an ad male,
>>> as all Allen's and all female Rufous (and im male) have green backs "just
>>> like the book." If it was not an ad male, forget about it with this level
>>> of detail. We were at Blucher and had heard of a detail-less report, so
>>> gave it a little time, but had no Selasphorus at all. I have not heard of
>>> other sightings, so for now, question 1 seems to be no.
>>>
>>> 2) Perhaps you are asking if you had an ad male Rufous/Allen's with an all
>>> green back, can you call it an Allen's? Well, you can call it anything you
>>> want, but �..There are several issues: first, given the "hot, tired" no
>>> picture thing, it is important to be confident that the back is 100% green.
>>> Not 90% green, which can look pretty darn green in many views. That is
>>> another level of detail missing. But, even if the back was 100% green, you
>>> enter another zone. Some people feel that the % of green-backed ad male
>>> Rufous is so low that it is safe to call something like this an Allen's. I
>>> understand that at some level, as data would seem to suggest we are talking
>>> a very small number (<5%). But, it feels funky to me. I could not imagine
>>> making up a checklist of stuff I was 95% sure of. What value is in that?
>>> The fact Allen's is more numerous in TX than was once thought (based on
>>> banding data) can argue for or against the notion of counting 95%+
>>> certainty birds. On the one hand, since we know they are a regular part of
>>> our avifauna, perhaps making a mistake here or there is not a big deal. I
>>> take the other route, however, as even when birders think they are not
>>> making mistakes, some are creeping in. Why lower the bar intentionally?
>>> And, since Allen's are regular enough, why not wait until one is seen well
>>> enough to eliminate the doubt?
>>>
>>> Matt Heindel
>>> Fair Oaks Ranch, TX
>>>
>>>
>>> On Aug 25, 2013, at 3:59 PM, Graham Floyd
>>> <spcgraham.floyd@xxxxxxxxx<javascript:_e({}, 'cvml',
>>> 'spcgraham.floyd@xxxxxxxxx');>>
>>> wrote:
>>>
>>> Hello texbirders,
>>> Last weekend at Blucher Park in Corpus Christi, I had a green-backed
>>> Selasphorus hummingbird. It looked just like the Sibley illustration of
>>> Allen's Hummingbird. I was too hot and miserable to pull out my camera,
>>> but the hummer was actively circling the TNC house visiting each feeder in
>>> the heat of the day. Is anyone able to tell whether this green-backed bird
>>> was a Rufous or Allen's?
>>>
>>> Graham Floyd,
>>> San Antonio, TX
>>>
>>>
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