Date: 7/12/17 10:58 pm
From: Robert O'Brien <baro...>
Subject: [obol] Re: Taxonomic Changes (long)
Wayne has given an excellent summary of the recent changes and nonchanges
in speciation/nomenclature. I'll just add a few.additional comments.

1. I am surprised but gratified that the committee* unanimously* rejected
the renaming of Ring-necked to Ring-billed Duck. (pardon my previous
boo-boo).

2. Apparently the reason for not resplitting Yellow-rumped Warbler was the
lack of 'assotative breeding' in the convergence zone of the two forms in
British Columbia. Or, to quote a committee member who put it more
succinctly:

"NO. The problem here as I see it is the hybrid zone between *coronata* and
*auduboni*. There is no evidence that there is assortative mating where
they come together, and they hybridize like crazy."

i.e they seem to choose their mates randomly.

But, as Wayne relates, there seems to be selection against the resultant
hybrids and the hybrid zone appears to be stable rather than widening which
might be expected for a single species.

I would again encourage Oregon birders to try and document suspected
hybrids photographically, especially since both forms are common in
Oregon. Not an easy task unless one studies them, in their abundance,
quite closely. It is very tempting just to look at their throat color, or
their rumps, or just their Tweets. Of course, the *lack* of hybrids would
be more pertinent, which is much more difficult to do.

3. Like Wayne, I was disappointed and surprised at the unanimous decision
to lump Thayers into Iceland Gull.
In my brief few days at Kumlein's prime wintering location in St. Johns,
Newfoundland, I found only a single gull that was identical to Thayer's
(and might well have been a vagrant Thayer's). All others were 'clearly'
Kumlein's. And this is in agreement with local gull expert Bruce MacTavish
who told me at the time (~20 years ago) that a very small percentage (~1%)
of Kumlein's look just like Thayer's.

I'll conclude with a reproduction of a nice photo from the article Amar
Ayyash wrote for the current edition of Birding magazine just received.
This article was written before the committee's decision and reviews the
history of this (non)species. (Photo reproduced for educational purposes
only). This photo was taken by the venerable Jean Iron of the Hudson Bay
annual Shorebird Survey. Need I say more?

Bob OBrien

PS Here is the reference to the committee's individual comments:

http://checklist.aou.org/nacc/proposals/current_proposals.html

and a question to Wayne or others

What vote is required to accept a nomenclature change in the AOU?
Apparently a simple majority is not sufficient.






On Mon, Jul 10, 2017 at 1:46 PM, Wayne Hoffman <whoffman...> wrote:

> Hi -
>
> Thanks to Tom Crabtree, Bob Obrien, and others who have commented on the
> recent AOU (oops AOS) changes and posted links.
>
> I have gone through the committee members' posted comments, and have
> developed some summaries and my own commentary for the species most
> relevant to Oregon birding.
>
> Wayne
>
> 1. 1. Change genus of Latin names of Snow, Ross’s and Emperor
> geese from *Chen *to *Anser* [10 yes votes, 1 no]. One member
> commented, “…maintaining *Chen* renders *Anser* polyphyletic.” This is
> a common reason for changing genus names. What it means is some species in
> *Anser* are more closely related to those in *Chen* than to at least one
> of the others in *Anser * (Bar-headed Goose). The intent is that all of
> the species in a single genus should be *monophyletic,* meaning that they
> are all more closely related to each other than to any other species not
> included in that genus.
>
> 2. 2. Split Red Crossbills: YES!!! [8 yes, 2 no]. We have known for
> over 20 years that “Red Crossbill” is a complex of multiple species, so it
> is great to see its dismemberment commence. This is a special case
> involving an endemic to southern Idaho, less than 200 miles from Oregon,
> but hopefully the others will be resolved soon. More about crossbills in
> another post.
>
> 3. 3. Change the Latin name of the Northern Harrier to *Circus
> hudsonius* [all yes]. AOS now agrees with European ornithologists that
> American Northern Harrier is not the same species as Eurasian Hen Harrier.
>
> 4. 4 Split Yellow-rumped Warbler into 3 species [Failed: 4 votes to
> split, 5 against]. Recent research reports indicate that “Myrtle” and
> “Audubon’s” warble interbreed in NW Canada, and in at least part of that
> area, they seem to choose mates pretty randomly, HOWEVER there seems to be
> selection against the hybrids. So this is pretty much on the line in terms
> of species status, and I expect this split will not happen unless the
> makeup of the committee changes to include more people inclined to be
> “splitters.” I am not sure what other research results could be, that would
> change the current committee’s decision.
>
> 5. 5. Split Willet into 2 species. [failed, 6 yes, 4 no]. Two
> populations with overlapping ranges in winter and migration but separate
> breeding ranges. Some plumage and size differences, but not major. Some
> experimental evidence that Atlantic ones do not respond to calls of western
> ones. This split might happen in the future if the committee gets more
> splitters, or if more work on vocalizations amplifies these results.
>
> 6. 6. Change species limits in Juncos. They split the ones from
> southern Baja as a separate species, but did not change status in North
> America. General sense of the comments is that the current taxonomy north
> of Mexico might need changing, but they want more data before doing it.
>
> 7. 7. Lump Common Redpoll and Hoary Redpoll [failed 5 yes, 5 no].
> They want more evidence from breeding areas. The cited evidence is all
> over the map: some studies show assortative mating, some do not. Recent
> widely publicized study of wintering birds in the northeast did not seem to
> impress them much.
>
> 8. 8. Change Latin name of Northern Shrike to *Lanius borealis*.
> This is the result of splitting it from the Great Gray Shrike of Europe and
> western Asia, which retains the name *Lanius excubitor*. This split is
> not surprising but the name *excubitor* was so cool – I’ll miss it.
>
> 9. 9. Change Genus names of several dabbling ducks. Genetic studies
> show that *Anas* is paraphyletic, i.e. some *Anas* species are more
> closely related to some tropical species that are not currently included in *Anas
> *than to others that have been in *Anas*. Two possible ways to fix this
> would be to add those tropical species to *Anas* to make one very large
> monophyletic genus, or to split *Anas* into multiple monophyletic genera
> (what they did). This resurrects genus names that you might find in
> pre-1957 guides and references. Note that this “fix” is opposite to the
> one for geese. This is because they judged the differences between groups
> within *Anas* to be deeper (result of longer evolutionary divergence)
> than the differences between groups in *Anser*.
>
> 10. 10. Split Nashville Warbler [failed, 6 yes 4 no]. Two of the No
> voters seemed to waver, and suggested more info needed, so this may happen
> in the near future.
>
> 11. 11. Lump Thayer’s Gull into Iceland Gull. [unanimous Yes ]. I was
> disappointed by this. Essentially, they discounted a publication by the
> late Neal G. Smith that has been challenged as potentially fraudulent, then
> made the decision based on other information. I agree with tossing the
> Smith publication, but consider the info that they did use to be sketchy
> and incomplete. This info was mainly three studies, all before 2000, that
> found mixed colonies with apparent interbreeding of Thayer’s and
> (Kumlein’s) Iceland Gulls. Oddly, one piece of information that does not
> support lumping was not mentioned in the petition to lump, nor in the
> committee members comments, even though it was summarized in a publication
> co-authored by one of the authors of the petition (Jon Dunn). This is an
> analysis, summarized on p. 252 of Steve Howell and Jon Dunn’s book Gulls of
> the Americas, that shows variation in wingtips of a large number of
> Iceland Gulls, but indicates they could not find many Iceland X Thayers
> hybrids. So it appears adult hybrids are rare in the area where Kumlein’s
> Icelands winter, and our experience here is that hybrids are very rare on
> the West Coast where Thayer’s winter. So if these taxa are widely
> interbreeding, where do the hybrids go? Thus, this situation resembles
> that of Yellow-rumped Warblers: some, (but in this case not very
> extensive) evidence that they do not mate assortatively, but also not much
> evidence for hybrids being common. So maybe, like the warblers, hybrids do
> not survive very well? IMO the bottom line is that a lot more research
> needs to be done in the arctic and the potential wintering areas.
>
> 12. 12. Split Bell’s Vireo into a Western and an Eastern species
> [Failed 5 yes, 5 no]. Bell’s Vireos are rare strays to Oregon with only 2
> records in the OBRC archives, both from Fields. The issue for Oregon is
> that these and future occurrences might be hard to identify to species, and
> both are somewhat plausible strays to Oregon. This proposal failed because
> the two forms come closest to each other in New Mexico, and state officials
> denied permission to collect samples for genetic analyses (including
> denying permission to take samples of single feathers, or of blood, both of
> which are routinely done elsewhere without seriously hurting the birds).
> The committee expressed hope that in the future, the state would allow
> sampling.
>
>
> W
>
>
> W
>
>

 
Join us on Facebook!