I will not be addressing all the issues raised in the post below,
rather focusing on the bird depicted in the linked image below.
http://ruhikant.smugmug.com/Birds/Spring-2013/28947899_bqnHq9#!i=2487927209&k=XHTbRDx&lb=1&s=O
Photos of this bird were first made available to the public by Leslie Houser
29 April through this eBird checklist
https://ebird.org/admin/reviewSub.htm?subID=S13931328
.
First to answer Ned's question about a photo of a bird known
to be a hybrid based on DNA or a banded as a chick? I do not
have that information. How often do we have that kind
of imagery of any putative hybrid? Certainly none exists of the
WEKI/COKI/Scissor-tailed Flycatcher from last fall near Sandusky
... yet I don't think anyone disputes that it was a hybrid.
And so I must ask why is that necessary?
When an American Black Duck sports a green sheen in the
head, a character not associated with that species but one
found in other species including Mallard, are we more comfortable
identifying the bird as a hybrid, or do we keep calling it an
American Black Duck. When we identify Brewster's and Lawrence's
Warblers, we do not do so as a consequence of some
genetic assay, but because the observed phenotype exhibits
a mix of characters we associate with two different species. And so,
we tend to use the caveat "apparent hybrid" only in some pairings so
familiar to us as these, we drop the phrase from usage.
Let us take a critical look at the bird in question.
What are definitive characters for White-faced Ibis.
I think we can agree that in breeding plumage, a white border of
FEATHERING around the bare skin of the face is good for White-faced
Ibis, and that is not an expected character of Glossy Ibis.
This bird exhibits the white feathering so not a Glossy Ibis (contrary to
one eBird report).
In a breeding adult Glossy, we do see a chalky blue edging of the
olive facial skin sharply demarcated and reaching the eye but not
wrapping around it. In a White-faced Ibis, of similar condition as exhibits
the white feathering, the facial skin is wholly reddish in color perhaps
fading slightly to pink at the edges in 'dull' birds.
But the bird in question clearly exhibits an olive patch of facial skin
suffused with plum. We also see a sharpy mark border of pale facial
color, not blue but something intermediate ... mauve perhaps.
Regardless of the color, regardless of any subjective arguments over
'intermediate' color including that of the eye, the presence of Glossy
Ibis facial PATTERN should be enough to eliminate White-faced Ibis
from consideration. I will also note that both written descriptions and
of what we see in the image of the legs can be said the "knees" are
with much of the tarsi olive ... not consistent with White-faced Ibis.
On the matter of frequency, I should hope Ohio birders could become
more familiar with the ABA publication "North American Birds" for
information outside of the immediate region. Hybridization has been
underway for more than a decade at Salt Plains N.W.R.* There is a 2003
article cited below. The research did not end there. In the past few
seasons about 80 blood samples for DNA have been obtained at Salt
Plains and similar work on the Gulf Coast (where these intermediate
birds have been seen) are slated in the near future.
* [I cannot speak directly to the question of frequency but will pass
along that the Refuge biologist at Salt plains has reported 50 hybrids
in a single day. If you still wish to treat these as representatives of
mere variation, then
you must answer the question why so much variation at this breeding
site where Glossy Ibis are seen annually within the colony, but this level
of variation is infrequent to non existent elsewhere.]
Oklahoma is a hotbed for variation. Here is a photo essay based on
a SINGLE day's photo shoot among a flock of 400 ibis in southwest
Oklahoma (a wetland just an hr from Lawton).
http://www.pbase.com/joe_grzybowski/ibis_heads
You will find Glossies, White-faced Ibis (which do exhibit substantial
variation), and presumed hybrids. Again, we presume them to be
hybrids, in the same vein as Blue-winged X Golden-winged hybrids,
because these individuals exhibit a mix of characters which should
be exclusive to the parentals.
It was using this experience, I addressed the particularly
difficult situation presented by 7 dark ibis at Ottawa N.W.R. last May.
Several hundred people observed these birds and about 80 reported
them to eBird. I received every conceivable combination of Glossy
and White-faced Ibis including a report of one as a hybrid (from a
very experienced observer). I spent months last fall gathering
what I could and going over photos, before concluding there were 3
Glossy Ibis and 4 White-faced Ibis. One aberrant WFIB, with
excessive white feathering, fell within the known variation (as
supported by two fellow members of the Oklahoma Bird Records
Committee) and exhibited no Glossy characters.
It is with this same experience of 8 years on the OKBRC, and
with the further support of Dr. Joe Grzybowski and Jim Arteburn
(authors of that 2003 paper), that I published Ohio's first documented
hybrid dark ibis in North American Birds. But by all means judge the
photo by Tom Bartlett for yourselves. You will find it in full color on
page 711 of Vol 65. No.4. The Nesting Season. 2011.
Should the OH BRC come to a different conclusion on any of these
birds, the entries in eBird will be adjusted accordingly as it is the
stipulated policy of eBird to do so, contrary to what you may have
read elsewhere.
However, as my name appears on the seasonal review I write for
North American Birds, I solely report my own conclusions in that
space, and I stand by all of the above identifications.
PLEASE direct all communications to [log in to unmask]
I do not monitor the oh-birds email address. I do read postings to
the listserv through the ABA website http://birding.aba.org/maillist/OH
cheers
Vic Fazio
18722 Newell Rd., Shaker Hts, OH 44122
401, SW F Ave., Rm 509, Lawton, OK 73501 (current thru Aug)
Regional Editor, North American Bird, OH-WV 2004-2013
State eBird Reviewer, OH 2005-2013; OK 2008-2013
Oklahoma Bird Records Committee, 2006-2013
________________________________
From: Ned Keller <[log in to unmask]>
To: [log in to unmask]
Sent: Wed, May 1, 2013 4:49:28 PM
Subject: [Ohio-birds] Fernald (Cincinnati) Ibis
The two Ibis from Fernald Preserve near Cincinnati were seen until
yesterday evening, but were not seen today (or at least, the only report
was negative).
There has been continuing discussion about their identity; but before I get
to that, I have a question: Does anyone have a link to an image of ANY
hybrid that is actually known to be such? I don't mean just a bird that
looks intermediate, but a bird from a hybrid nest that was banded as a
chick, an adult identified by DNA, or any other source of actual positive
knowledge of its identity.
Ruhikant Meetei has posted a link to a stunning image of one bird:
http://ruhikant.smugmug.com/Birds/Spring-2013/28947899_bqnHq9#!i=2487927209&k=XHTbRDx&lb=1&s=O
And here's a post from the Cincinnatibirds message board from Jack Stenger,
reposted by permission:
[quote begins]
There has been discussion in other forums about the identification of the
Fernald ibis. At least one knowledgeable birder thinks that the photos
clearly show a Glossy x White-faced hybrid based off the dark eye and
purplish facial skin. This is an interesting possibility, but I think it’s
hasty to conclusively identify this ibis as a hybrid. (For the record, I
have not seen this bird in the wild.)
The golden rule in documenting rare birds is that extraordinary claims
require extraordinary evidence. Although we birders tend to overlook it,
hybrids are way more extraordinary than non-hybrids.
Our knowledge of dark ibis hybridization seems hardly more than anecdotal –
interbreeding has only been documented in one location in Wyoming (Faulkner
2005), assumed in Oklahoma (Arterburn and Grzybowski 2003), and "apparent
hybrids" are reported widely in the east and west. Even the publications
documenting hybrids frequently use the word “apparent”. Interestingly, in
the area where their ranges overlap, the Gulf Coast, there are no reports
of hybridization (Ryder 1967, Duncan and Johnson 1977, Ryder and Manry
1994). If anybody knows of any other mixed-species breeding attempts I’d be
eager to hear them.
For this to be a hybrid, it means that the following probably occurred: an
individual Glossy Ibis would wander far out of range where there were no
other Glossy Ibis to breed with, mate with a White-faced Ibis, successfully
raise an offspring, which then shows up well out of range itself. Could it
happen? Sure. Did it happen? That would take extraordinary documentation.
Maybe this bird is a hybrid. But assuming that’s the case because of soft
part coloration is a large leap. A bird with duller eyes and skin than
expected (from a photo) does not seem enough to prove a hybrid, especially
considering that young ibises have duller eye/bare part coloration that
deepen in color as they age. Could this bird just be a “late bloomer” and
not yet in breeding condition? If a second year junco retained it’s hatch
year eye color, would we assume it is a hybrid? No, we would use the term
“aberrent”. Why is this same evidence conclusive proof of hybridization in
an ibis?
All references highlight how little we know about the phenotypic
variability, gene flow, and hybridization of Plegadis ibis. If there is one
thing we shouldn’t be, it’s sure. I encourage observers to keep an open
mind about the bird and document it as well as possible. A "hybrid"
identification should not be a default identification for unusual
individuals.
Anyway, I hope more people get to see these awesome birds.
References:
Arterburn, J. W. and J. A. Grzybowski. 2003. Hybridization between Glossy
and White-faced Ibises. North American Birds 57:136-139.
Faulkner, D. 2005. Hybridization and nesting of Glossy
Ibis(Plegadisfalcinellus)in Wyoming. North American Birds 59:382-384.
Ryder, R.A. 1967. Distribution, migration and mortality of the White-faced
Ibis (Plegadis chihi) in North America. Bird Banding 38: 257-277.
Ryder, R.A., and D.E. Manry. 1994. Whitefaced Ibis (Plegadis chihi). In The
Birds of North America, No. 130. (A. Poole and F. Gill, Eds.).
Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The
American Ornithologists’ Union.
[quote ends]
--
Ned Keller
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Ohio-birds mailing list, a service of the Ohio Ornithological Society.
Our thanks to Miami University for hosting this mailing list.
Additional discussions can be found in our forums, at www.ohiobirds.org/forum/.
You can join or leave the list, or change your options, at:
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