Thanks for that Kumar,
A search on the net for images of breeding birds easily confirms the separation
point of the two taxa as Afganistan, it's very clear cut without a cline.
Looking at photos on the Net, nom. ibis can be traced all the way to northern
Iran but a short distance away (by Cattle Egret standards) in Pakistan the
birds are decidedly coromandus. I have looked for evidence of obvious hybrids
and couldn't find it, but the missing piece in the jigsaw is Afghanistan, can't
find any digital images from there, I wonder why that would be. If any birds do
get either way across Afghanistan they aren't having any impact on the
distribution of breeding plumage on head for either of the recipient
populations which is very surprising considering their mobility and pioneering
tendencies elsewhere. The DNA indicates two subspecies of a single species
according to published data but something is preventing cline from one to the
other of what is otherwise a very mobile taxon. Maybe it's a genetic standoff
where neither ssp can invade the other with big enough numbers to effect a
visual difference but when invading a Cattle Egret free zone like Australia or
America for the first time you only need a handful of birds in theory to
establish a new population.
Are Cattle Egrets breeding anywhere in Afghanistan? they definitely occur
there, this could be where the answer is to be found.
The above is decidedly unscientific in approach but does easily confirm the
scenario as described by yourself. An interesting and perplexing subject and I
look forward to the forthcoming paper in Dutch Birding by Bharat Jethva.
Cheers Jeff.
-----Original Message-----
From:
On Behalf Of Kumar Ghorpade
Sent: Thursday, 1 September 2011 9:48 PM
To: ; ;
;
Subject: Re: [Birding-Aus] [OB] "Eastern" Cattle Egret, Bubulcus coromandus
Since I am currently working on a "Working Handlist of Indian Ornithology"
(update of Ripley’s 1982 New Synopsis) and preparing keys to polytypic species
recorded in our subregion, may I offer some scientific FACTS on this question ?
NOTE :
1. The Cattle Egret is better placed in the genus Bubulcus (non-aquatic, etc.)
than in Ardea or Ardeola (aquatic, etc.), which latter genera are probably
polyphyletic as currently used.
2. B. coromandus and B. ibis are currently recognized to be separate species
and also are allopatric as natural populations.
3. Dickinson (2003: 87) gives B. ibis range as "Spain to Iran, N and C Africa
to Mascarene and Seychelles Is.; E Nth. America, C and N Sth. America" And
that of B. coromandus as "India and Pakistan to S Japan, Philippines,
Indonesia,” [further matter missing, lapsus ?]
4. The Australian populations are B. coromandus as per figures in Pizzey &
Knight (2003: 112-113). These authors state that colonization of the Northern
Territory happened “probably from Indonesia in 1940s as part of worldwide
expansion.” They curiously end with the word “cosmopolitan” which certainly is
not quite correct! Usual irresponsibility and carelessness of field-guiders!
5. Breeding birds are quite diagnostic in the two species, as reference to
Sinclair et al. (2002: 62-63) will reveal from the breeding adult painting in
that field guide to birds of southern Africa.
6. Our latest and most carefully prepared reference guide (Rasmussen &
Anderton, 2005) has data which will substantiate recognition of TWO, and not
one, “cosmopolitan(!)” Cattle Egret species. The scientifically drafted text
volume (Vol. 2, p. 58) by a well trained and experienced ornithologist states
that “Consistent differences between Bubulcus ibis and B. coromandus in
breeding plumage, proportions and vocalizations indicate they are better
treated as two species.” They write that B. coromandus was “self-introduced
Australasia” and “once collected Chagos (Bourne 1971)” where it evidently
occurred as a vagrant. In their field guide (Vol. 1, Plate 7 & 9) they
characterize B. ibis as being “similar but stockier, in breeding plumage with
orange-buff mainly on crown, breast and mantle” ONLY and not more extensively
as in B. coromandus. In Vol. 1 they write that B. ibis “was introduced in 1955
from Seychelles to Chagos, where
now well established.”
Being a trained systematic entomologist and a bird-watcher in India from
1955, I believe our current species identities, mainly in guides prepared for a
commercial amateur market, are doubtful and not correctly diagnosed. I have
made my point in a recent paper (2011) in Current Science (100(7): 981-983).
Taxonomic research over the past 300 years or so has shown, to people who
can understand and accept, that speciation occurs over time principally by
geographic isolation, carried out either by active dispersal or by passive
vicariance. Being highly mobile (like e.g., large birds of prey) does NOT mean
that every species can migrate (or emigrate, like B. ibis into the Americas)
“coolly” and expand ranges, as has been indicated, and cautioned, in research
articles way back in the 19th Century. Diagnostic characters can also be very
“minor” (for binocular/camera-enabled humans, without “bird-in-the-hand”) but
they do exist between sibling and allopatric species which have unfortunately
been “downgraded” as RACES by lazy/confused/tired persons from the “Rothschild
Gang” (E. Hartert, K. Jordan) flooded with copious exotic material, and COPIED
by subsequent authors to this day without proper taxonomic reviews being done
or even
attempted. Edward Dickinson and others are working on this in their
“Systematic Notes on Asian Birds” being published in the Netherlands from 2000,
but even these are nowhere near adequate as a working taxonomist like me should
know and analyse!
Dickinson’s (2003) World Checklist is a close to accurate, holistic work
giving ALL so-called races currently worth a trinomial name, and not oblivion
in synonymy. For India and adjacent countries I am now engaged in finding out,
with my expertise in insects, which of our “subspecies” are really good species
and which others are just variants and within a cline, without population
breaks into genetically distinct species. Even good photographs of diagnostic
characters can help separate some of which are currently believed to be poorly
differentiated races. There is a lot of work in the field for amateur
bird-watchers, but careful, honest, objective documentation is a prime
requirement as also collaboration with experienced museum specialists with
adequate databases (specimens, literature, etc.) at hand. Cheers,
Dr Kumar Ghorpade (B.Sc., M.Sc., Ph.D.), Smithsonian Postdoctoral Fellow
(1982-83)
Postal address: P.O. Box 221, K.C. Park Post Office, Dharwar 580 008, INDIA
Currently: Post-Graduate Teacher & Research Associate in Systematic Entomology,
University of Agricultural Sciences, Krishi Nagar, Dharwar 580 005, Karnataka,
INDIA
Editor : HUMEA, Field Ornithology (1993-), PERDICULA (Monthly Notes on
Dravidian Ornithology 1999-)
Life member--Bombay Natural History Society, Madras Naturalists' Society,
Birdwatchers Society of Andhra Pradesh, etc.
--- On Tue, 30/8/11, Bharat Jethva <> wrote:
From: Bharat Jethva <>
Subject: Re: [OB] Eastern Cattle Egret
To: "John Penhallurick"
<>
Cc: "'Birding-aus'" <>
Date: Tuesday, 30 August, 2011, 1:17 PM
Dear Dr John Penhallurick,
I agree with you, I also don't think that it could be a separate species ! I
hope they have done detailed research when they accept it !
Best wishesDr. Bharat Jethva
--- On Tue, 30/8/11, John Penhallurick <> wrote:
From: John Penhallurick <>
Subject: [OB] Eastern Cattle Egret
To:
Cc: "'Birding-aus'" <>
Date: Tuesday, 30 August, 2011, 12:39 PM
Hi friends,
I have been surprised to see that some authorities, including
worldbirdnames, have accepted the split of the Eastern Cattle Egret from the
taxon found in the rest of the world. Given the way that Cattle Egrets have
spread so widely around the world in such a relatively short time, I find it
hard to believe that gene flow could have been interrupted long enoguh for a
new species to emerge.
I would welcome any thoughts.
Dr John Penhallurick
86 Bingley Cres
Fraser A.C.T. 2615
Australia
email:
Phone: Home (612) 62585428
Mobile:0408585426
sunt lacrimae rerum et mentem mortalia tangunt Aeneid Book 1,line 462 "The
world is a world of tears, and the burdens of mortality touch the heart."
Magna est veritas et praevilabit Vulgate, Book of Edras
Si vis pacem para bellum Publius Flavius Vegetius Renatus
<http://en.wikipedia.org/wiki/Publius_Flavius_Vegetius_Renatus> 's De Re
<http://en.wikipedia.org/wiki/De_Re_Militari> Militari, book 3
Please visit my website:http://www.worldbirdinfo.net
Please also visit my blog at
http://jpenhall.wordpress.com/2011/04/02/proof-that-there-is-not-a-scrap-of-
evidence-in-favour-of-the-ipccs-attack-on-carbon-dioxide/
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