“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.

2 comments to “Eastern” Cattle Egret, Bubulcus coromandus

  • Kumar Ghorpade

    Thanks Jeff.  Do please note in addition . . . 1)  The RIPLEY GUIDE (Vol. 2: 58) suggests that B. ibis “Could also occur in NW of region.” 2)  Whistler’s (posthumous) fine regional, 5-part faunistic paper on Afghanistan (see JBNHS 45: 462-485) makes NO mention of a Cattle Egret record from that country so that’s that. Krys’ best (very inclusive, if not critical like Pamela’s) maps (2000: Plate 5) can be viewed for B. coromandus (as “ibis” !) recorded range.  I include Baluchistan and Afghanistan in my recognised Oriental region, also most of the Tibetan Plateau, and Burma at least west of the Irrawaddy river.  No regional monograph has been as inclusive and have omitted Burma and Afghanistan following previous authors and ignored biogeographical findings.  Like New Guinea and nearby islands are accepted as Oriental and NOT Australian in affinity. 3)   I have cautioned against a lackadaisical attitude to “mobility” and the power of flight of birds.  Recent findings have also given support to my own belief that migratory species do NOT have any chance of interbreeding in their winter haunts and remain reproductively isolated.  Many Motacilla flava “subspecies” I believe are good species ! 4)  There is a wonderful paper on speciation in birds written by Salim Ali’s “Guru” Erwin Stresemann and J. Arnold (1949; JBNHS 48: 428-443) which should clear all doubts of amateurs and confused professionals (there are several !!) about this quandary.  READ IT please. 5)  The Baluch-Afghan desert corridor is a little known geographical barrier and I am now analysing species identities of our Afrotropical source species (and races) for their true identities in our subcontinent.  Ticehurst highlighted what he called the “Great Palaearctic Desert” extending from the western Sahara to Mongolia and one of my favourite, classic, paper is of the great Allan Hume on the “Birds of Sindh” in his Stray Feathers (1: 44-49. 91-289, map) that I think is a model for serious bird-watchers to try and emulate and prepare more accurate regional faunas like the dream, hope, of the legendary Gilbert White of England !        Small is beautiful, friends, and large countries or geographical areas are amenable, possible only to a  GENERAL documentation, even if attempted by a group of collaborators.  Amen. 

    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.

  • "Jeff Davies"

    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.