|WI - Cormorant Research Group||Species fact-sheets and accounts||last updated on 19-09-2001|
Relationships of the Cormorants
modified after Johnsgard P. A. - 1993
Cormorants, Darters and Pelicans of the World.
Smithsonian Institution Press, Washington and London.
In his taxonomic treatment of the cormorants, Ogilvie-Grant (1898) recognized only a single genus Phalacrocorax, and his linear sequence of the 36 species was seemingly one of convenience, based on the construction of his identification key. Thus, little value is gained by discussing it in detail, and instead one may pass on to the widely adopted classification by Peters (1931). In addition to Phalacrocorax, Peters accepted Nannopterum as a monotypic genus for the flightIess cormorant, and generically separated four species of very small, short-bilIed cormorants as Halietor. Although accepting a considerable number of now-discarded subspecies, he admitted a total of only 30 species in the entire family.
Van Tets (1976a) provided what might well be regarded as the first biologically meaningful classification of the cormorants as part of a zoogeographic analysis of the family's probable origins. Van Tets subdivided the family into two approximately equal genera, Phalacrocorax ("cormorants") and Leucocarbo ("shags"), with a total of 34 extant species exclusive of the extinct Pallas' cormorant, which he didn't take into account. Van Tets offered a number of morphological and biological criteria for his generic separation. He furthermore divided each of these two genera into a total of five subgenera, the shags consisting of two subgenera (Leucocarbo and Stictocarbo), and the cormorants consisting of three (Phalacrocorax, Hypoleucus, and Microcarbo, with the last-named subgenus corresponding to Peters's genus Halietor.
The most recent and by far the most fully documented of the available classifications of the Phalacrocoracidae is that of Siegel-Causey (1988), which is based on a cladistic analysis using quantitative osteological characters. His resulting proposed classìfication accepts 37 species and bears a considerable number of similaritìes to that of van Tets. However, instead of dividing the family into two genera, he accepts two subfamilies, the overall composìtions of which are very similar, and also recognízes a total of nine genera. In several cases these genera correspond to the subgenera of van Tets, but the large subgenus Leucocarbo as proposed by van Tets was subdivided by Siegel-Causey into five genera.
The revision of the Phalacrocoracidae by Dorst and Mougin (1979) may be thought of as a compressed variation on that proposed by van Tets. These authors reduced van Tets's proposed genus Leucocarbo to a subgenus and accepted only 29 species, all within Phalacrocorax. Sibley and Monroe's recent (1990) taxononomy of the cormorants accepted 38 species, all of which they likewise included within the single genus Phalacrocorax. Sibley and Monroe further reported that Sibley's DNA hybridization results do not support a "diversity of relationships" such as the two subfamilies and nine genera proposed by Siegel-Causey, although they did adopt his suggested sequence of species.
|Van Tets (1976)||Dorst and Mougin (1979)||Siegel-Causey (1988)|
(1) Subgeneric allocation uncertain; possibly part of Stictocarbo.
(2) Identified as component members of superspecies groups.
(3) Considered as possibly conspecific with pygmaeus.
(4) Exclusive of perspicillatus, which was not considered by van Tets. Comments in a recent handbook (Marchant & Higgins, 1990) indicate that van Tets now admits five genera in two subfamilies (Phalacrocorax and Microcarbo in the Phalacrocoracinae, plus Nannopterum, Stictocarbo, and Leucocarbo in the Leucocarboninae). His genus Phalacrocorax thus encompasses Siegel-Causey's Hypoleucus, and his genus Nannopterum includes most of the forms separated by Siegel-Causey as Compsohalieus,Notocarbo, Nesocarbo, and Euleucocarbo. The remaining three genera correspond to van Tetss prior subgenera as listed above. Sibley and Monroe (1990) accepted 38 species, all included in Phalacrocorax.
(5) This list does not include P. kenyoni a new species described by Siegel-Causey in 1991.
Dorst J. & Mougin J. L . 1979. Order Pelecaniformes. Pp. 155-93, in: E. Mayr and G. W. Cottrell (eds.), Check List of Birds of the World, vol. L 2d ed. Museum of Comp. Zool., Cambridge, Mass.
Marchant S. & Higgins P. H. (eds.). 1990. Handbook of Australian, New Zealand and Antarctic birds. Vol. l. Oxford Univ. Press, Melbourne.
Ogilvie-Grant W.R. 1898. Steganopodes. pp. 329-484, in: Catalogue f the birds in the british Museum, vol. 26. British Museum (Nat. Hist.), London.
Peters J. P. 1931. Check-list of the birds of the world. Vol. I. Harvard Univ. Press, Cambridge.
Sibley C. G. & Monroe B. L. Jr. 1990. Distribution and taxonomy of birds of the world. Yale Univ. Press, New Flaven.
Siegel-Causey D. 1988. Phylogeny of the Phalacrocoracidae. Condor, 90(4): 885-905.
Siegel-Causey D. 1991. Systematics and biogeography of north Pacific shags, with a description of a new species. Occasional papers of the Museum of Natural History (Lawrence, Kansas: The University of Kansas), 140 : 1-17.
van Tets C. F. 1976. Australasia and the origin of shags and cormorants, Phalacrocoracidae. Pp. 121-124, in: Proc. 16th Inter. Ornith. Congr., Canberra, Australia, 1974.
Page create on
by S. Volponi