) . tion of the genus plex of Great Skua’ forms.examined In in the thefirst lightingplace, on ofspecimensI supportDevillers’s of the (1977)recogni­ elucidation of the com­ is thus primarily a statesouthern whichhemisphere distinguishesbreeding genus while is no barring in the juvenalis plumageoften of synonymized,any plumages are ofextensively the three speciesbarred of below, whereas there The purpose of this paper is to show cause why a checklist of Catharacta skua Catharacta and, indeed, the Charadriiformes, since they alone possess it.may be properly corariusplaced as the Stercorariinae, and the elaboration Charadriiformes as far as I barring,am aware), is whichclearly a deriveddoes characternot occur elsewhere in the Laridae (or the South African birds should contain the following entries by report­ derived character of statethe rhamphothecawhich defines of themthe bill withinmay thebe convenientlyLaridae, noted as a subsequent designation by Reichenbach, VOL. XI, PART [Price 2 1 0 2 d R l,5 0 e t THE is purely Holarctic in its breeding season. The two genera (P.F.I.A.O., University of Cape Town, Rondebosch) a d Brunnich, OCCURRING IN SOUTH AFRICAN WATERS Subfamily STERCORARIINAE G. R. Gray ( r 18 18 e CATHARACTA nett] h s Brunnich, 1764. i l Catharacta, b Genus CATHARACTA Brunnich u P Catharacta Family LARIDAE Vigors e h Ornithologia Borealis, t y R. K. BROOKE b Stercorarius TAXONOMY d mainly on the grounds that the juvenal e t preserved in South African museums SKUAS (AVES: LARIDAE) n a r by Stercorarius, g e c n e from c i l r e Catharacta d 1764, p. 32. n with which Catharacta. Catharacta u y a IS S U E D w e Nat., t a form. Juvenal G t 1852, p. v, 1st e Catharacta n i Type, M A Y , b a S Ster­ y 1978 by b d e c u d o r p e R ) . phere and thusis the couldonly southernmost form whicheasily regularlyestablish visits the a northernnorthern hemis­ offshoot. Stercorarius maccormicki the nuchal feathers in the adult nuptial plumage, and the development of distinctive and elaborate pale shaft-streaks to maccormicki Stercorarius antarcticus CATHARACTA MACCORMICKI (Saunders) South Polar Skua. Atlantic. north Pacific, secondarily to northern Indian Ocean. Also North and that the Devillersjuvenal statesplumages that someare likewiseindividuals verylook similar.very likeBut hemisphere.C. This latterin the southernis hemisphere and that one form occurs in the northern waters. 1893, p. xii: Possession Island, Victoria Land, Antarctica. with which of the three havesouthern speciessubspecies it is supposedlybreeding conspecific.in the south, but it is not at all clear Catharacta antarctica madagascariensis antarctica madagascariensis Catharacta Non-breeders wander widelyBreeds in onall southernthe seas. AntarcticCATHARACTA Peninsula ANTARCTICAand all subantarctic(Lesson) Subantarcticislands. Skua. 296 species. Tristan island groups. Non-breeding range probably that of the Generum Avium, Presumed to be an occasional visitor passing through South African brown phase of sight records do not distinguish betweenExtra-limitally this species in andAfrican the coastaldark waters north to at least Annobon Island in the west, and, apparently, to Egypt in Presentthe east, butthroughout eastern the year but commonest April to September. 2 1912, p. 212: New Zealand seas. New synonym. 1 Breeds Antarctica and South Shetlands: non-breeding visitor to Two obtained off Cape St Francis, Cape Province, 16 May, 1963. Catharacta antarctica lonnbergi 0 Breeding range that of the species except for the Falkland and Devillers (1977) has shown that three species of Regular non-breeding visitor to South African coastal waters. 2 d e t a d ( r and e h s i l C.maccormicki. The Catharada sktias in S.A. waters b vol. ii, 1857, p. 207: Madagascar. u C.chilensis P e h t a. y b Saunders, d C.skua, madagascariensis e (Bonaparte (1857)) share with t n a r g Mathews, e which is com m only assumed to c n e c i Bull.Brit.Orn.Club, l (Bonaparte) r e d n Bonaparte, u Novit.Zool., y a w e t Catharacta a G C.maccormicki C.a.antarctica t e vol. xviii, n Conspectus i vol. iii, b a S C.skua occur y b d e c u d o r p e R ) . Heads of the two 2 1 Note much smaller size of bill and difference in mandibular sculpture 0 2 d e t a A. in d ( B. C.maccormicki Catharacta antarctica madagascariensis r e Catharacta maccormicki h s i l Catharacta b u P e h t compared with by R. K. Brooke y b spp. occurring in southern African waters. d e t FIG. I n a r g (Saunders). e c n C.a.madagascariensis. e c i l 297 r e d n (Bonaparte). u y a w e t a G t e n i b a S y b d e c u d o r p e R 298 The Catharacta skuas in S.A. waters Swales (1965) considers C.skua as derived from C.chilensis, while Hagen (1952) regards his C.a.hamiltoni as hardly separable from it. We do not currently have the information to allow us to say what southern Catharacta is most closely related to C.skua, and to link it hopefully to one of them is to pretend to a knowledge which we do not possess. It also makes the biological species concept even more subjective than it need be. I therefore regard C.skua, the Bonxie or Great Skua, as a monotypic species restricted to the north-east North Atlantic in the breeding season. In the southern hemisphere there are two monotypic species: the Chilean Skua C.chilensis breeding on both coasts of southern South America, and the South Polar Skua C.maccormicki already mentioned, and the Subantarctic Skua C.antarctica with three subspecies: nominate C.antarctica (Lesson, 1831), breeding in the Falkland Islands and Patagonia, C.a.hamiltoni Hagen, 1952, breeding in the Tristan da Cunha Group, including Gough Island, and C.a.madagascariensis (Bonaparte, 1857) breeding on all other sub-antarctic islands, in­ cluding the South Shetlands, and the tip of the Antarctic Peninsula, where it is sympatric with C.maccormicki at both places. The type-locality of C.maccormicki is Possession Island (one of ) . several in the southern seas) but its exact whereabouts is difficult 2 1 to establish. Saunders (1893) added Victoria Land at 71° 14' S., 0 2 171° 15' W. This places it in the Ross Sea some 20° of longitude d e t a east of Victoria Land at that latitude. Watson et al. (1971) give d ( the coordinates of this Possession Island as 71° 27' S., 171° 08' E., r e h whereas the U.S. Board on Geographic Names in their Gazetteer No. s i l 14, Antarctica, ed. iii, 1969, gives them as 71° 52' S., 171° 12' E. b u P Both of these positions would make Possession Island an offshore e h island of Victoria Land. We may assume a lapsus calami in Saunders t y (1893) whereby he wrote ‘W .’ instead of ‘E’. b d e Bonaparte’s (1857) account of the skuas seems to have been very t n a seldom consulted. Saunders (1876) alluded to it, though without r g full consideration of its contents, and nobody else seems to have con­ e c n sidered it at all. Bonaparte recognized two genera in his Lestridinae e c i l (= Stercorariinae), Stercorarius Vieillot nec Brisson (= Catharacta r e Briinnich) and Lestris Illiger (= Stercorarius Brisson). At this point, d n it should be remarked that Saunders (1876) is a reliable guide to the u y a nomenclatural tangles of last century. In Catharacta Bonaparte w e recognized two species, catarractes L., 1766, ( = skua Briinnich, t a 1764) and antarcticus Lesson. Under the latter he recognized two G t e varieties as follow s:- n i b “ a. madagascariensis. Bp.Mus.Paris, a Berniero, ex Madagascar. a S y Rostro elongatd, robusto. b d e c u d o r p e R by R. K. Brooke 299 b. chilensis, Bp.Mus.Berol.ex Am.m. Rostro vix breviore quam in europaeo, potius graciliore quam robustiore.". The name chilensis has been in universal use ever since Saunders (1876) resurrected and endorsed it, but madagascariensis has been largely ignored. However, the proposal clearly mentions the large, heavy bill which distinguished the subspecies lonnbergi Mathews (1912) of Hamilton’s (1934) and Devillers’s (1977) revisions and accepted by virtually all workers, normally as a race of either skua or antarctica. The only form of Catharacta recorded from Madagascar in Milon et al. (1973) is C.a.intercedens Mathews, 1913 (proposed in a species C.lonnbergi), which was placed as a synonym of the race lonnbergi by Hamilton (1934). This synonymy is widely accepted. Nonetheless, the question should be reinvestigated since it would seem that true lonnbergi from New Zealand’s subantarctic islands has elongated golden shafts in nuptial plumage (Falla (1937); Serventy in Crawford (1952)), whereas populations breeding on Kerguelen (the type-locality of intercedens), the Crozets and the Prince Edward Group only show this as an aberration. C.a.clarkei Mathews, 1912: South Orkneys, would also be a synonym of a re­ stricted madagascariensis, which may also be smaller on average ) . than New Zealand lonnbergi. Since the name lonnbergi is that of a 2 1 subspecies and one virtually never regarded as a species I see no 0 2 reason to seek its conservation at the expense of its senior subjective d e t synonym , madagascariensis, particularly as the synonymy is not a d ( fully established. Most subspecies are of interest only to taxonomists r e h who can readily appreciate the requirements of the Law of Priority.