& J.M. CardosodaSilva D.C. Oren 147 Bull.B.O.C. 1991 111(3) A new subspecies of Xiphocolaptes major (Vieillot) from Argentina & byJose Maria Cardoso da Silva David C. Oren Received29November1990 Xiphocolaptes major (Vieillot) is a large dendrocolaptid (>90g) with a distribution that includes Brazil in Mato Grosso and Mato Grosso do Sul, northernand eastern Bolivia, and Argentina fromJujuy to Cordoba and Santa Fe (Meyer de Schauensee 1970). There are three recognised subspecies (Peters 1951): X. m. remoratus Pinto, known only from the type locality, Fazenda Arica-mirim, on the banks ofthe lower rio Arica, Mato Grosso; X. m. castaneus Ridgway of Bolivia, southwestern Mato Grosso and northern Mato Grosso do Sul in Brazil, and northwestern Argentina in the Provinces ofJujuy and Salta, where it intergrades with the nominate subspecies; and X. m. major (Vieillot), from Paraguay and Argentina in Chaco, Cordoba, Estero, Formosa, Santa Fe and Santiago (Fig. 1). X.m.remoratusissimilartothenominatesubspecies,having,however, "thepileumandmantlelesslight,brownisholivaceous(insteadofgreyish brown), thethroatwhitishonlyonthemedianportion, andnotaslightas theother, and the underparts less tinged with rusty" (Pinto 1945). X. m. castaneusdiffersfromX.m.majorbythe"pileumdecidedlydarker,russet brown or dusky brown (instead ofbuffy brown); chestnut ofupper parts on average deeper, and lower surface somewhat darker, more rusty cinnamon" (Hellmayr 1925). While reviewing specimens of X. major deposited at the American Museum of Natural History, New York, we found that a series of six specimens from the Province of Tucuman, Argentina, possess much lighter plumage colouration than specimens from nearby localities attributed to the nominate race. We propose that this population be known as Xiphocolaptesmajorestebani subsp. nov. Holotype. American Museum of Natural History, AMNH 524675, adult male collected at Tapia (26°36'S, 65°18W), Tucuman, Agentina. Collected by L. Dinelli on 14 Sep 1902. Field Number 1847. Diagnosis. Colours in capitals with numbers in parentheses refer to Smithe (1975, 1981). Similar to X. m. major (Vieillot), differing by the plumage in general being much paler, with crown between Light Drab (119C) and Dark Drab (119B), instead of Antique Brown (37); back between Brussels Brown (121B) and Mikado Brown (121C), instead of RawSienna(136);feathersofthebreastandbellywithcentresClayColor (26) and borders Cinnamon (123A), instead of Raw Umber (123) and AntiqueBrown(37), respectively;tailRusset(34),insteadofWarmSepia (221A). jf.M.CardosodaSilva&D.C.Oren 148 Bull.B.O.C. 1991 111(3) Figure 1. Distribution of the subspecies of Xiphocolaptes major. =remoratus; A= castaneus; •=major; =estebani; T=intergradesbetweencastaneusandmajor. Measurements ofthe holotype (in mm). Wing ('flat'), 155.0; tail, 109.5; bill (from insertiontotip), 59.5; tarsus, 30.0. AMNH Paratypes.Threemales, 524676,524677and524678,collected by L. DineAllMiNonH24 Oct 1901 (first two) and 19 Sep 1902 (last); and two females, 524679 collected by L. Dinelli on 24 Oct 1901, and AMNH 524682 collectedby S. Venturion 8Jul 1900, allfromthetype locality. Distribution. Known from the type locality and Tafi Viejo, Prov. Tucuman, Argentina(apudEsteban 1948), andthe surrounding region. Etymology. The subspecific name honours Argentine ornithologist Juan G. Esteban, who was the first to do a complete revision of the Dendrocolaptidaeofhis country(Esteban 1948). Comments. X. m. castaneus has plumage which is much more reddish thanX. m.majorandX.m.estebani.X.m.remoratus,basedontheoriginal description, is darker than the nominate subspecies (Pinto 1945) and, consequently, thanX. m. estebani. The paratypes show uniformity in the diagnostic characters. Two (AMNH females 524679 and 524682) have very indistinct transverse black bars on the abdomen, these being almost absent in 524682. The other specimens all have well-marked abdominal bars. Comparative measurements of X. m. major, X. m. castaneus and the newly proposed subspecies are presented in Table 1. The observed differences in measurementswerenotstatisticallysignificantforanycharacter,perhaps inpartbecauseofthe small sample sizes. Asinglemale(AMNH 524680), alsolabelledfromthetypelocalityand AMNH supposedly collected together with female paratype 524682 by Venturi, is indistinguishable from the nominate subspecies, while another male (AMNH 524681), collected by the same Venturi, labelled 5 J.M. CardosodaSilva&D. C.Oren 149 Bnll.B.O.CA99\ 111(3) TABLE 1 Comparative measurements (in mm) of three races of Xiphocolaptes major. For samplesof5 ormore, the firstnumberisthemean, followed bythestandarddeviation in parentheses Wing Tail Bill Tarsus X.m.major 7<$<S 150.8(3.8) 107.4(5.8) 56.7(1.1) 30.3(3.1) 12 11 148.7(4.2) 110.0(3.6) 57.5(1.9) 30.3(2.2) X.m.castaneus — i -; 142.0 106.0 30.5 211 141.0,142.0 103.0(n=l) 52.0,55.0 28.0,30.5 X.m.estebani 5cTc? 153.2(4.0) 109.9(5.4) 58.2(1.1) 30.7(1.9) 222 149.0,155.0 109.0(w=l) 59.0,61.5 30.5,34.5 from "Ocampo, Chaco" (Villa Ocampo is, in fact, in Santa Fe Province, according to Paynter 1985) is typical of estebani. These two specimen labels most certainly were inadvertently exchanged. S. Venturi was an ItalianresidentinArgentina,whencehesentabirdskincollectionof111 specimens for sale to the Rothschild Museum in Tring, England. The Venturi collection was made between 1898 and 1906 at diverse localities in the Provinces of Buenos Aires, Santa Fe, Tucuman and Jujuy (for details, see Hartert & Venturi 1908). Whether the accidental label exchangewas madebyVenturi orinTring is unclear. Acknowledgements WearegratefultothestaffoftheornithologysectionoftheAmericanMuseumofNatural History, especially Mary LeCroy, George Barrowclough, and Francois Vuilleumier, for numerouscourtesiesextendedduringourvisittothecollectionsundertheircare. References: Esteban,J.G. 1948.Contribucionalconocimientodelosdendrocolaptidosargentinos.^lcta Zool.Lilloana5:325^-36. Hartert, E. &Venturi, S. 1909. NotessurlesoiseauxdelaRepubliqueArgentine. Novit. Zool. 16:11-267. Hellmavr,C.H. 1925.CatalogueofbirdsoftheAmericasandtheadjacentislands.PartIV. Publ.FieldMus.Nat.Hist.,Zool.Ser. 13. MeyerdeSchauensee,R. 1970.AGuidetotheBirdsofSouthAmerica. Livingston. Paynter, R. A., Jr. 1985. Ornithological GazetteerofArgentina. Museum ofComparative PeterZs,ooJl.oLg.>1r,9H5a1r.vCahredc.k-listofBirdsoftheWorld.Vol.7.MuseumofComparativeZoology, Harvard. Pinto, O.M. O. 1945. DuasformasnovasnogeneroXiphocolaptes Pap. Avuls.Dep.Zool. . S.Paulo5: 135-140. Smithe, F.B. 1975(Part 1); 1981 (Part2).Naturalist'sColorGuide. Am. Mus. Nat. Hist., New York. Address:Jose M. Cardoso de Silva & David C. Oren, Depto. Zoologia, Museu Paraense EmilioGoeldi,C.P. 399,66.040Belem,PA,Brazil. ©BritishOrnithologists'Club 1991