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ORNITOLOGIA NEOTROPICAL 15: 139–141, 2003 © The Neotropical Ornithological Society

FIRST DOCUMENTED RECORD OF THE BROWN-AND-YELLOW MARSHBIRD (PSEUDOLEISTES VIRESCENS) FOR PARAGUAY, WITH COMMENTS ON ITS SYMPATRY WITH THE YELLOW- RUMPED MARSHBIRD (P. GUIRAHURO) IN ARGENTINA AND PARAGUAY

Rosendo M. Fraga1, Mariano Codesido1, Hernán Povedano2, Alejandro Jurado3 & Rodrigo Zárate1

1Asociación Guyrá Paraguay, Cte. Franco 381 c/ L. Prieto, Asunción, Paraguay. E-mail: [email protected] 2Centro de Investigaciones Científicas y TTP-CONICET, Materi y España, (3105) Diamante, Entre Ríos, Argentina. 3Calle 10 Nº 1285, 3 A, (1900) La Plata, Argentina.

Primer registro documentado del Dragón (Pseudoleistes virescens) para Paraguay, con comentarios sobre su simpatría con el Guirahuró (P. guirahuro) en Argentina y Paraguay. Key words: Pseudoleistes virescens, P. guirahuro, Paraguay, Argentina, Brown-and-yellow Marshbird, Yellow- rumped Marshbird.

Some checklists and reference books (e.g., observed and filmed a small flock of 11 indi- Narosky & Yzurieta 1987, the map in Ridgely viduals in the site known as Isla Ro´y, Depar- & Tudor 1989) include Paraguay in the range tamento Ñeembucú, Paraguay (27o13’24”S, of Brown-and-yellow Marshbirds (Pseudoleistes 57o53’22”W). A copy of the film was depos- virescens), but other sources do not (e.g., Short ited in the archives of Guyrá Paraguay, the 1975, Olrog 1979). After reviewing the avail- ornithological society of that country. The able evidence, Hayes (1995) placed this observation site is located 15 km north of the in the list of hypothetical Paraguayan . Río Paraná, the international border between The reasons were simple: there were no Argentina (Corrientes province) and Para- specimens of the species collected in Para- guay. The Brown-and-yellow Marshbirds were guay, or Paraguayan records properly docu- found in a marshy pasture, grazed by cattle mented with photographs, films or tape and horses. We showed the to a local recordings. peasant, who recognized the birds as different On 6 March 2002, while conducting an from the Yellow-rumped Marshbird (Pseudo- ornithological survey, we obtained a docu- leistes guirahuro), giving it a different vernacular mented record of the presence of Brown- Guaraní name (“guyrá-u-choré” vs “guyrá-u- and-yellow Marshbirds in Paraguay. We ro”). Both species differ in size and colora-

139 FRAGA ET AL. tion, particularly in the diagnostic rump color, Fe, eastern Chaco and Formosa. Our data brown in the Brown-and-yellow Marshbird, agrees closely with this last author. yellow in the other species. The vocalizations The unique sight record of the Yellow- of both marshbirds are distinctive and easy to rumped Marshbird for Buenos Aires is recognize. undocumented and questionable (Hellmayr Throughout eastern Paraguay the Yellow- 1937, Narosky & Di Giacomo 1993). We rumped Marshbird is a common and wide- found two sight records of the Yellow- spread (Hayes 1995, pers. observ.), rumped Marshbird for Entre Ríos (one pub- whereas its congeneric relative is at best rare lished: Serié & Smyth 1923), and no collected and local. The Asociación Guyrá Paraguay specimens (Camperi 1989). Throughout this keeps a database with more than 40,000 bird area virescens is a common species in marshes records for hundreds of localities in the coun- and grasslands (pers. observ.). In Corrientes try, and up to now the database contained north of the 29º30’S, the Yellow-rumped only four undocumented observations of the Marshbird is regularly present; at Estancia Brown-and-yellow Marshbird. These previous San Juan Poriahú (27º42’S, 57º11’W), 20 km observations were in the Bajo Chaco, Central south of the Paraná river, both marshbirds Paraguay and Ñeembucú geographical are common and breed in sympatry (Fraga regions (as defined in Hayes 1995). The fact 2001). Further north, on the Argentinian Isla that the Brown-and-yellow Marshbird has a Apipé Grande in the Paraná river, both spe- vernacular Paraguayan name suggests that it is cies occur, but the Brown-and-yellow Marsh- not accidental in the country, but this needs bird is rare (R. Fraga & A. Bodrati pers. verification. observ.); in the adjacent Isla Yacyretá in Para- Besides Paraguay, both marshbird species guay, only the Yellow-rumped Marshbird has have been reported in sympatry in southern been so far reported (Lowen et al. 1996, pers. Brazil (Rio Grande do Sul and Santa Catar- observ.). ina), eastern Uruguay, and eastern Argentina Distributional data from Río Grande do (Belton 1985, Sick 1993, Azpiroz 1997). We Sul, Brazil (Belton 1985), suggest a habitat briefly discuss here the Argentinian area of segregation of both marshbirds along an alti- sympatry, based on our field records (includ- tudinal gradient (sea level to 1300 m): the Yel- ing tape recordings) and literature searchs, low-rumped Marshbird was found mostly including specimen labels in museums (com- near wetlands in hilly country, and the other piled by Camperi 1989). The maps for both species in wet meadows and marshes in the Pseudoleistes species in Ridgely & Tudor (1989) lowlands. A similar situation may exist in Uru- suggest an extensive area of sympatry in east- guay (A. Azpiroz pers. comm.). However, ern Argentina (Corrientes, Entre Ríos and similar topographical gradients do not occur northeastern Buenos Aires provinces). The in northeastern Argentina and southern Para- corresponding maps in Jaramillo & Burke guay. In the area of sympatry in Corrientes, (1999) show a more reduced overlap, as Bue- for instance, the altitudinal range is only 30 to nos Aires and most of Entre Ríos provinces 80 m (Carnevali 1994). At Estancia San Juan are excluded from the range of the Yellow- Poriahú, both marshbirds foraged, roosted rumped Marshbird. The maps in De la Peña and nested in the same marshes (Fraga 2001). (1999) go even further, showing the two spe- As Sick (1993) noticed, however, the two spe- cies overlapping only in the northern half of cies usually did not associate. A detailed study Corrientes and southern Misiones, and west of their ecological relationships in sympatry of the Paraná river locally in northern Santa would be rewarding (Short 1975).

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ACKNOWLEDGMENTS Hellmayr, C. E. 1937. Catalogue of the birds of the Americas and the adjacent islands. Volume 12. Our survey was included in a project con- Field Museum of Natural History, Chicago, Illi- vened beween Asociación Guyrá Paraguay nois. and Entidad Binacional Yacyretá. We Jaramillo, A., & P. Burke. 1999. New World black- birds. The . Princeton Univ. Press, Prin- acknowledge the support given by Drs. M. ceton, New Jersey. Cubas and D. Zamudio from the last institu- Lowen, J. C., L. Bartrina, R. P. Clay, & J. A. Tobias. tion, and to A. González and A. Stroessner 1996. Biological surveys and conservation pri- for hospitality in Ñeembucú. F. Hayes and A. orities in eastern Paraguay. Cambridge Bird Azpiroz reviewed the manuscript. Conservation Publications, Cambridge, UK. Narosky, T., & D. Yzurieta. 1987. Guía de campo REFERENCES para las aves de Argentina y Uruguay. Asoci- ación Ornitológica del Plata y Vásquez Mazzini Azpiroz, A. B. 1997. Aves del Uruguay. Lista, esta- Editores, Buenos Aires, Argentina. tus y distribución. PROBIDES, Rocha, Uru- Narosky, T., & A. G. Di Giácomo. 1993 Las aves de guay. la provincia de Buenos Aires: distribución y Belton, W. 1985 Birds of Rio Grande do Sul, Brazil. estatus. Asociación Ornitológica del Plata, Part 2. Formicariidae through Corvidae. Bull. Vásquez Mazzini Editores and Literature of Am. Mus. Nat. Hist. 180: 1–242. Latin America, Buenos Aires, Argentina. Camperi, A. R. 1989. Localidades nuevas para Olrog, C. C. 1979. Nueva lista de la avifauna argen- ictéridos de la Argentina (Aves, Passeriformes). tina. Opera Lilloana 27, Instituto M. Lillo, Neotropica 35: 91–94. Tucumán, Argentina. Carnevali, R. 1994. Fitogeografía de la provincia de Ridgely, R. S., & G. Tudor. 1989. The birds of Corrientes. Gobierno de la Provincia de Corri- South America. Volume 1. The Oscine passe- entes and Instituto Nacional de Tecnología rines. Univ. of Texas Press, Austin, Texas. Agropecuaria, Corrientes, Argentina. Serié, P., & C. H. Smyth. 1923. Notas sobre aves de De la Peña, M. R. 1999. Aves argentinas. Lista y Santa Elena (E. Ríos). Hornero 3: 37–55. distribución. Literature of Latin America, Bue- Short. L. L. 1975. A zoogeographic analysis of the nos Aires, Argentina. South American chaco avifauna. Bull. Am. Fraga, R. M. 2001. The avifauna of Estancia San Mus. Nat. Hist. 154: 163–352. Juan Poriahú, Iberá Marshes, Argentina. Cot- Sick, H. 1993. Birds in Brazil. A natural history. inga 16: 81–86. Princeton Univ. Press, Princeton, New Jersey. Hayes, F. E. 1995. Status, distribution and biogeog- raphy of the birds of Paraguay. Monogr. Field Ornithol. 1: 1–224. Accepted 12 May 2003.

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