SummaryBased on 21,518 km of road surveys, the Argentinian range of the endangered Saffron-cowled Blackbird Xanthopsar flavus now seems confined to two small and disjunct areas in Corrientes and Entre Rios provinces, north-east Argentina. In Corrientes the species inhabits natural pastures and rice-fields; in Entre Rios agropastoral land. Estimates based on numbers of localities and flock sizes suggest a Saffron-cowled Blackbird population of 500-1,000 individuals. This blackbird is highly gregarious. Mean flock size (n = 30, non-breeding period) was 31.9 birds (range: 6-102), and was significantly larger in Entre Rios. In Corrientes foraging blackbird flocks associated mostly with the Black-and-White Monjita Xolmis dominicana, in Entre Rios with the Brown-and-Yellow Marshbird Pseudoleistes virescens. Nesting in both provinces was colonial, with up to 24 nests in a 0.43 ha plot. Nests were built in native and introduced herbaceous plants. The Shiny Cowbird Molothrus bonariensis parasitized 29.2% of the nests in one colony; its eggs and chicks are larger than those of the host. Plausible reasons for the species's extinction or decline at a local level are drainage of wetlands (south-west Buenos Aires Province) and the replacement of pastures with pine and eucalypt plantations in Corrientes. General threats include trapping for the pet trade and increased cowbird parasitism. Flocks below a minimum size may not be viable. An urgent measure of protection would be the fencing and preservation of traditional colony sites.En base a 21.518 km de censos de rutas parece que la distribution actual del amenazado Tordo Amarillo o Dragon Xanthopsar flavus en Argentina esta limitada a dos pequenas areas disyuntas en las provincias de Corrientes y Entre Rios. En Corrientes la especie se encuentra en pasturas naturales y arroceras, mientras que en Entre Rios usa campos agrfcola-ganaderos. Una estimation basada en el numero de localidades y tamanos de bandadas indicaria una poblacion total de 500 a 1.000 individuos. El tamano promedio de bando (n = 30, periodo no reproductive) fue 31,9 individuos (rango 6-102) y es significativamente mayor en Entre Rios. En Corrientes las bandadas se asocian principalmente con la Monjita Dominica Xolmis dominicana, y en Entre Rios con el Pecho Amarillo Pseudoleistes virescens. La nidificacion fue colonial en ambas provincias, con una densidad de hasta 24 nidos en 0,43 ha. Los nidos se construyeron en plantas herbaceas nativas y exoticas. El Tordo Renegrido Molothrus bonariensis parasito 29,4 % de los nidos de una colonia, siendo sus huevos y polios significativamente mayores. Posibles razones para la extincion y declination a nivel local de la especie serian el drenaje de humedales (SO de Buenos Aires) y el reemplazo de pasturas por bosques implantados de pinos y eucaliptos (Corrientes). Las amenazas a nivel generates incluyen la captura para el Rosendo M. Fraga, Herndn Casanas and German Pugnali 256 comercio de aves de jaula, y un mayor parasitismo de cr-ia. Una medida urgente de protection de l...

Estado y conservación del cauquén colorado Chloephaga rubidiceps Sclater (Aves,

The coast of the Buenos Aires province, Argentina, includes a remarkable diversity of habitats and is used by more than fifteen Nearctic shorebird species during the austral summer months. We evaluated non-breeding shorebird distribution and abundance patterns along the Buenos Aires coastal zone and determined shorebird use of different coastal landscapes. Surveys were conducted in December 2000, and January and February 2001, using line-transect methods. The data were classified based on five previously defined coastal landscapes. Fifty four localities were surveyed covering 93 kilometers of coastline. A total of 44 waterbird species corresponding to 13 families were recorded. Shorebirds (Scolopacidae, Charadriidae, Haematopodidae and Recurvirostridae) accounted for approximately 45% of recorded waterbirds, including 14 nearctic species. Shorebird species recorded per locality varied from one to eleven, with 61% of the localities having one to four species. The most common were the American Oystercatcher ( Haematopus palliatus ), White-rumped Sandpiper ( Calidris fuscicollis ), Two-banded Plover ( Charadrius falklandicus ), American Golden-Plover ( Pluvialis dominica ) and the Sanderling ( Calidris alba ). Shorebird species richness and abundance varied significantly among coastal landscapes, with the highest values recorded in estuarine saltmarshes of Bahía Samborombón and Bahía Blanca. Among marine landscapes, the highest abundance and number of species were recorded in sandy beaches with "restinga" patches. This study confirms that shorebirds are an important component of the birdlife in the Buenos Aires coastal zone during the austral summer months, and that their distribution is not homogeneous along the coast, with species richness and abundances varying among localities depending on coastal landscapes.

, but so far, there is no formally published evidence of its presence in the country. During our ornithological studies in the provinces of Jujuy, Salta, and San Juan we recorded the species in numerous localities, confirming pre-existing speculations. In this contribution we describe these records, extending the latitudinal and longitudinal distribution of the Andean Swallow considerably, and

En la provincia de Buenos Aires, el sector sur de la Bahía de Samborombón es considerado de importancia en la migración del Chorlo Rojizo, Calidris canutus. La presente nota intenta determinar la importancia de la zona de Punta Rasa en la migración de esta especie. Los resultados obtenidos, que dan cuenta de la existencia de un pico de paso migratorio en el mes de abril y de la ausencia de éste en la primavera austral (setiembre-octubre), coincide con lo observado por otros autores, insinuando que la especie utilizaría en la migración hacia el norte (otoño austral) una ruta alternativa a la utilizada en la migración hacia el sur (primavera austral).