Carlos Aquiles Darrieu

Seeds in the Diet of the White-rumped Sandpiper in Argentina

Abstract The White-rumped Sandpiper (Calidris fuscicollis) breeds in Alaska and Canada, and during the nonbreeding season migrates to South America. The reported diet of this sandpiper is principally invertebrates; seeds are a very rare item. This species was studied at Guamini Pond, Buenos Aires Province, Argentina, in December 1997. The stomach contents of 23 adults were investigated. The analysis showed that during the sampling period the only food eaten by the White-rumped Sandpiper were seeds. Them were represented by the following families: Caryophylaceae, Chenopodiaceae, Fabaceae, Malvaceae, Polygonaceae, Ulmaceae, Cyperaceae and Poaceae. The seeds ranged between 0.83 and 2.25 mm in length. Stones and fragments of algae were found in all samples, the algae possibly ingested accidentally during feeding. Our findings indicate that the White-rumped Sandpiper forages on different items depending on the area, season and availability, and may be an opportunistic feeder.—The White-rumped Sandpiper ( Calidris fuscicollis ) breeds in Alaska and Canada, and during the nonbreeding season migrates to South America. The reported diet of this sandpiper is principally invertebrates; seeds are a very rare item. This species was studied at Guaminí Pond, Buenos Aires Province, Argentina, in December 1997. The stomach contents of 23 adults were investigated. The analysis showed that during the sampling period the only food eaten by the White-rumped Sandpiper were seeds. Them were represented by the following families: Caryophylaceae, Chenopodiaceae, Fabaceae, Malvaceae, Polygonaceae, Ulmaceae, Cyperaceae and Poaceae. The seeds ranged between 0.83 and 2.25 mm in length. Stones and fragments of algae were found in all samples, the algae possibly ingested accidentally during feeding. Our findings indicate that the White-rumped Sandpiper forages on different items depending on the area, season and availability, and may be an opportunistic feeder. Received 25 October 2002, accepted 29 December 2002.

White-faced Ibis Diet in Argentina

Abstract Seasonal composition and sexual differences in the diet of the White-faced Ibis (Plegadis chihi) were investigated in Buenos Aires Province, Argentina. A total of 88 stomach contents were analyzed, from White-faced Ibis feeding on riparian pastures and grasslands in the Magdalena district, Buenos Aires Province, Argentina. Samples were obtained between 1992 and 1996, covering each season of the year. The trophic spectrum was determined based on the identification of 59 items, mainly belonging to animal taxa. Diet was composed of Insecta (43 items), Arachnida (3 items), Crustacea (5 items), Gastropoda (3 items), Hirudinea (3 items), Amphibia (1 item) and vegetable (1 item). Dietary composition was analyzed in terms of number, frequency of occurrence and volume, for each season and between sexes. Significant differences between sexes were found in the volume of the ingestion consumed.

Avifauna (Non Passeriformes) of Santa Cruz province, Patagonia (Argentina): annotated list of species

The birds (Passeriformes) of Santa Cruz province, Argentina, are analyzed based on three main sources: specimens housed in the Museo Argentino de Ciencias Naturales of Buenos Aires (MACN), in the Felix de Azara Collection, Buenos Aires (CFA), in the Museo de La Plata, La Plata (MLP), in the Fundacion Miguel Lillo, Tucuman (FML) and in the National Museum of Natural History, Washington (USNM). The data were obtained from bibliographical citations which include precise localities and from field observations. A list of 75 species belonging to 13 families is included. First records with precise localities are provided for five species. New localities are cited for 64 species.

Aves del Alto Valle del Río Negro, Argentina

Birds from Alto Valle del Rio Negro, Argentina . A list of 49 species of 17 Non-Passeriformes and 32 Passeriformes based on a) specimens collected by W. H. Partridge (between February 1962 and June 1963) at the localities Ingeniero Julian Romero, Chichinales, Villa Regina and Chelforo (housed in Museo Ar-gentino de Ciencias Naturales), and b) literature records with precise localities. First records with precise localities are provided for 28 species. Three additional species were previously mentioned prior to the early twentieth century. New localities are cited for the rest of the species.

Winter diet of Great Pampa-finches Embernagra platensis in Guaminí Lagoon, Argentina

Abstract. The diet of the Great Pampa-finch includes seeds rather than insects. Our objective was to study its diet during the winter season and, whenever possible, to record differences between the sexes in diet patterns. This species was studied at Guamini Lagoon, Buenos Aires Province, Argentina. The stomach content of 38 adult birds was investigated. The analysis shows that the food eaten by E. platensis consisted of seeds (60%) (Chenopodiaceae, Asteraceae, Ciperaceae and Poaceae) and insects (39%) (Bellostomatidae, Dytiscidae, Curculionidae, Coccinelidae, Formicidae and Apidae). Males ate more insects and, overall, more items than females. These, in turn, consumed a greater amount of plants. Niche breadth values were 2.9 for males and 3.1 for females. The seeds encountered were those of plant species typically associated with the pampas.