CESIMAR - CENPAT   25625
CENTRO PARA EL ESTUDIO DE SISTEMAS MARINOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Preliminary data of the diet of White-Rumped Sandpiper and the Two Banded Plover at Medanos beach, Gulf of San Jorge, Argentina
Autor/es:
CASTILLO,JOANNA; MUSMECI, LUCIANA R.; BALA, LUIS O.
Lugar:
Paracas
Reunión:
Congreso; VII Reunión de Aves Playeras del Hemisferio Occidental; 2017
Resumen:
The White-rumped Sandpiper (Calidris fuscicollis) and the Two-banded Plover (Charadrius falklandicus) use the intertidal zones of the San Jorge gulf as a feeding and resting place during their migrations. The diet of these species was studied in Medanos beach, during March 2017, by analysis of fecal samples collected after observing monospecific flocks feeding in different sites of the same beach. The community of benthic invertebrates was sampled in order to study the food supply in each site (A and B, where the sandpipers and plovers were feeding, respectively). It was determined that both species consumed mainly polychaete Laeonereis acuta, although the sizes ingested differed significantly (p=0.00046). The L. acuta ingested by plovers were larger (82.8±25.8 mm) than those ingested by sandpipers (34.5±16.1 mm). On average, each feces of plover had 3.03±1.9 L. acuta, and each feces of sandpiper had 4.2±1.7 L. acuta, representing a total biomass of 0.30±0.08 mg and 0.65±0.03 mg respectively. Differences in the diversity of prey between sites were not found, and the key prey were L. acuta, followed by Capitella sp. and amphipods in site A, and polychaetes such Capitella sp. and Arenicolidae in B. The density of L. acuta in site A was highest (2664.5±1008.9 ind/m2) and with smaller sizes (42.6±8.1 mm), and lower in B (808.8±494.4 ind/m2) with larger sizes (82.8±25.8mm). We discuss dietary differences among species, associated with the different strategy of prey capture, and the different food supply at each site.