Diet analysis of Haematopus leucopodus in Playa Ezquerra, north of Golfo San Jorge, Chubut, Argentina.

BALA LUIS; COLAZO ANA; MUSMECI LUCIANA; CASTILLO JOANNA M

Congreso; VIII Western Hemisphere Shorebird Group Meeting; 2019

Audubon Panamá

The Austral Oystercatcher (Haematopus leucopodus) is an endemic shorebird of Patagonia Argentina. However, there is little information about their diet in north of their distribution. The diet of this species was characterized at Playa Ezquerra, north of Golfo San Jorge (Argentina), through the analysis of faeces. In March 2017, 32 faeces from a monospecific band were collected and analyzed under a magnifying glass by means of the recognition of key pieces. The frequency of occurrence of prey in the faeces was calculated. The jaws-size ratio of polychaetes ingested from the jaws found in the faeces was estimated, through a regression used polychaetes collected in the intertidal. In addition, was used the Savage selectivity index to evaluate the sizes of selected polychaetes based on the sizes available in the intertidal. The main preys consumed were polychaetes (100%) followed by crustaceans (75%) and molluscs (18.7%). Within the polychaetes the Nereididae sp. and Onuphidae sp. were the most consumed (93.7% and 40.6% respectively). It was found that the size of the Nereididae s.p consumed by the oystercatchers was 6.0 ± 1.7 cm with a range between 1.6-13.1 cm. The values of the Savage index indicated that the oystercatcher selected Nereididae sp. larger than 4.5 cm. This result show that the most important prey for the southern oystercatcher in Playa Ezquerra are the polychaetes