Characterization of coastal waterbird assemblages of northern Golfo San Jorge, Patagonia, Argentina

The northern sector of the Golfo San Jorge has an important diversity of waterbirds and is included within the Parque Interjurisdiccional Marino Costero Patagonia Austral (PIMCPA). Waterbird assemblages that utilized the intertidal areas at PIMCPA were characterized by means of direct counts during fall and spring seasons in three wetlands representing the environmental heterogeneity of the area: Bahía Melo (45°01’S, 65°53’O), Punta Tafor (45º03’S, 66º 17’O) and Caleta Malaspina (45º10’S, 66º30’O). 253 counts were achieved during three consecutive years (2013-2015). A total of 42508 individuals corresponding to 36 species were registered. The species with higher frequency of occurrence and abundance were White-rumped Sandpiper (Calidris fuscicollis), Kelp Gull (Larus dominicanus), Crested Duck (Lophonetta specularioides), Magellanic Oystercatcher (Haematopus leucopodus), Two-banded Plover (Charadrius falklandicus) and Chubut Steamer Duck (Tachyeres leucocephalus). The assemblages composition varied between the studied seasons. During fall there was a higher abundance (29686 vs. 12822) and specific richness (33 vs. 29) than in spring. However, a higher specific diversity was registered during spring (1/D; 6.2 vs. 5.4). Waterbird specific richness at PIMCPA incremented southwards independently of the studied season. This study contributed with novel information about the spatial and temporal characterization of the waterbird assemblages that utilized these marine wetlands providing useful tools for the knowledge and conservation of the natural resources of this protected area.