Summer diversity of coastal birds and marine mammals in Desertores Islands, Chaitén commune (Chilean Patagonia)

Abstract

Between 24th and 27th January of 2019, was sailed the sea of Desertores Islands, commune of Chaitén, region of Los Lagos, southern Chile. This with the objective of i) estimating the richness and abundance of birds and marine mammals in the area of influence of these islands, together with ii) identifying breeding sites. So, records were made on the richness, abundance and spatial distribution of birds and marine mammals observed during navigation, and also walking on Nihuel islet (42.626° S; 72.933° W) and Barraco islet (42.737° S; 73.065° W). It was determined that the species Brown-hooded gull (Chroicocephalus maculipennis), Imperial cormorant (Leucocarbo atriceps), kelp gull (Larus dominicanus) and Silvery grebe (Podiceps occipitalis), were the most abundant coastal birds. While the South American sea lion (Otaria flavescens) and Peale’s dolphin (Lagenorhynchus australis), were the most abundant marine mammals. At the spatial level, the highest concentrations of birds and marine mammals were found in the islets Nihuel and Barraco, as well as on the coast of Talcán Island. On the islet Nihuel nest at least 2100 pairs of Imperial cormorant, which makes this place one of the most important reproductive sites for this species in Chile. Also, there is a reproductive colony of South American fur seal (Arctocephalus australis), composed of at least 890 individuals. On the other hand, the Barraco islet is used by South American tern (Sterna hirundinacea) as a nesting site, together with an interesting group of migratory shorebirds.