Marine mammals of Easter Island (Rapa Nui) and Salas y Gomez Island (Motu Motiro Hiva), Chile: a review and new records

Abstract

The Chilean oceanic islands Easter Island (Rapa Nui) and Salas y Gomez Island (Motu Motiro Hiva) have received little attention with regards to basic marine mammal investigations. Here we review and update available information on the status of marine mammals in this area from different sources, including published accounts, local interviews and two recent expeditions. We also provide detailed accounts for each confirmed family or species, including historical data from published archaeological studies and whalers' logbooks from the 18 th to the 20 th centuries. Results indicate that a total of five marine mammal families (Balaenopteridae, Physeteridae, Ziphiidae, Delphinidae and Phocidae) have been confirmed within the study area, representing two mammalian orders (Cetartiodactyla and Carnivora). Within these, twelve species are known to occur: blue whale (Balaenoptera musculus), unidentified minke whale (Balaenoptera bonaerensis or B. acutorostrata), humpback whale (Megaptera novaeangliae), sperm whale (Physeter macrocephalus), Cuvier's beaked whale (Ziphius cavirostris), Blainville's beaked whale (Mesoplodon densirostris), false killer whale (Pseudorca crassidens), unidentified pilot whale (Globicephala sp.), bottlenose dolphin (Tursiops truncatus), common dolphin (Delphinus sp.), southern elephant seal (Mirounga leonina) and leopard seal (Hydrurga leptonyx). We discuss the implications of some of most noteworthy records and make a plea for further studies to improve our knowledge of these top predators in one of the most isolated places in the world.