Review of the distribution ofMesoplodonspecies (order Cetacea, family Ziphiidae) in the North Atlantic

Four species of beaked whales of the genus Mesoplodon regularly occur in the North Atlantic. These are Sowerby's Beaked Whale Mesoplodon bidens , Blainville's Beaked Whale Mesoplodon densirostris , Gervais Beaked Whale Mesoplodon europaeus and True's Beaked Whale Mesoplodon mirus . These four species differ in their distribution within this area. M. bidens is the most northerly recorded species followed by M. mirus . M. densirostris and M. europaeus both generally occur further south and their distributions cross the equator. The distribution of Mesoplodon species may relate to variations in water temperature.