Cetaceans are a group of closely related mammalian species that consists of whales, dolphins and porpoises. Two cetacean species can regularly be found in the waters surrounding Ascension. The bottlenose dolphin is resident year-round and can be observed close to shore at sites such as Porpoise Point and Boatswain Bird Island. Humpback whales also pass through each year to calf. A number of other species have been recorded in Ascension's waters including Gervais' beaked whales and pan-tropical spotted dolphins, but these are observed less regularly and normally further offshore.