scription: With the occurrence of many strandings, quite a lot more is known about Scamperdown than any other species. Medium (on the small side); length averages 3.6 m (12 ft), with a maximum of 4.2 m (14 ft). Weight averages about 1,000 kg (about 1 ton). It is the smallest of the group of mesoplodons with the usual body shape but a tendency to be both slender and laterally compressed. The head is distinctive with small melon bulge in front of the blowhole. The forehead recedes almost to the point of being entirely flattened and running directly into a long slender beak. The throat grooves are well marked; the flippers are short but nevertheless the widest in the genus; and the dorsal fin is relatively large and sharply pointed.

The teeth are not as large as several other species, but can protrude far enough to be visible in some animals. Males and females have one pair of large serrated teeth with one or more sharp points about 20 cm (8 inches) from the tip of the jaw and lean slightly forwards. The height of the teeth is about 10 cm (4 inches) and the width is normally 80 per cent of the height. In addition to this pair of prominent teeth, both males and females have a number of smaller teeth in both jaws. Scamperdown Beaked Whales commonly have up to 26 extra teeth, usually on the upper jaw behind the point of origin of the large teeth, breaking through the gum far enough to be functional.

The colour is an overall deep grey, almost black, shading to dark grey on the undersides. The throat has a varying amount of white as well as the lower jaw, while the whole body may be scattered in pale spots and scars with the majority of them on and around the slender head.

It should be relatively easy to identify this species which is believed to be highly social, to occur commonly in groups of 6 or more, and that may be more active and more conspicuous at the surface than other beaked whales. Scamperdown Beaked Whales have been described shooting up out of the water at an angle of 30° until all but the tail is exposed and then falling back with a splash. They may do this in reaction to the approach of a ship. Their appearance may be confused with that of Southern Rightwhale Dolphins (Lissodelphis peronii 63), which characteristically behave in this way, until one is able to see their larger size and that they have typical Mesoplodon dorsal fins.

They leap serially, each one rising at least once every 10 seconds, probably faster than their normal breathing rhythm. No blows are visible although they are thought to breathe approximately once every 30 seconds. Calving normally occurs in the spring.

The frequency with which Scamperdown Beaked Whales strand may be an accurate reflection of their greater abundance or may simply be the result of their more coastal way of life.