Taxonomy & Nomenclature
Physical Description / Field Identification
Northern bottlenose whales are appropriately named; they have a tube-like snout that is distinct from the melon. In young animals and females, the rounded forehead slopes upward from the beak, but in adult males the forehead becomes very steep, with a nearly-squarish profile. A pair of forward-pointing grooves is found on the throat. The small dorsal fin is falcate and is located far back on the body. The flippers are small and blunt at the tips, and the flukes generally lack a median notch.
Calves are generally gray on the body, with complex light coloration on the head. There is some disagreement as to whether young animals are countershaded. Adults are dark grayish to chocolate brown above and somewhat lighter below. The brownish tinge is often enhanced by a covering of diatoms. Some individuals are mottled with white to yellowish splotches and scars, which increase in number with age. Much of the melon and face may be light gray, or in adult males nearly white.
At the tip of the lower jaw are two conical teeth that erupt only in bulls, and are not visible outside the closed mouth. A second pair of teeth is sometimes buried in the gums behind the first, and 10-20 additional vestigial teeth may be found in the gums of both upper and lower jaws.
Adult females are up to 8.7 m and adult males up to 9.8 m in length. At birth calves are about 3.5 m.
Can be Confused With
Cuvier's beaked whales can be distinguished from bottlenose whales by differences in head shape and body color. Mesoplodonts, especially Sowerby's beaked whale are distinguishable by their smaller size and more cone-shaped head.
Northern bottlenose whales are found only in the North Atlantic, from New England to Baffin Island and southern Greenland in the west and from the Strait of Gibraltar to Svalbard in the east. However, there have been strandings at least as far south as North Carolina in the western Atlantic. These cold temperate to subarctic whales are found in deep waters, mostly seaward of the continental slope. It forms an antitropical species pair with the southern bottlenose whale.
Ecology and Behavior
Most groups contain at least four whales, sometimes with as many as 20, and there is some segregation by age and sex. These deep-divers can remain submerged an hour, possibly as long as two, and can reach depths of over 1,400 m. They are known for their habit of "standing by" injured companions, which permitted whalers to kill large numbers of whales at the same site. Bottlenose whales are also often curious and attracted to stationary vessels.
Northern bottlenose whales have a peak in calving in April. There is a well-studied population in the “Gully” (a large submarine canyon off the coast of Nova Scotia, Canada). Individuals in this population can be identified by natural markings, and several long-term studies have been conducted on them.
Feeding and Prey
Although primarily adapted to feeding on squid (especially Gonatus sp.), these whales also eat fish, sea cucumbers, starfish, and prawns. They apparently do much of their feeding on or near the bottom.
Threats and Status
This is one of only a few species of beaked whales to be hunted commercially on a large scale, largely by Canada and Norway. Hunts occurred from the 1850s to the 1970s, and over 80,000 whales were killed. Current numbers are thought to be still depleted, due to these large kills.
Northern bottlenose whales are currently “Lower Risk/Conservation Dependent” (IUCN) and “Not Listed” (ESA).
Gowans, S. 2002. Bottlenose whales Hyperoodon ampullatus and H. planifrons. pp. 128-129 in W.F. Perrin, B. Würsig and J.G.M. Thewissen (eds.), Encyclopedia of Marine Mammals. Academic Press.
Hooker, S.K. and R.W. Baird. 1999. Deep-diving behaviour of the northern bottlenose whale, Hyperoodon ampullatus (Cetacea Ziphiidae). Proceedings of the Royal Society, London 266B:671-676.
Mead, J.G. 1989. Bottlenose whales Hyperoodon ampullatus (Forster, 1770) and Hyperoodon planifrons Flower, 1882. pp. 321-348 in S.H. Ridgway and R. Harrison (eds.), Handbook of Marine Mammals, Vol. 4: River dolphins and the larger toothed whales. Academic Press.
Reeves, R.R., E. Mitchell and H. Whitehead. 1993. Status of the northern bottlenose whale, Hyperoodon ampullatus. Canadian Field-Naturalist 107:490-508.
Whitehead, H., A. Faucher, S. Gowans and S. McCarrey. 1997. Status of the northern bottlenose whale, Hyperoodon ampullatus, in the Gully, Nova Scotia. Canadian Field-Naturalist 111:287-292.