Northern bottlenose whale
The northern bottlenose whale is a large member of the beaked whale family. Their most distinguishing feature is their short dolphin-like beak that occurs just in front of their bulbous-shaped forehead. Northern bottlenose whales have a North Atlantic distribution. They occur from the coast of Maine northward in the West Atlantic and from the United Kingdom northward in the East Atlantic. They occur northward to the summer ice edges on both sides of the Atlantic.
The northern bottlenose whale is a large member of the beaked whale family. They are dark grey-brown in colour with lighter flanks and belly. They have some irregular, lighter spotting on the back.
The dorsal fin is small, backward pointing and occurs quite far back on the body towards the fluke. Their most distinguishing feature is their short dolphin-like beak that occurs just in front of their bulbous-shaped forehead. Males are 8.5–9 metres long and weigh 7,000–8,000 kg, whereas females are smaller, being approximately 7.5 m long and 5,000–6,000 kg.
The northern bottlenose whale exhibits pronounced sexual dimorphism in the shape of the head. The forehead of males becomes very bulbous as they become sexually mature eventually becoming almost square whereas the forehead of females is more smoothly rounded and smaller.
Calves are grey with dark eye patches and a light-coloured forehead when they are born.
Northern bottlenose whales have a North Atlantic distribution. They occur from the coast of Maine northward in the West Atlantic and from the United Kingdom northward in the East Atlantic. Stranded animals have been reported from as far south as France and Rhode Island, USA, in the east and west respectively. They occur northward to the summer ice edges on both sides of the Atlantic.
In the East Atlantic there appears to be a set migratory pattern, with animals moving northward in the spring and southward again in the late summer. Migratory patterns, if they occur, are not as well defined in the West Atlantic. There appears to be onshore and offshore migrations, but some animals appear to be resident in a few hotspots, such as the Gully Region off the coast of Nova Scotia.
This species is a deep-water animal that usually remains beyond the continental shelf, so is not commonly sighted in coastal waters. In the Svalbard region they are sighted offshore on the western side of the Archipelago during the summer months; occasionally stranded animals wash up on islands or in fjords along the west coast. Only mature males travel into the High Arctic, females and younger animals are found much further to the south. So all northern bottlenose whales in Svalbard waters are male.
There is no population estimate available for northern bottlenose whales in the North Atlantic. The northern bottlenose whale is a social species that occurs in small groups that number from a few individuals up to 20. Groups are segregated by age and sex.
Females appear to have a loose network of associations with other individuals, but group membership shifts a lot and most associations are brief. Mature males are found in quite stable groups and individuals often remain together over a period of years.
Like other beaked whales, the bottlenose whale has very few teeth. Males of this species possess only two conical shaped teeth located at the tip of the snout; females have no teeth.
They are exceptionally deep divers that can remain submerged for over an hour during a dive. They have been recorded to dive to depths of nearly 1,500 m. Northern bottlenose whales are predominantly squid eaters, although they do take other prey such as sea cucumbers, fish and shrimps that occur near the bottom. Killer whales probably take calves occasionally.
Life history and reproduction
This species calves in April in the Gully off the coast of Nova Scotia in Canada. Very little is known about the life history of this species.
Management status and monitoring
The northern bottlenose whale has been hunted on both sides of the Atlantic. Despite their relatively dispersed distribution and small group size, harvests were large because groups remained with injured animals, so typically a whole group was harvested if a single animal could be injured. This species was severely depleted before it was protected in 1977. Some northern bottlenose whales are still taken in traditional harvests in the Faeroe Islands.
Northern bottlenose whales are protected in Svalbard.