Northern Bottlenose WhaleFact sheet |
Northern bottlenose whale
|
|
 |
|
| Length | 6 to 10 m |
| Weight | 3 to 7 t |
| Sociability | Sometimes solitary, often in groups of 5 to 15 individuals; during migration these groups can number several hundred individuals |
| Longevity | approximately 40 years |
| Dive time | 3 to 70 min, up to 2 hours |
| Observations | The only individuals sighted in the St. Lawrence had stranded themselves |
| Worldwide distribution | Cold and temperate waters of the North Atlantic |
| Worldwide population | Unknown, numbers greatly reduced |
| Status in Canada | Endangered |
Description
-
Prominent melon and beak
-
Adult males have white melon
-
Females have whitish neck collar
-
One pair of teeth at tip of lower jaw, only in adult males
-
Small, pointy pectoral fins
When it surfaces: Its blow is balloon-shaped, rarely visible and can attain a height of two metres. Its long beak and melon sometimes emerge. Its falcate dorsal fin is situated two thirds of the way along its back and becomes apparent near the end of its surface cycle.
A deep diver
The northern bottlenose whale is an infrequent visitor to the St. Lawrence. It is capable of diving to great depths for extended periods of time. These abilities enable it to feed at depths in excess of 1000 metres. Such is the case in the Sable Island Gully, off Nova Scotia, where, a small, distinct population of northern bottlenose whales, known as the Scotian Shelf population, lives year round.
Population, range and habitat
In the St. Lawrence: Bottlenose whale sightings are extremely rare in the Gulf and Estuary. Fewer than 10 of these animals have been found stranded along the St. Lawrence since 1994.
Migration: The northern bottlenose whale does not appear to follow a seasonal north-south migration, although complex movement patterns have been observed for this species that lives near the pack ice boundary. The Scotian Shelf population resides year round near the Gully in a tight-knit group.
Worldwide: The northern bottlenose whale can be found in the deep, cold waters of the North Atlantic from 40°N to 80°N. Western North Atlantic populations live off Cape Cod, Nova Scotia, Newfoundland and in the Arctic. A small, genetically distinct population of approximately 160 bottlenose whales frequents an area situated some 200 km off the coast of Nova Scotia in a sector known as the Sable Island Gully, which is an underwater canyon rich in marine species diversity. One third of this population lives here year round.
Behaviour
Feeding: While its preferred prey is squid, the northern bottlenose whale indulges in a varied diet of prey species that live at great depths or on the sea floor. These include herring, ground fish, shrimp, sea cucumbers and starfish.
At the surface: Northern bottlenose whales often surface for 10-minute intervals, interspersed with 30 to 40 second breathing cycles. They alternate resting periods with rapid swimming sequences, changing direction frequently. Occasionally curious about boats, they may approach and even swim around stationary vessels. They rarely fluke up when they dive deep.
While diving: The northern bottlenose whale dives to great depths. Data from the Gully has revealed that it regularly dives to the bottom of the ravine, 1400 to 1500 m below. Dive durations generally vary between three to 70 minutes, the record being two hours.
Social behaviour: This is a gregarious species, forming pairs and groups of three to a dozen at a time. Individuals appear to establish long-term, same-sex relationships. Members of a group will not abandon an injured animal.
Vocal behaviour: The northern bottlenose whale emits whistles, gargles, modulated sounds and clicks. Ultra-high-frequency echolocation sounds are used for navigation and to find food. Other vocalizations are used for communication purposes.
Reproduction
The northern bottlenose whale attains sexual maturity between seven and 10 years of age. Calving takes place in April and June, as late as August for the Gully population. Gestation and nursing last 12 months, each.
About scientific research
Dr. Hal Whitehead of Dalhousie University has been carrying out a long-term study of the small, fragile Gully population since 1988. Dr. Whitehead's studies include acoustic surveillance, radio tracking. Dr. Whitehead and his team have put together a catalogue of 160 individual whales based on dorsal fin marks. Primary threats to the survival of these whales include chemical pollution, accidental entanglement in fishing gear and noise pollution generated by local oil and gas exploration.
|
|
|
|
Consult past weekly updates.
Receive our weekly update by email.
Send us your comments.
