North Atlantic Right Whale – Eubalaena glacialis
Habitat: No specific habitat identified in eastern North Atlantic; historical whaling records suggest that most North Atlantic right whales taken off Great Britain and Ireland were <40 km from land, over the continental shelf.
Description: A rotund, square-chinned whale with large head (up to 25% of body length in adults), narrow rostrum and arched lower jaws. Black in colouration, occasionally with white patches on chin and belly. Callosities (dark or light thickened skin which may appear barnacle-like) present on head and around blowhole. No dorsal fin. Baleen plates partially exposed above water when skim feeding; they are black or brown, long (2 – 2.18 m in length) and narrow (up to 18 cm wide); 205 – 270 plates are present on each side. Social behaviour is poorly understood, but generally seen singly or in pairs, except for during courtship activity when up to 40 individuals may gather.
Size: 14-16m on average (max. 18 m), females larger.
Weight: 50,000 – 56,000 kg, occasionally up to 90,000 kg.
Lifespan: Unknown; one individual known to be at least 60 years old.
Distribution: Mainly between 20° – 70° N in Northern Hemisphere (mainly temperate zone) in western and eastern North Atlantic. Few recent sightings in British and Irish waters have all occured May – September. Historical range of eastern North Atlantic population included NW Africa, the Azores and Mediterranean, Bay of Biscay, western Ireland, the Hebrides, Shetland, the Faroes, Iceland, and Svalbard; sightings since 1920s have been sporadic and reduced in range.
Diet & Feeding: Skim feeds on zooplankton at surface and at depth; primarily feeds on copepods, occasionally on euphausiids (krill). No feeding documented recently in eastern North Atlantic.
Breeding: Calves are born early December – late March after gestation period of 12 – 13 months. Calves are 4 – 5 m long at birth, growing rapidly to attain 8 – 9 m by end of first year. Lactation lasts 10 – 12 months on average, occasionally up to 17 months. Cows probably reach sexual maturity at 9 or 10 years of age. Calving intervals increased from slightly over 3 years in the 1980s to >5 years in the 1990s; the interval seems to have returned to about 3 years as of 2001, and the cause of this variation is unknown.
Conservation Status & Population: Listed by IUCN as endangered. Current population is estimated at around 400 individuals. Eastern North Atlantic stock represented by a few tens of individuals at most; data suggests there may not be a separation between western and eastern North Atlantic stocks. Best hope for the return of right whales to European waters is recolonisation from western North Atlantic stocks.
Historically, whaling took a heavy toll on the population; it was considered the ‘right whale’ to hunt due to giving high yields of oil and baleen, being slow moving, and floating after death. Contemporary threats include collisions with large ships and entanglement in fishing gear; these account for over 50% of all mortality, and 75% of all right whales display scars from entanglement in fishing gear. Cumulative impacts of human activities (including whale watching) are not well understood. Impacts from climate change may be anticipated.
Dark colouration and lack of dorsal fin is unmistakeable. Blow is distinctively v-shaped, up to 7 m high. Flukes are raised above water on diving and are broad (up to 6 m tip to tip) and black. Patches of thickened skin – callosities – on head may be grey, black, cream, or light yellow, and are unique to each individual.
Vocalisations: Relatively vocal. Produces mainly moans in the 400 – 3200 Hz range, lasting 0.5 – 6.o seconds, often with pulsive and tonal components. More complex calls assocaited with sexual activity; AM moans with major energy around 0.05 – 0.2 kHz. Most common call (probably contact call) is FM upsweep with major energy at 0.05 – 0.2 kHz. High call is an FM sweep with major energy at 0.2 – 0.5 kHz and multiple frequency shifts. Other sounds made during social interactions include blows (major energy 01 – 0.4 kHz) and slaps (major energy 0.05 – 1kHz).