One of the 4 rorquals on WAnimals

Mammals · Artiodactyla · Balaenopteridae

Sei Whale

Balaenoptera borealis

Endangered

It faces a very high risk of extinction in the wild in the near future. See full glossary

The sei whale is the third largest baleen whale, after the blue whale and the fin whale, and the fastest of all the great cetaceans. It is slender, with a tall, falcate dorsal fin. It filters copepods and krill by swimming on its side near the surface, rather than taking the great mouthfuls of the other rorquals. Twentieth-century commercial whaling removed close to 80% of the world population when the fleets, having exhausted the blue and fin whales, turned to it.

Weight

15 t – 30 t

Size

12 m – 17 m

Lifespan

65 years

Diet

Carnivore

Feeds mainly on other animals.

Sighting difficulty

Hard

Fun facts

  • locomociónIt is one of the fastest whales known and can reach remarkably high speeds over short distances, quite against the popular image of whales as slow animals.
  • It is the fastest of the great cetaceans: it can hold more than 50 kilometres an hour over a short burst, a dolphin's speed in a twenty-tonne animal.
  • Unlike its relatives, which gulp down enormous mouthfuls of water, it feeds by swimming on its side at the surface with its mouth ajar, straining plankton continuously as the right whales do.

Life cycle & biology

Skeleton type
Vertebrate - internal bony skeleton (mammal)
Habitat & environment
Temperate and subpolar oceanic waters worldwide, far from the coast
Sexual maturity
10 years
Gestation / incubation
11.3 months
Litter / clutch size
1

Sources consulted: https://es.wikipedia.org/wiki/Balaenoptera_borealis

Related species

Other species in the catalogue with the most in common with Sei Whale — same habitat, park, country, tags or family.

How to help

The sei whale is classified as endangered. Organizations such as UICN, WWF y Wildlife Conservation Society work specifically on its conservation and that of its habitat; looking into their programs is a good starting point if you want to get involved.

It's documented in 9 real protected areas — part of why protecting these places matters for its conservation.

Keep exploring

Based on what we already know about sei whale.

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