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Sei Whale

Background - 8 January, 2009

Sei whale and calf

Estimated Population: N/A endangered

Ways to identify this species:
slim and streamlined, bluish grey body with a white underside


Migratory, Sei whales feeds in arctic waters in the summer and subtropical waters during the winter where it remains mainly offshore

Sei whales are the third largest baleen whales. The largest known speciment measured 20m in length, although most are between 12-15m long. Females are usually larger than males.

They are one of the fastest swimming cetaceans and can reach speeds of 50 kph.

Sei whales tend to swim in pods of 3-5 animals, and rarely dive deeper than 300 m. Although little is known about how this species communicates, it has been found that low-frequency pulses are common.

They eat mostly small schooling fish and other organisms like squid and plankton.


After fin and blue whale populations were exhausted, Sei whales became the target of whalers in the 1950's and 60's and the population was severely depleted.

Today it still faces threats from hunting and entanglement in nets.