Further names: Portuguese: Baleia-sardinheira
Size of adults: Females 16-19 metres (larger than males)
Prey: Primarily zooplankton (planktonic crustaceans) but also schooling fish. Like most other rorquals, Sei whales are lunge feeders accelerating to gulp large amounts of water before forcing it out through the sides of their mouths filtering out their prey in the process.
Behaviour: Very little is known about their social behaviour. Usually react evasively towards boats but occasionally allow an approach. May be encountered in small groups of two to six individuals.
Range: Occurs worldwide from subtropical and tropical waters to colder regions. Inhabits shelf and oceanic waters. Sei Whales undertake seasonal migrations, moving to higher latitudes in summer and tropical waters in winter.
Madeira: Mainly encountered in the spring and summer months
Distinctive features: Tall, heart-shaped spout and prominent, falcate dorsal fin. Their build is similar to that of the Bryde’s whale except slightly more robust. One central rostral ridge extending from the blowhole to the snout.
Taxonomy: Suborder: Mysticeti (Baleen whales); Family: Balaenopteridae (Rorquals)
Threats: Insufficient data on population size. Sei whales are still victims of whaling in the western Pacific and are additionally threatened by vessel collisions, fishing nets and noise pollution.