Sei whale

How it lives

Sei whales feed mainly by skimming near the surface, and also by gulping. They eat copepods, krill, small fish and squid, and NOAA estimates an average of about 900 kg a day. They are usually seen alone or in small groups, and more can gather where food is rich. They are among the fastest great whales and can reach more than 55 km/h (34 mph).

Where it goes

Their migrations are poorly known: sei whales may appear in an area and then stay away for years. Many move between lower-latitude winter waters and higher-latitude feeding grounds, but routes and timing are hard to predict. Stocks in different ocean basins follow different migration calendars.

We only draw a journey on the map when scientists have tracked it or clearly documented it. For this animal we have not found one yet.

Populations

Two subspecies are commonly recognised: the northern sei whale (B. b. borealis) and the southern sei whale (B. b. schlegelii). Populations in different ocean basins differ in numbers and migration. They prefer offshore waters, and where Bryde's whales also live, the two can be hard to tell apart.