Sei whales are among the most solitary of all the whales, often preferring to travel alone. They do sometimes form pods of up to six individuals, but rarely gather in larger groups. Their solitary nature, combined with their preference for warmer waters, makes them quite rare in the frigid waters of Antarctica. However, if you do come across a sei whale during an Antarctic cruise, it makes for quite a sight as they tend to stay close to the surface, skim feeding on krill and small fish.
While sei whales aren’t the most impressive divers, they are remarkably fast swimmers over short distances. They rank among the fastest of all the cetaceans and are capable of reaching speeds of around 35 mph—no mean feat for a creature weighing as much as 28 tons. Their swimming ability allows them to glide through clouds of prey on or near the surface, straining the food from the water through their baleen plates and taking in as much as 900 kg of food per day. Their speed may also help them avoid attacks from their only presumed natural predator: packs of killer whales.
The speed and elusiveness of sei whales initially helped them to avoid the worst of the whaling industry, but they were heavily targeted once stocks of more profitable whale species became depleted. Today, the global sei whale population is estimated to be around 80,000, less than a third of its pre-whaling population. The species is currently listed as endangered.
As for the name, sei whales (pronounced “say”) were named after the Norwegian word for pollock. Sei whales typically appeared off the coast of Norway at the same time as the pollock, when both species came to feed on the plentiful plankton.
Other Antarctica Wildlife
Adélie Penguin / Chinstrap Penguin / Emperor Penguin / Gentoo Penguin / Macaroni Penguin / Crabeater Seal / Elephant Seal / Fur Seal / Leopard Seal / Ross Seal / Weddell Seal / Blue Whale / Fin Whale / Humpback Whale / Killer Whale / Minke Whale / Right Whale / Sperm Whale