Minke whale
Balaenoptera acutorostrata

The minke whale is the smallest and most common of the baleen whales. Its shy behaviour makes it a challenge for even the most experienced whalewatcher to spot.

Description

The minke whale (pronounced ‘MINK-ee’) is the blue whale’s smallest relative. Fully grown, the minke whale can be 10 metres long and weigh 8 tonnes. The minke’s smooth body is shaped like a torpedo, and tapers at both ends. Its head is very pointed, which is why it used to be called ‘the little piked whale.’ Like all rorqual whales, its throat is lined with pleats which expand when feeding. Minkes are dark gray on top and white on their bellies. Sometimes they have faint, gray swirls on their flanks, just behind the flippers. Their blow, or spout, is low and very hard to see.

There are two special features to look for when trying to identify a minke whale. One is the dorsal fin, which is small and sharply curved. It is about two-thirds of the way along the back, and is usually seen very briefly just as the whale blows. But the surest way to identify a minke is by catching a glimpse of its pectoral flippers. There is a distinct white band on each one. No other whale this size has such markings.

Range

The minke whale is found in all the world’s oceans, from the tropics to the polar seas, in coastal and offshore areas. Very little is known about the seasonal movements of minkes, but it is believed that in the North Pacific, they generally shift northwards in the summer and southwards in the winter. They are found as far north as the Bering and Chukchi Seas.

Minkes are seen off B.C. throughout the year, but most often in the summer months. They sometimes feed or travel quite close to shore. Long-term studies in the waters off southern Vancouver Island have shown that some minkes return to the same feeding spots year after year. Finding this out was not easy. Researchers had to take thousands of photographs of these elusive whales before they could tell individuals apart by slight differences in dorsal fin shape, body colour and scars.

Behaviour

Very little is known about the social life of minke whales. No-one has found a special breeding ground, if one exists. It is thought that births take place in winter, and that calves stay with their mothers for only four to six months. That may be one reason why minkes seen off B.C. in the summer are usually alone, although it seems that minkes are very solitary whales. Like all rorqual whales, minkes are fast swimmers. They are difficult to follow, because they do not breathe regularly and often change direction. It is not unusual for one to vanish as if by magic!

Minke whales eat by either gulping or skimming. They seek out swarms of krill and small schooling fish near the surface, such as herring. They fill their expandable mouths with water and filter the food through the baleen. Sometimes, a minke whale will lunge feed by shooting straight out of the water, its mouth wide open. Minke whales are often seen feeding with noisy flocks of seabirds.

Status

Because of their small size, minke whales did not interest whalers until blue, fin, sei and sperm whales became more difficult to find. Once these larger whales were protected, the minke became a main target. Only two minkes were reported in catches from B.C.’s shore-based whaling operations.

Today, the world population of minkes is estimated to be in the hundreds of thousands, although in some regions their numbers are low. In B.C. they have always been considered fairly common, but not abundant.