Whales

Bryde’s Whale - Balaenoptera brydei

It seems from genetic research conducted on this species, that the Bryde’s Whale is not a single species, but in fact, is two – the regular and pygmy form. The pygmy averages just one or two meters shorter in length than the regular species. It also seems the regular Bryde’s whale consists of an ‘inshore’ and ‘offshore’ type, both differing in movement, distribution and ecology.

The Bryde’s Whale has a very broad and short head, with relatively large eyes. It has three longitudinal ridges on its head, from the tip of the snout to the blowhole, whereas other rorquals have just one ridge. Its colour is generally dark grey, with the ventral side being a lighter cream, shading to greyish purple on the stomach. Most have a number of white spots which may be scars from parasites or from attacks from sharks, giving it a blotched appearance. The dorsal fin is large and upright and can easily be seen when the whale surfaces and its flippers are small and slender. The whale has two blowholes with a low splashguard to the front, no teeth but has two rows of baleen plates. They feed on schooling fish, such as anchovy and herring. It has been seen to lunge up through shoals of fish, sometimes exposing the whole head with the mouth wide open, and scattering any animals that get in the way.

The Bryde’s Whales seem to prefer tropical and temperate waters to the polar seas that other whales in their family frequent and are largely coastal. They are distributed widely throughout tropical and subtropical waters, with a separate but smaller, pygmy species found in tropical Western Pacific and South-East Asia.

They are usually found alone, however, they are also known to gather into small groups when feeding. They are not particularly fast swimmers, but they can move rapidly when disturbed. Equally, they are not deep divers, usually spending no more than about two minutes underwater, although dives as long as four minutes have been recorded.

In the North Pacific, Bryde’s whales have a definite breeding season and though very little is known of their reproductive cycle in this area, the resident whales presumably mate and gives birth there. After a one year gestation period, females give birth to a single calf measuring about 4 meters in length and weighing one tonne. The newborn is nursed during the following year, before the female once again falls pregnant.

As a result of several decades of misidentification, statistics for this species are greatly confused and therefore it is impossible to know how many of each form of these whales were actually killed and indeed how many are left today.