Bryde's Whale

## Description

Bryde's whale ( BRUU-dəz Brooder's), or the Bryde's whale complex, putatively comprises three species of rorqual and maybe four. The "complex" means the number and classification remains unclear because of a lack of definitive information and research. The common Bryde's whale (Balaenoptera brydei, Olsen, 1913) is a larger form that occurs worldwide in warm temperate and tropical waters, and the Sittang or Eden's whale (B. edeni, Anderson, 1879) is a smaller form that may be restricted to the Indo-Pacific. Also, a smaller, coastal form of B. brydei is found off southern Africa, and perhaps another form in the Indo-Pacific differs in skull morphology, tentatively referred to as the Indo-Pacific Bryde's whale. The recently described Omura's whale (B. omurai, Wada et al. 2003), was formerly thought to be a pygmy form of Bryde's, but is now recognized as a distinct species. Rice's whale (B. ricei ), which makes its home solely in the Gulf of Mexico, was once considered a distinct population of Bryde's whale, but in 2021 it was described as a separate species.

*B. brydei* gets its specific and common name from Johan Bryde, Norwegian consul to South Africa, who helped establish the first modern whaling station in the country, while *B. edeni* gets its specific and common names from Sir Ashley Eden, former High Commissioner of Burma (Myanmar). Sittang whale refers to the type locality of the species.

## Appearance

Bryde's (pronounced "broodus") whales belong to the family of baleen whales and are regarded as one of the rorquals or "great whales". They are dark gray in color with a cream belly. The bodies are very sleek and they have a close resemblance to the sei whale. Bryde’s whales have one more ridge in front of their blowholes than the sei whale's two. They have a double row of baleen plates. The head and the eyes are very large. The dorsal fin is positioned far down the back. Their flippers are small and thin.

## Distribution

Bryde’s whales inhabit sub-tropical and tropical waters throughout the Pacific, Atlantic and Indian Oceans, preferring warm oceanic waters, in temperatures between 15 and 20 degrees C. They are pelagic and coastal creatures that generally follow their food sources.

## Behavior

The Bryde's whale usually chooses to feed alone, except for mothers and calves, who often feed together. Individuals living close to the shore may feed in groups of 15 or fewer, while those off-shore may be in groups that number up to 30. Bryde’s whales are one of the livelier species of rorqual, frequently breaching right out of the water and often making dives of one to two minutes to depths of 300 meters. Patterns of migration vary, with populations in coastal tropical waters appearing to stay in the same location for the year, while populations in subtropical waters will make limited migrations, depending on movements of prey. These whales can be very vocal while communicating with each other. They often make moaning sounds.

## Diet

Inshore groups prefer fish: anchovies, sardines, herring and mackerel, while offshore groups eat the krill of genus Euphausia and copepods, as well as cuttlefish, squid, and octopi.

## Reproduction

There is not much information about the mating habits of Bryde's whales, though they probably are similar to other related cetaceans. Bryde’s whales in tropical waters may breed throughout the whole year, while in sub-tropical seas breeding mainly takes place in autumn. Gestation lasts 11 to 12 months. Mothers produce one calf per mating season, and they nurse their calf for 6 months. After weaning, the mother leaves her calf to look after itself. Bryde's whales are sexually mature at the age of 10 to 13 years.

## Population

### Population threats

Bryde's whales face human threats in the form of colliding with large ships that are travelling in the same area. Chemical pollution is also a threat, as well as underwater sounds and noise caused by humans, as these whales, like all baleens, communicate with each other by means of low-frequency sounds.

### Population number

According to Wikipedia, the population of Bryde’s whales may include up to 90,000–100,000 animals worldwide, with two-thirds inhabiting the Northern Hemisphere. The Bryde’s whale is currently classified as Data Deficient (DD) on the IUCN Red List of threatened species.

## Fun Facts for Kids

Bryde's whales are named after Johan Bryde, a Norwegian who built the first of the South Africa's whaling stations.

Bryde's is said "Broodah's".

Bryde's whales can easily be confused with sei whales, though they are smaller and inhabit warmer waters.

A Bryde's whale is believed to consume food of about 1,320-1,450 lbs (600-660 kg) per day, about 4% of its body weight.

When diving for food, Bryde's whales can stay underwater for as long as 20 minutes before coming up for air.

Being a member of the baleen suborder, the Bryde’s whale does not have teeth, but instead it has baleen plates with bristles on them, which enable the filtering of prey from the water.

The Bryde's whale swims unpredictably and often changes route and direction for no apparent reason. Scientists have been unable to find an explanation for such behavior.