Bryde's Whale

Bryde's Whale: Balaenoptera brydei

IUCN status: Data deficient

Status and distribution summary:

Bryde's Whales is a warm water species that is rarely found at higher latitudes than 400, eg mid Portugal or New York. Although there have been a number of records from further north in recent years. They are probably most abundant in the northern Pacific, but are regularly seen around the Macaronesian archepelago in the Atlantic.

However, it is unlkely that this is a single species, and DNA analysis points to at least three species, of which Bryde's Whale has the widespread oceanic distribution and the other two are found around the tropical seas of the western Pacific and Indian oceans.

No accurate population estimates exist for Bryde's Whale.

Exploitation:

Prior to the 1970s was not differentiated from Sei Whales by whalers. Since then has largely escaped the intensive whaling in higher latitudes that had a marked impact on other species of baleen whale, but was taken by Russian and privateer whaling operations in the western Pacific and off South Africa. Today Japan kills c50 Bryde's Whales a year in the western North Pacific, and small numbers are taken in some aboriginal hunts.

Other threats:

Not known to suffer significant mortality from by-catch or ship strikes. Well documented incidence of a young Bryde's whale dying from plastic bag ingestion (film on YouTube).

Where it is seen:

Vagrant to Biscay and north west European waters.

Frequency of sightings:

One photographed in 2010 over deep water in southern Biscay.

Recognition:

A moderately large whale (up to 15 metres in length). Streamlined.

In regular surfacing they usually show the following features:

  • Dark grey, sometimes blueish; black in poor light. Often appears mottled, this is caused by bites from Cookie-cutter Sharks
  • Dorsal fin is set 2/3 to 3/4 back to the flukes. Variable but usually relatively tall, swept back and falcate with a fine tip
  • Blow is tall and columnar; not a good identification feature
  • Has an extra ridge on the rostrum, either side of the main rostral ridge. This is unique to Bryde's Whales and diagnostic if photographed

Behaviour:

Usually seen alone or in pairs.

Blows every 20 - 40 seconds for up to 5 minutes. The last dive in the sequence usually with a steeply arched tailstock.

Breaches only rarely, normally only once at a shallow angle.

Confusion species:

  • Sei Whale: similar size, would usually appear darker and with a taller more erect dorsal fin located further forward
  • Fin whale: larger with usually stronger blow. Proportionately smaller and blunter tipped dorsal fin