Pygmy blue whale
Balaenoptera musculus brevicauda
- Colour: Mottled grey and white which may appear silver or blue when viewed from a distance or underwater
- Appearance: They have long, slender bodies with a small dorsal fin located towards the tail and a U shaped head. Their blow is long and bushy and can reach up to 8 metres in height
- Size: reach a length of 24 metres
Pygmy Blue Whales are usually found migrating up and down the coast or in areas of high productivity along the continental shelf. They are shy, reclusive whales and rarely breach out of the water, preferring instead to concentrate on hunting for krill.
What to Observe
- How many adults and calves
- Behaviour: stationary, milling (lazing around), feeding, active (describe in the comments if the whale was jumping, rolling or waving its fins), travelling (and travel direction).
- Distance from shore (Hint: If you're unsure use a nearby buoy or other feature of know distance from shore)
- Weather and sea state (cloud cover, wind and swell)
- Photograph of dorsal fin (photo tip: Individual PBW can be identified by the unique scars and patterns on their tails. Tail photos are best taken from behind the whale after it has raised its body and tail to enter a dive. Photos should be taken of all whales sighted and having your camera set to ‘continuous shooting mode’ will ensure the best possible chance of clear identification from photos)
ClimateWatch Science Advisor
Climate change may reduce the productivity of the Southern Ocean, impacting the distribution and availability of the Pygmy Blue Whale's main food source: Krill. Changes to ocean circulation patters and temperate could affect the timing and location of PBW migration and breeding. Competition with humans and other whales for food sources and increasing interaction with tourist vessels and commercial shipping, may cause population stresses. We expect it to alter their feeding behaviour and migration in response to changes in ocean currents, temperatures and stress caused by increasing human interaction.
When To Look
- WA - February to May and November to December
- VIC - December to May
Where To Look
Found as far south as the sub-Antarctic and Southern Indian and Southern Atlantic Oceans, however they usually prefer slightly warmer waters than most Southern Hemisphere whale species. Two main populations can be found at feeding areas on the Australian coast: in southern WA near the Perth Canyon and in western Victoria near Portland. Whales from these feeding areas migrate north annually to calving grounds thought to exist near Indonesia and Papua New Guinea.
“Antarctic” blue whales (Balaenoptera musculus) are also sighted in Australian waters. Distinguishing between the two species is difficult when observing non-adults. Adult Antarctic blue whales are slightly larger (up to 30 m) and have a more pointed rostrum (snout). Most blue whales sighted in WA are likely to be Pygmy Blue Whales (Balaenoptera musculus brevicauda), which occur in greater numbers in temperate areas.
Did You Know?
Scientists know very little about where or when PBW breed and where they go when they leave the south or southwest coasts of Australia. They have recently been spotted near Exmouth in WA and new satellite tag data indicates they migrate as far north as Indonesia and possibly Papua New Guinea.