Whales (Humpback)
Knowing the basic statistics about a humpback whale does little to prepare you for the surprise and awe of seeing a 16 metre, 40 tonne mammal all but completely lift itself out of the water then crash back into the sea sending spray 10 metres into the air.
When a whale surfaces, the simple act of exhaling results in a ‘blow’ of spray and air that shoots up to 4 metres in the air as it empties 90% of the contents of its lungs in less than a second. The whale’s lung capacity is about the same volume as a small car.
Then, when it breathes in and dives, it can stay submerged for up to 30 minutes.
| Size | Usually up to 16m (females are slightly bigger) |
|---|---|
| Weight | 40–45t |
| Fluke width | Up to 4m |
| Pectoral fin length | Up to 5m (about a third of the total body length) |
| Brain size | 5kg (60cm circumference by 22cm long) |
| Heart | 1.2–1.5m long |
| Aorta | 60cm diameter |
| Blood volume | 10–15% of body weight (up to 6.5t of blood) |
| Intestines | 60m long |
| Skull | 2–5m long by up to 2m wide |
| Food consumption | Up to 2,000kg/day when feeding |
| Life expectancy | Up to 50 years |
| Gestation period | 11–12 months (whales can breed every year but usually give birth every 2–3 years) |
| Size of calf (at birth) | 4–6m |
| Breeding age | 5–7 years |
| Migration | 9,000km (round trip) |
| Speed | Generally 3.5–5.0 knots or 6.5–9.2km/h (fastest speed 9–10 knots or 18.5km/h) |
| Population size | Approximately 12,000 in 2008 (increasing by around 10% each year). Current estimate 40,000. |
White whales
At least 3 white whales are migrating along the east coast of Australia. Migaloo and Bahloo have been seen in Queensland waters. The third (a calf) was briefly seen off Sydney in 2008.
In Queensland, whales that are totally white or predominantly white can be declared ‘whales of special interest’. This gives these whales extra protection from being disturbed, by increasing the distance that boats and other watercraft must keep from them.
Migaloo
Migaloo is a white humpback whale that was first seen in 1991 off Byron Bay. At the time it was believed to be 3–5 years old. It has been seen migrating along the east coast in most years since then in Tasmania, Victoria and New South Wales, and as far north as Cape Tribulation in North Queensland (2007).
In 1998 and 2003 it was recorded singing, indicating that Migaloo is a male. This was confirmed in 2004 when tissue samples from Migaloo were analysed.
In August 2003 when he was 15–17 years, he was hit by a sailboat off Townsville. He now has a scar arcing diagonally across the left side of his back, halfway between his blowhole and dorsal fin.
Bahloo
In July 2008 another white whale was seen in Queensland waters. This one, named Bahloo after an Aboriginal moon spirit, was first seen swimming off the Gold Coast. Little is known about Bahloo other than that it has a few black spots on its head and tail.
Protecting whales and dolphins
Whales or dolphins may be declared as being of ‘special interest’ if they are at risk of harassment, injury or being killed.
Special interest whales and dolphins include animals that are colour-variants (e.g. totally white whales), young separated from their mothers, or individuals that are in a place that is readily accessible to the public.
Areas of special interest
Areas of special interest can also be declared to protect all whales and dolphins within a specified area (e.g. where they come to mate, calve, rest or where it is an important migratory corridor).
For whales and dolphins of special interest and in one of the areas of special interest (such as the Whitsundays) approach distances have been increased to reduce the likelihood of human disturbance.
Visit watching marine mammals for more information on how close you can get to whales.