What is a humpback whale? The humpback whale (Megaptera novaeangliae) is the fifth largest of the great whales. Its scientific name comes from the Greek word mega meaning ‘great' and pteron meaning ‘a wing', because their large front flippers can reach a length of five metres, about one-third of their entire body length! They are named humpbacks because of the distinct ‘hump' that shows as the whale arches its back when it dives.

What do they look like? Humpbacks are ‘rorquals', whales which have distinctive throat grooves. They also have knobs on their heads known as ‘tubercles', each of which has a long coarse hair growing from its centre which is believed to act as a sensor. They have very long flippers (more correctly known as 'pectoral fins') with knobs on the front edge, and a humped dorsal fin. They are blackish, with white undersides and sides. The underside of the tail fluke is usually white with black patterning, which is unique to each humpback, like a fingerprint, so can be used to identify individual whales! Males average 14.6 metres and females 15.2 metres long. The maximum length is 18 metres and a mature adult may weigh up to 45 tonnes. Humpback whales have a life expectancy of 45 to 50 years.

Vision courtesy of MIRG Australia (www.mirg.org.au)/Blue Office Productions

Graphic : Location Map of Humpback Whales in Western Australia Where do they live? Humpback whales are found in all of the world's oceans, although they generally prefer near-shore and near-island habitats for both feeding and breeding. From June to July the Australian humpback whales migrate northwards to their tropical calving grounds in the Kimberley (their bedroom) and between September and November they begin travelling south to their feeding grounds in Antarctic (their kitchen). In 2013, the State Government created the jointly managed Lalang-garram / Camden Sound Marine Park under its Kimberley Science and Conservation Strategy to protect the largest humpback whale nursery in the southern hemisphere. During their southerly migration you can sometimes see these beautiful animals from the shore, as they pass along the WA coast including through the Montebello Islands Marine Park, Ningaloo Marine Park, Shark Bay Marine Park, Jurien Bay Marine Park, Marmion Marine Park and Ngari Capes Marine Park (lying between Busselton and Augusta). As they are often accompanied by their calves on the southern migration, they tend to stay much closer to shore than they do when heading north.

What they eat and how: Humpbacks are ‘baleen' whales, so instead of teeth they have 270-400 baleen plates which hang from the top jaw. They feed by taking big gulps of water and filtering shrimp-like krill and small fish between these plates. Humpbacks can consume nearly one tonne of food each day. Humpbacks use a hunting technique known as ‘bubble netting'. They swim in a spiral underneath a school of fish or krill blowing lots of bubbles. This creates a net of bubbles that traps a giant mass of krill. They then swim up the centre with their mouths open and have a huge feast on their favourite food.

Threats: In the past, humpback whales were heavily exploited by commercial whalers all around the world, hunted for their oil, meat and whalebone. Hunting was banned in 1963 after the species became nearly extinct. In 2007, the Japanese proposed to resume killing the humpback for so-called ‘scientific purposes', but gave them a last-minute reprieve. Other threats to humpback whales include them ingesting plastic, which accumulates in their gut and leads to a slow death, and becoming entangled in crayfish lines and pots. Supported by the Department of Parks and Wildlife, the Western Rock Lobster Council has introduced a Code of Practice to help reduce whale entanglements. Natural predators include killer whales which prey on the young humpback calves.

Behaviour: Humpbacks travel in groups known as pods. When in a playful mood, they may put on spectacular displays of breaching, rolling, spyhopping, slapping their pectoral fins and generally having a ‘whale' of a time. During the breeding season, the humpback males are known for singing the longest and most complex songs in the animal kingdom. An adult humpback's two lungs, each the size of a small car, are emptied and refilled in less than two seconds. As it surfaces, the humpback exhales through two blowholes on the top of its head. The air is expelled and cooled so rapidly that it forms a distinctive cloud, which is often mistaken for water!

Breeding and caring for young: After a 12 month pregnancy, calves are born five metres long and weighing about 1.5 tonnes. They drink around 240 litres of milk per day and the suckling calf can gain more than 45 kilograms a day during the first few weeks of its life. Nursing ends at about 11 months, when the calf can be up to nine metres long.

Conservation status: Humpback whales are threatened and specially protected under the Wildlife Conservation Act.

How you can protect the humpback whale: Follow the whale watchers code. Boats should not approach closer than 100 metres to a whale, a vessel should not separate a group or mother and calf and, if you are in the water and a whale approaches, you must stay at least 30 metres from the whale. If you should spot a whale that is stranded or entangled in rope or fishing gear call the Wildcare Helpline so the department's specially trained staff can help the animal.