The scientific name for the Humpback whale is Megaptera novaeangliae, which means the 'great wing from New England'; the reference to the wings actually means their long pectoral fins, which are unique to Humpbacks. In fact their pectoral fins are almost a third of the length of their body and in some animals can be as long as 5 metres. The name 'humpback' comes from the way they 'hump' up their backs when they dive. Humpback whales can grow up to 16 metres in length and weigh up to 45 tonnes. It is estimated that they can live for up to 50 years. Calves are born up to five metres in length and weigh up to two tonnes. They drink up to 240 litres of milk a day and can gain almost 45 kilograms in weight every day that they are suckling. Some large baleen whales like the Blue whale can produce as much as 600 litres of milk per day.

Humpback males are known for singing. These haunting songs are thought to be associated with mating and breeding. Humpbacks in Australian waters spend summer feeding in Antarctica and during winter, travel to warmer waters along the Australian coast to breed and give birth. Some animals travel a round trip of almost 11,000 kilometres which is one of the longest mammal migrations in the world. Although Humpback whales are large animals they do have predators such as Killer whales and Great White sharks. Some times you can even see Killer whale teeth scars on the tails of Humpbacks that have been lucky to escape these cunning predators.

Figure A is a profile shot of a Humpback whale spy hopping - lifting its head out of the water.

Figure B shows the large fleshy plate on the whale's chin. This is called the chin plate. It is usually encrusted with many barnacles and is thought to be used as a weapon when the whale head butts other whales.

Humpbacks also have lots of round, squash ball sized lumps on their upper and lower jaw, and along their lips. These are called tubercles and are sensory nodes. Each node has a hair follicle attached to it, which measures about one and a half centimetres long. Scientists think that the tubercles allow the whale to sense variations in water temperature or pick up vibrations in the water. However its exact function is unknown.

Humpback whales belong to the group of whales classified as rorquals. The word rorqual is Scandinavian and it means 'furrow whale'. This is a direct reference to the large skin folds that are situated underneath the whale and run from just below the mouth all the way to the whale's belly. Humpback whales have 12 - 36 widely spaced throat grooves.

In figure A the whale has lifted its head out of the water and you can see the deep grooves in the skin underneath its chin.

In figure B, the whale is just about to push its head above the surface of the water and you can see the long skin folds in the white skin from it's chin right down to the neck. The purpose of the ventral pleats is to allow the whale's mouth to expand when it takes in tonnes of water when feeding, before filtering its food through the baleen plates as it forces the water out of its mouth.

Figure C shows the lower chin and throat of a whale expanding as it rolls on its side and feeds on a shoal of small fish.

When Humpback whales breathe they exhale air from their lungs at a speed in excess of 480 kilometres an hour. That's almost the same speed as a cruising jet airplane. When the whale exhales, the warm breath condensates as it hits the cooler surrounding air, and this is the telltale 'blow' which can shoot up as high as 4 to 5 metres into the air. Using a very high shutter speed on the camera you can clearly see the strength and height of the 'blow' in figures A & B.

After the blow the whale inhales air through its two large nostrils, this air exchange takes less than 2 seconds. Their lung capacity is enormous and at this moment they inhale almost 7 and a half thousand litres of air. Humpback whales store oxygen in their muscles and this helps them to stay submerged for sometimes up to an hour and they can dive as deep as two hundred metres. However this pales into comparison with the Sperm whale, which can dive to 3 kilometres, staying underwater for almost an hour and a half.

The dorsal fin of a Humpback whale is situated two thirds of the way down the whale's back. Like all whales and dolphins the dorsal fin is thought to be used to stabilise the animal as it swims through the water in the same way that a fin on a surfboard or the keel of a boat keeps their respective water craft stable in the water. Humpback whales have distinctive dorsal fins and they come in all sorts of shapes and sizes.

In figure A the dorsal fin is latticed with scars from a Killer whale that has attacked the Humpback. Figure B shows how different in shape that the fin can be in comparison to the fin in figure A.

And in figure C, this whale's dorsal fin is decorated with a number of barnacles that have hitched a ride on the skin. Again, this fin is also very different in shape compared to the other two.

Humpback whales have brown eyes. They do not have eyelids, but instead secrete a liquid which coats the eye and protects it from the salt water and other small marine debris. They have exceptionally good eyesight both above and underwater. The whale in figure A was stranded on a beach and was observed looking at all the human activity around it. It is thought that they can see up to 150 metres in clear water. Researchers suggest that although they have rods and cones in their eyes like us, it is thought that they do not have colour vision.

Humpback whales are very curious, figures B & C and often come up close to boats and have a good look. Often they will roll around on the surface of the water near a boat and expose one of their eyes to have a good look at what's going on.

Humpback whale skin colouration is black and white, with shades of grey. Most whales have a white belly and along their flanks leading up to their backs, the skin turns black. Although, there are some exceptions to the rule and some animals have black bellies and black backs. Conversely one whale rescued by the DEC whale rescue team was almost all white, with a very thin strip of black colouration running along its back. The skin is decorated with a variety of different markings.

Figure A shows a cluster of barnacles attached to the skin along the whale's pectoral fin. In figure B the flank of a whale shows a pattern of scarring and scrapes, possibly inflicted by fighting and jostling with other Humpback whales. C shows the whale's skin around its mouth. It is patterned with circular scars. These are from where barnacles had once been attached and have since fallen off.

Humpback whale genitals are situated inside their bodies in an area called the genital slit, situated just below their belly. Figures A & B show a Humpback rolling over and exposing its genital slit. For females, the mammary slits protect the nipples in skin folds & are situated either side of the genital slit. Humpback males also have a genital slit. Their penis is actually retracted up inside the slit, so are their testicles, unlike land mammals which are mainly external. This adaptation is to increase their hydrodynamics. If the penis was outside the body it would create a lot of

drag and slow the whale down as it swims through the water.

Figure C shows a view of the genital slit, on the top left, from underwater. It is thought that Humpback whales mate mostly subsurface. Other whales like Southern Right whales have been observed mating on the surface. Right whale males have the largest testicles of all the whale species, with each testicle weighing up to one thousand kilograms

Humpback whales are also classified as baleen whales. This is because they do not have teeth. Instead, they have long strands of baleen in their mouth, see figure A. Baleen is made out of keratin (the material that fingernails are made of) it is long and fibrous and is used like a sieve to trap food such as small crustacean-like animals called krill. Figure B shows a Humpback whale feeding, you can see inside the upper part of its mouth. The baleen plates are attached to the gum along the sides of the roof of the mouth. Although krill is the major prey item for Humpback

whales in the Southern Hemisphere, they also eat smaller fish and like most migratory animals are opportunistic feeders.

Figure C shows a Humpback whale feeding in Australian waters. The whale is lying on its side and scooping up hundreds of fish. You can see the fleeing school, bubbling on the surface at the top of the frame, desperately trying to escape.

The pectoral fins of a Humpback whale is the main distinguishing feature of this species. These fins are up to one third of the length of the animal's body and in some whales are almost five metres in length, no other whale has pectoral fins this size. The pectoral fins have bumps on the leading edge, these are called phalangic bumps and although their function is not entirely understood. It is thought that these bumps give their fins special hydrodynamic properties that aid in moving through the water and give the animals better control and maneuverability.

Like their tail, the fins are an excellent weapon and used to protect the whales from predators. They also use their pectoral fins in fights between themselves. Some whales with extensively damaged tails have been observed using their pectoral fins like oars, literally using them to row themselves through the water.

The peduncle is the part of the tail stock that extends from near the dorsal fin, right down to where the tail flukes begin. The peduncle is stocky and very muscular, which gives the whale the power to drive its body through the water.

In photo A you can see that the peduncle looks very thin and streamlined when seen from the top. But viewed from the side in photos B and C you get a true sense of its size and thickness. An adult Humpback can weigh

up to 45 tonnes and swim as fast as 15 kilometres per hour and when they breach, they can throw their whole bodies completely clear of the water, with as few as 3 beats of the peduncle and tail flukes. The muscles of a Humpback whale account for almost 40% of its total body weight and the bulk of these muscles can be found around the peduncle area, this equates to almost 12 tonnes of pure muscle.

The tail is the powerhouse of the Humpback whale and is used to propel it through the water. The tail and the two lobes either side called the flukes are positioned horizontally and they move up and down, unlike sharks and other fish, whose tail is vertical and propels them with a side to side motion. The whale's tail is its most powerful weapon and is used against predators such as sharks and Killer whales. In figure A look closely on the top right side of the tail you can see scars from a Killer whale's teeth where it has tried to latch on to the tail. A Humpback

whale's tail is unique to each individual and researchers use pictures of the ventral side of the tail as in figures A & B to identify individual animals.

The whale in figure C is very unique, in that the top and bottom of its tail is white, unlike most Humpback whales, where only the underneath of their tail is white.