One of the most delightful sights whilst travelling the east coast of Australia is the spout of a whale.
It is therefore shocking to learn that this magnificent animal has been hunted, murdered and slaughtered to within just 100 of its species !!!
Humpbacks are an endangered Species.
From the arrival of the Europeans in Australia during the late 1700’s onwards, the Humpback Whales were almost hunted to extinction – for products such as soap, oil, bone and food . . . A population of well over 60,000, plummeted to just 100 by the time commercial whaling was banned in 1986. The last whaling station in Byron Bay, New South Wales closed as recently as 1962, because so few whales could be found . . .
It was their migration habits; their slow cruising speed; the fact that they are surface travellers; and travel, mate and calve close to shore – that made them so vulnerable to human greed and cruelty.
Thankfully, the Humpback Whale is now protected throughout Australia.
The migration of the Humpback Whale is one of the longest migrations of the Animal Kingdom. With a cruising speed of approximately 7 km per hour, they travel from the freezing waters of Antarctica, to the relatively warm tropical and subtropical waters to mate and give birth to their young. Hence every year, some 16,000 Humpback Whales embark on a journey of up to 10,000 km from Antarctica’s feeding grounds, all the way to the tropical waters of the Great Barrier Reef off the north-east coast of Australia – and back.
Humpbacks get their name from the humped area of blubber situate anterior to their dorsal fin which is accentuated by the arching of their backs when the dive. A small dorsal fin is located almost two-thirds of the way down their back.
The Humpback is generally dark grey or black in colour, with white patches on its the belly, pectoral fins and on the underside of the tail (flukes). These unique black and white markings are unique to each individual Humpback, whereby no two are the same – such as a fingerprint on a human. It is this feature that aids researchers in identifying individuals as they migrate along the coast.
The long flippers (pectoral fins), which are generally 1/4 to 1/3 of the length of the entire whale, have bumps and are scalloped on the leading edge – unique to Humpbacks. It is important to consider that an adult Humpback is bigger and heavier than a city bus, yet remarkably agile when diving and turning. Could it be that part of the secret lies in the design its flippers ??? Most other Cetaceans have flippers with smooth leading edges, however, the Humpback is unique with its large bumps and scalloped edges. As the humpback swims, water flows over the bumps, breaking up into a multitude of vortices. Basically, this means that the ‘bumps’ channel the water flow and create turbulence. This flow provides the whale with more lift, allowing it to tilt its flippers at a severe angle without stalling – whilst also reducing drag. Perhaps this concept could revolutionise the future design of boat rudders, water turbines, windmills, and helicopter rotor blades ???
These ‘bumps’ and scallops are also present on the flukes (tail), but on the trailing edge . . .
As with all baleen whales, the male is slightly smaller than the female.
Humpbacks, being Rorquals, have distinctive broad ventral throat grooves, extending at least to their navels – some 14 to 35 in number.
Generally, their bodies are more robust than those of other rorquals.
The Humpback males produce a pattern of regular and predictable sounds that are generally referred to as a ‘whale song’ – often described as ‘haunting’ in nature. It is believed to be the longest song in the animal kingdom.
During migration, the male Humpback often ‘sings’ complex, lengthy and distinctive songs to communicate their presence to females in the hope to entice them to mate. They use syllables and rhyming phrases with a complex sequence of clicks, moans and eerie high-pitched wails that can last for a few moments to an hour.
The sounds range from canary-like chirps, to deep rumbling sounds that carry for hundreds of kilometres. The ‘songs’ subtly change every year, noting that different humpback populations do sing different songs.
During the breeding phase, being between Winter and Spring, the Humpbacks live in the warm, tropical regions for approximately 4 to 5 months. Whales do not mate for life nor do the males take any part in the upbringing of the young.
Humpbacks mate and calve between June to October of each year. The gestation period is between 11 to 12 months and each female typically bears a calf every 2 to 3 years.
The calves are born without blubber and therefore require the warm waters of the tropics to survive. They generally start life in shallow, protected waters, and, close to the surface. The newborn arrives tail first, which is normal for Cetaceans, and will instinctively swim to the surface within 10 seconds of its arrival – to take its first breath – helped by its mother, using her flippers. Within 30 minutes, the newborn is already able swim.
A newborn calf is some 4 to 5 m long and weighs approximately 900 kg at birth. The baby is nurtured with its mother’s milk, drinking anywhere between 200 and 600 litres of milk a day – in preparation for the long trip back to the feeding grounds. In the first three weeks of life, a calf can triple its size as the mother’s milk is as thick as tooth paste, and very high in fat – between 45% to 60%. The calf is generally weaned at around 11 months of age. The mother and calf can stay together for at least a year, sometimes 2 years.
Humpback whales reach puberty at 4 to 7 years of age, and maturity at 15 years. The females and males are ready to mate at the age of 5 to 7 years and have been known to live as long as 90 years.
Interestingly, the humpbacks of the Arctic Circle in the northern hemisphere also migrate towards the tropics and although both the populations mate in same waters, there is no crossbreeding due to the time difference of some six months – between the northward and southward convergences on the tropical waters . . .
Humpback whales breathe air at the surface of the water through 2 blowholes located near the top of their head. Adult Humpback’s usually swim to the surface to breathe every 10 to 15 minutes, but can remain submerged for up to 45 minutes. Humpback calves, however, need to surface to breathe every 3 to 5 minutes.
They spout or blow (breathe) approximately 1 to 2 times per minute at rest, and 4 to 8 times per minute after a deep dive. Their blow is a double stream of spray that rises 3 to 4 m above the surface of the water.
It is the spout or blow that often draws the attention of their presence . . .
Humpbacks are baleen whales which means that they do not have any teeth. They feed by filtering shrimp-like krill between 270 to 400 baleen plates which hang from the top jaw. They feed in Antarctic waters, but will also eat small fish and plankton during their migration south from their breeding grounds.
Interestingly, adult Humpbacks go without food during migration, which can last for around 5 months. During this time they rely solely on their fat reserves to fulfill their energy requirements . . .
Another distinctive element of the Humpback Whale is their playful acrobatics. Watching them is enchanting – their size and agility surreal.
All that embark on the privilege watching whales at play profess a life changing experience – to engage with such a gentle giant, experience their forgiveness and understanding – their all knowing . . .
It is inconceivable to comprehend how humanity could inflict such hurt and devastation upon them, and yet the Humpbacks remain inquisitive and trust us enough to approach the boats, all the while ensuring they do us no harm. If only we could honour them in the same way . . .
Above all, they maintain their traditions, and their fun. Some of their spectacular shows are described:
This spectacular sight where they quickly gain speed, launching their entire body out of the water, often twirling in the air, and hitting the water creating a tremendous splash and noise.
This manoeuvre is when a Humpback vertically rises above the ocean surface, most probably to observe or sense what is going on above water level. They are known to rise to a level allowing them to purposely eyeball whale watchers – perhaps it is their way of saying ‘Hello’?
Humpback’s often slap one or both of their enormous flippers (pectoral fins) against the ocean surface making a loud slapping noise. It is believed to be a signal of communication between whales.
A tail slap is when a Humpback raises it’s fluke (tail) out of the water and forcefully slaps it on the surface. This can be a repetitive behavior, which marine scientists believe is a warning communication for whales.
Male Humpback’s have been observed to head lunge towards and against each other during aggressive and competitive behavior . . .
A peduncle throw is one of the most uncommonly seen behaviors, mostly exhibited in aggression. It is when a Humpback powerfully throws the lower portion of its body sideways across the surface of the ocean.
On the other hand, the peduncle arch, often also called a ‘round out,’ is one of the most easily spotted behaviors of the Humpback, even though not much of the whale is visible, apart from the rounded part of the back skimming over the surface of the ocean as it prepares to dive . . .
Fluke Up Dive
A fluke (tail) up dive is characterised by an even amount of the tail upon the surface of the ocean. The Humpback is generally in an upside down upward arch, slowly rolling into a dive towards the ocean floor . . .