There is a lot of mystery that surmounts the migration of Oceania’s Humpback whales! And also, their final destination in Antarctica. Indeed, it is something that has continued to remain shrouded in mystery for long now!
The humpback whales never miss a migration cycle. Whale watchers witness this every year on the east coast of Australia. To start from the beginning, Australian humpback whales spend the entire summer feeding on small fish and krill in Antarctica. According to marine biologists, the whales start their migration, 10,000-11,000 km towards the north, around the month of June.
Younger male whales lead the procession, while the mothers and calves follow behind as they are the last ones to arrive in the northern waters of the east coast. This is because migration allows whales to be in more subtropical weather where they can mate. Remember that summers around the world, between May, June, and July, are winters in Australia. Every year, whales travel here to give birth to calves too. Indeed, there are many facts that support that whales do have graveyards!
The humpback whale goes as far towards the northern area as the Coral Sea and Cairns. Whale watchers talk of frequent sightings near the Whitsunday Islands, the Moreton Bay, and Hervey Bay. The thriving whale watching industry has developed for 18 years now, thanks to these whale migrations. The female whales, in particular, make use of the protected bays to stop, feed their calves, and fatten them up before they have to head to Antarctica, which is freezing. The whales also migrate to bays along Pittwater Bay, Sydney Harbour, and New South Wales. They then commence their trip back south in late July and August, with most whales leaving the Queensland area in the middle of November. This migration is never easy; therefore, only the whales and calves in healthy condition can make the journey. On top of that, the trip is not easy as there are predators on the lookout for these beasts as they serve as their food source.
The truth is that whales are not safe wherever they are. They make the trip along the east coast to escape Antarctica’s frozen waters in winters, and even so, Japanese whalers have set-up camp for hunting whales. The other dangers to a humpback whale are the Orcas. Orcas are known to prefer eating the tongues of whales. Drag marks of the Orca are seen on the tails of many whales that make it through their migration. But that is not all; sharks are known as predators of whales too. The Great Whites migrate the same time whales do, by following groups of whales and looking for their weakest link, which would make for easy prey.
How do you identify the humpback whales?
Some of the whales can be identified by their surfacing, blow, and diving characteristics. Interestingly, the humpback whales can be effectively identified by the trailing and underside edge of their tail flukes. Just as you see your finger point, each for the humpback whales can be different in appearance. You can see the patterns of white and black pigmentations on their underside if the flukes. The tails are considered to be unique for each of such whales.
Tiger sharks are commonly found in tropical waters. A number of these usually bite the whale so that as its swims and bleeds, more sharks start arriving to attack it. However, Orcas are not that common here. A humpback whale might also be struck by ships while migrating. Whales usually get tangled in fishing gear or get stuck in the cray pot ropes. The ships’ propellers may even scratch the skin of a whale.
What is not a mystery anymore- some finding in 2020 has given a new path for research in this field
In the year 2020. Scientists say that they have cracked the enigma of why the whales actually migrate! Indeed, the humpback whales are known to sing a really different tune since their existence. Interestingly, the male humpbacks migrating along the east coast channels have really stunned all of us, more because they abandon their signature mating song. They are known to adopt a fresh and new tune from a small group of visiting Indian Ocean whales.
It is not wrong to say that apart from the different aspects of confronting research for the humpback whales, there is more to the picture! Scientists have long wondered about the baleens- the blues and the humpbacks travel up to 18,840 every year. And that too when they are migrating along their feeding grounds in warmer, tropical seas and polar waters. Previously, it was concluded and thought that the humpbacks, after feeding in the Antarctic or Arctic, traveled to large distances to give birth far away from their known predators. But, is it so?
Indeed, to find out the real reason for this case of the humpbacks’ migration, research led by Robert Pitman, a marine ecologist, has recently deployed 52 satellite tags on the different types of killer whales that usually inhabit the Antarctic waters. After tracking over some eight southern summers, there is an observation that was not expected by lots of researchers. They found that some of the humpback’s travelled all along 9400 km to the western south Atlantic Ocean, and the round trip was only 42 days! Yes, that is astonishing as a fact! And more to it is they did not travel such kilometers to give birth! The photographs that have been revealed by the team says a completely different story. The pictures reveal that the existence of the killer whales in the Antarctic waters, indeed, strike the feed-in-the cold, breed-in-the-warmth hypothesis!
In the research, it was also known that the humpbacks, like the humans, shed their outer skin cells in a continuous fashion. In a stance, Pitman says, “You can track humpback whales migrating up Australia’s eastern coast just by following the trail of raining epidermal cells they’re shedding.” Interestingly, in the cold regions like the Antarctic, the whales are apparently not able to molt. Instead of that process, it is seen that they build up a thick, yellow film of microscopic layers like diatoms on their skin. Indeed, if the diatoms’ concentration is greater than a certain range, it can also potentially accumulate harmful bacteria on the skin surface. It may adversely affect the humpbacks for their life!
What does that yellow-skin mean for the researchers?
There was yet another explanation made in the year 2012, and it talked about the whales’ yellow skin, especially the killer whales. The explanation said that killer whales usually could divert flow away from their skin juts to conserve body heat in cold Antarctic waters. This fact, in turn, can be related to the slow regeneration of the skin cells and ultimately drives them to warmer waters. It is then when we can say that the metabolism rate or their molting ratchets up considerably!
If you see it in brief, you will find numerous convincing arguments made by the scientists for the killer whales. But at the same time, there are different perspectives, so doubts do linger on whether this idea applies to all the whales’ species.
The bottom line
Still, we can find no such substantial evidence that speaks for the humpbacks’ convincing aspect and their migration. We duly acknowledge and admire the recent studies by different researchers and scientists for having the upper hand in investigating the migration aspects of the killer whales. As a part of the conclusion, it can be that one of the potential reasons for migrating to the tropical warmer areas and the colder polar regions could be to maintain and all about healthy skin! Get this idea to work for your curiosity to deal with better research shortly for the humpbacks and killer whales!