The Humpback Whale is world famous for their extraordinary surface activity and epic migrations undertaken every year for the survival of the next generation. Western Australia is proudly home to the largest known population of Humpback Whales in the world with over 45,000 individuals and growing every year! The warm waters of the Kimberley region are host to an enormous nursery ground as the female Humpbacks travel north every winter to give birth and raise their precious calves. The males will of course follow and the entire Western Australian coastline comes alive with the activity and energy of thousands of Humpback Whales on the epic migration path.
The best time to see the Humpback Whales in Western Australia is during their northern migration in late May to August every year in Augusta and on their southern migration during September to December from Perth. The whales round trip from the summer feeding grounds of Antarctica, to the winter nursery grounds of the Kimberley and back again is an incredible 13,000 kilometre round journey. One of the longest migrations of any mammal on the planet and they achieve this journey each and every year throughout their lifetime. Initially calves must be raised in a warm, safe environment to ensure a healthy start to life and the Humpbacks are bound by the desire to ensure survival of the next generation and go above and beyond to find the perfect nursery grounds.
Incredibly, the Humpback Whales of Western Australia only feed during their time in Antarctica over the summer months. During the rest of their time migrating north and then south again they rely on their fat reserves to get through. It is an extreme type of fasting as the whales are at their busiest competing, migrating, giving birth and protecting calves. The reason for this lack of feeding is simply a timing and energy issue, there is not enough easily accessible food along the coastline for the migrating Humpbacks. They are also time poor on these journeys, a female cannot leave her calf to go look for food and a male misses out on opportunities to mate if he is too busy foraging.
The only time we have witnessed foraging behaviour off the WA coastline is when juveniles, like most hungry teenagers, find a suitable snack and begin to forage having more time to do so than the mature age breeding adults. Due to the lack of food and high energy expenditure, Humpbacks can lose up to a third of their body weight by the time they return to Antarctica. Thankfully, trillions of krill are awaiting the hungry Humpbacks who will feed on 1+ tonne per day throughout summer.
Humpback Whales are also renowned for their surface activity such as breaching, tail lobbing and pec slapping. The sound this creates is a fantastic means of communication and this surface activity is actually a way the whales can communicate to each other over a large or short distance, the Language of the Whales.
They only have two main predators in their natural environment which are Orca and Sharks. The Orca can be a real problem for the calves and juveniles, but thankfully the calves are always protected by mum and juveniles will often follow the crowd to ensure they keep close to the bigger, mature adults that Orca are less likely to approach. Sharks can be a nuisance, they don’t tend to approach healthy whales but will linger and follow them should they notice the whale is injured or unwell. Overall, the Humpbacks are very comfortable in their environment and even when approached by predators like sharks or orca they will respond quickly and bravely.
They are big, beautiful whales and we are privileged in Western Australia to spend 6 months of our year observing them along our coastline on their epic migration. Humpback Whale numbers around the world are on the increase and within Australian waters we are seeing an incredible resurgence of the population as thousands of calves are born each and every year. A bright future is ahead for the Australian Humpback Whales and it is important to ensure we continue to learn about them.