It doesn’t matter how many times you’ve seen a Humpback breach, you still can’t help but to stop in awe of these enormous, majestic and mystical creatures! With adults measuring 12-16 meters in length and weighing in at a whopping 30,000kg there is still something so streamline and weightless about the way they move through the ocean.
Humpback whales (Megaptera novaeangliae) have a life expectancy of at least 48 years, with sexual maturity being reached between four and eight years (average five years). These whales have a gestation of 11-12 months and once their calves are born, they breast feed for a further 10-12 months. Calves become independent between one and five years after birth (sometimes even longer), with a two and a half year average calving interval. This just highlights the immense commitment from these mothers to raise their young.
At the moment hikers on the Cape to Cape Track are experiencing the peak period of migration for population 8 (Group D) of the 15 populations of Humpback’s from around the world. Although this populations was hunted to the brink of extinction throughout the 1950’s and 1960’s, they are steadily recovering at a rate of approximately 11% per year with current estimates placing population 8 as the largest aggregation of Humpbacks in the world nearing 50,000 individuals.
Every year, these enchanting creatures take the incredible journey from their feeding grounds in the nutrient rich waters of Antarctica between (70° E and 130° E) all the way up to their breeding area in Australia’s north-west – as far as Camden Sound. The congregation leaves Antarctica around May in an orderly fashion dependent on sex and reproductive status. On their journey to their breeding grounds, lactating females with their yearlings head out first, followed by immature males and females with mature males, resting females and pregnant females making up the tail end charlie aggregation. On their journey south, mixed females, immature males and females leave first, followed by mature males and finally females with calves in early lactation follow.
The whales travel an incredible 9,000kms on their return journey and unbelievably they very rarely feed throughout the entire migration. They tend to stay within 20kms of the coast in waters of depths up to 200m. On their way back to their feeding ground in Antarctica, they hitch a ride in the Leeuwin Current – boosting their speed to approximately 10km/h which would be a massive help for a lactating mother on an empty stomach. The whales stop for a rest at four different locations on their journey, including Augusta, Geographe Bay, Shark Bay and the southern Kimberley region. We are very lucky to have the whales spending a little extra time on either side of the Cape and if you are in the area during the migration, we definitely recommend taking a charter to get up, close and personal with these gentle giants!