Humpback Whales Feeding and Diet
The humpback whales (Megaptera novaeangliae) are a species of baleen whale. They are one of the larger rorqual species and adults range in length from 12–16 metres and weigh approximately 36,000 kilograms. They are known for their long pectoral fins and knobbly head. In this picture you will notice the size of a pectoral fin is larger than an adult human.
Humpback Whales males are wonderful producers of complex whale songs. I have heard these songs every time the hydrophone is placed in the water during the migration season.
Where Humpback Whales Feed
Humpback whales feed only in the cold waters of polar regions, this is conducted in the summer months and their diet consists of mainly krill and some small fish. Krill are small prawn like crustaceans. They are close to the bottom of the food chain and feed on phytoplankton. Interestingly krill have a biomass of over 500,000,000 tonnes, which is roughly twice as that of humans. Its a good thing as Humpbacks gorge them selves on the krill.
and the Bubble Net
Their migration to the warmer waters,tropical and sub tropical, see humpback whales travel long distances over large ocean crossings.They have been tracked with the use of GPS homing devices and shown to keep their course within 1 degree of last years track. Whilst on their migration to the breeding and birthing grounds the animals fast and do not eat until they arrive back in the Polar oceans. They exits on the fats stored over the last summers feeding. Humpbacks have more than one clever method of feeding but the bubble net is a joint effort from usually more than one whale. Starting at depth the whales blow bubbles out of their blowhole and swim in a circular pattern rising as they continue to blow bubbles. They entrap their prey in a "net" of bubbles, as the bubbles rise so do the whales as they surge through the ring of the bubble net and feast on the bait ball of fish created. There is a bit more strategy to this method.Using a crittercam attached to a whale's back, some whales were found to blow the bubbles, some dive deeper to drive fish toward the surface, and others herd prey into the net by vocalizing. The whales then suddenly swim upward through the "net", mouths agape, swallowing thousands of fish in one gulp. Plated grooves in the whale's mouth allow the creature to easily drain all the water initially taken in.
Bubble net feeding is not seen in the Australian waters. However Humpback whales are most definetly seen traveling along the coast line of Australia. If you would like to see the Humpback whales up close and personal contact Getaway Sailing on the Gold Coast for a private Whale Watching tour.