1 images Created 17 Feb 2013
Alaska Humpback Whales
In the summer months the fjords, bays, inlets and sounds of Southeast Alaska support a sizeable population of migrating humpback whales that feed on shoaling fish like Pacific herring and krill. These humpback whales are distinctive for their advanced cooperative feeding strategies, notably the deployment of large bubble nets and loud piercing calls to herd their prey. This may involve up to two dozen whales, but only one whale specialises in either blowing the bubble net or creating the herding call. It is one of the most spectacular feeding events that it is possible to see anywhere on earth and I became addicted to the surge of adrenaline that accompanied every feeding lunge.
It became like a gigantic game of cat and mouse keeping up with the whales and anticipating their feeding lunges. Sea birds often gave me clues but after many years of accompanying the whales I developed extra-sensory instincts for tuning into their underwater movements. I also used a hydrophone to track the feeding sequence. At first came the release of bubbles, like the sound of someone turning a tap on full; the whales are circling their prey and one of them is starting to create a cylinder of ascending bubbles to trap the fish. Then the loud, piercing feeding call that shakes my body to the core. The bubbles appear on the surface and I try to calculate the size of the bubble net and where the centre may be. The feeding call gets louder and louder, and seems to go up an octave, then I quickly brace myself for action to ensure that I’m not going to obstruct them and I’m positioned to take some photos. Suddenly the epicentre of the bubble net erupts with fish flashing out of the water like shards of broken glass and then the water becomes a boiling cauldron of large bubbles escaping from the gaping jaws of the rapidly ascending whales. Then the water explodes with a tightly packed formation of fully extended jaws, bristling baleen and the rippling pleats of their fully distended throats.
It became like a gigantic game of cat and mouse keeping up with the whales and anticipating their feeding lunges. Sea birds often gave me clues but after many years of accompanying the whales I developed extra-sensory instincts for tuning into their underwater movements. I also used a hydrophone to track the feeding sequence. At first came the release of bubbles, like the sound of someone turning a tap on full; the whales are circling their prey and one of them is starting to create a cylinder of ascending bubbles to trap the fish. Then the loud, piercing feeding call that shakes my body to the core. The bubbles appear on the surface and I try to calculate the size of the bubble net and where the centre may be. The feeding call gets louder and louder, and seems to go up an octave, then I quickly brace myself for action to ensure that I’m not going to obstruct them and I’m positioned to take some photos. Suddenly the epicentre of the bubble net erupts with fish flashing out of the water like shards of broken glass and then the water becomes a boiling cauldron of large bubbles escaping from the gaping jaws of the rapidly ascending whales. Then the water explodes with a tightly packed formation of fully extended jaws, bristling baleen and the rippling pleats of their fully distended throats.
