With fewer of their favourite prey of weddell seals resting on ice floes,
killer whales now have no choice but to target new prey. Crabeater seals.
Numbering 15 million, they're the most abundant marine mammal on earth.
But they are a far more dangerous target than a weddell seal.
Stronger... and more inclined to fight back.
But each member of this pod needs to eat a seal a day.
So the pressure is on to feed.
They're led by a matriarch who knows exactly what to do.
Living 100 years or more, she has plenty of hunting experience to draw upon.
With the ice floe having broken in two, the seals have become more vulnerable.
The matriarch now pushes the ice floe into open water to give their next wave maximum impact.
This requires teamwork and precision.
She makes her final calculations.
This seal has only one way of escaping death.
Unlike the less muscular weddell seal, the crabeater has the strength to hurl itself out of the water... just in time.
For the killer whales, it has been a significant waste of energy.
Their need to eat is now greater than ever.