How does a predator go about eating an eight-legged prey almost as big as itself?

With no hands, how can one get the better of a live eight-armed prey measuring over one metre long equipped with suction cups and capable of suffocating its attacker? Is this the job of a great chef or a predator’s worst nightmare? In a recent study, behavioural ecologist Kate Sprogis (University of Murdoch, Australia) and her colleagues describe in detail for the first time a few of the techniques used by the Indo-Pacific bottlenose dolphin to safely prey upon the octopus, an immense and dangerous animal.

Predators wishing to feed on large live prey that cannot be eaten whole must develop techniques to control and transform their prey before ingesting them. Various techniques have been developed, notably by crocodiles, alligators, sea leopards and toothed whales to break their prey into pieces and tenderize their flesh. For example, killer whales shake the seals and belugas that they catch and toss dolphins and stingrays into the air. Bottlenose dolphins, on the other hand, shake and throw fish about to break it into small chunks and soften it before consumption. These dolphins have also developed a complex technique to break the giant cuttlefish into pieces using a sequence of steps to remove the head, ink and cuttlebone.

In the study conducted by Kate Sprogis and her colleagues, researchers observed 45 episodes of Indo-Pacific bottlenose dolphins (Tursiops aduncus) handling octopus. Two different techniques were observed. In the first technique, the dolphin arches and raises its body out of the water while it holds the octopus in its jaws and slaps it forcefully on the water surface. In the second technique, instead of keeping its jaws closed when it arches and lifts its body and the octopus out of the water, the dolphin opens its mouth, throwing the octopus into the air, often over several metres. The dolphin then recovers the octopus and continues to shake it and slap it on the water surface (usually 10 to 15 times). Researchers suggest that the dolphin behaves this way to remove the octopus’ head and mantle, soften its flesh, ensure that its arms are inactive and separate the animal into sections to facilitate ingestion.