A bigger nose, a bigger bang: Size matters for ecoholocating toothed whales

Whales, dolphins, and porpoises have all evolved to use similar narrow beams of high intensity sound to echolocate prey

Date:  November 15, 2018

Source:  Aarhus University

Trying to find your lunch in the dark using a narrow flashlight to illuminate one place at a time may not seem like the most efficient way of foraging. However, if you replace light with sound, this seems to be exactly how the largest toothed predators on the planet find their food. A paper out this week in the journal Current Biology shows that whales, dolphins, and porpoises have all evolved to use similar narrow beams of high intensity sound to echolocate prey. Far from being inefficient, this highly focused sense may have helped them succeed as top predators in the world's oceans.

A new sense enabled toothed whales to succeed in diverse habitats

32 million years ago, the ancestors of toothed whales and baleen whales diverged as the ancestors of toothed whales -- including dolphins, porpoises and sperm whales -- evolved the ability to echolocate; to send out sound pulses and listen for the returning echoes from objects and prey in their environment. This new sense allowed these animals to navigate and find food in dark or murky waters, during the night, or at extreme depths. Since then, this evolutionary step has allowed these animals to occupy an amazing diversity of habitats, from shallow freshwater rivers to the great ocean deeps.

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