Thursday, September 24, 2020

A smiling whale makes a record deep dive

 The elusive Cuvier’s beaked whale, already known for its prowess as a diver, turns out to have even more staying power than scientists thought.

The Cuvier's beaked whale, whose deep dives can last an hour or more, typically spends only minutes at the sea surface before plunging back underwater. Credit: Todd Pusser/NPL

The champion diver among whales can stay underwater for more than 3½ hours — an unparalleled diving record for any mammal.

Cuvier's beaked whales (Ziphius cavirostris), which live in deep waters around the world, are capable of reaching depths of almost 3,000 metres when hunting for squid and other food. Scientists had previously estimated that these whales could hold their breath for around 30 minutes before exhausting their oxygen store. But observations among Cuvier’s whales foraging off the coast of North Carolina suggest they can dive for far longer.

Nicola Quick at Duke University in Beaufort, North Carolina, and her team fastened satellite-linked tags on 23 whales and obtained records from almost 3,700 deep dives over a 5-year period. The data reveal that the median duration of foraging dives was around a full hour, before the animal returned to the surface to recover.

One individual made two extreme dives of 2 hours 57 minutes, and 3 hours 42 minutes, respectively, which might represent the true limit of the species’ extraordinary diving capacity, the researchers say


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