for National Geographic News
Short-finned pilot whales off the Canary Islands race like cheetahs after prey over long distances in the deep Atlantic waters, new research reveals.
Like all whales, pilot whales need to come to the surface to breathe, but they can hold their breaths for extended periods.
Short-finned pilot whales are known to dive to more than 3,200 feet (1,000 meters), but their behavior in the deep ocean has been a mystery.
Researchers monitored the whales near Tenerife, the largest island in the Spanish-controlled archipelago (see map), by attaching tags to 23 of the animals with suction cups.
The tags recorded movement, sound, and depth for one day, after which they disconnected and floated to the surface for collection.
"We really wanted to know what whale behavior was like at depth," said study author Natacha Aguilar Soto, of the University of La Laguna in Tenerife.
"We expected deep-diving whales to maintain slow speeds to conserve oxygen so they could increase the time available to search and get their food."
Instead the team found that during most daytime dives, the whales sped up to an average of 19.2 feet (6 meters) a second, with top speeds reaching 28.8 feet (9 meters) a second just before reaching the deepest point of their dives.
The whales then were found to release a buzz with their biological sonar, as if locating something in front of them. Aguilar and colleagues believe the observations indicate that the whales were chasing after prey.
The study appears in an upcoming issue of the journal Animal Ecology.
Swimming speeds for other breath-holding animals such as seals, deep-diving birds, and dolphins have been measured at about 6.4 feet (2 meters) a second.
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