for National Geographic News
This story is one of a series looking at National Geographic Crittercam research. Crittercam is a research instrument worn by wild animals and equipped with a video camera and other information-gathering equipment. Crittercam is used on animals both in the ocean and on land.
To learn more about the Crittercam's field test in Hawaii, tune in to the Crittercam: Pilot Whales episode on the National Geographic Channel in the United States on Friday, February 6 at 8:30 p.m. ET. Got a high-speed connection? Click here to watch previews of the Crittercam television documentaries on the National Geographic Channel Web site.
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The pilot whales are taking a time-out. Basking beneath the morning sun, they look like a raft of giant ebony logs, with just their dorsal fins and blowholes bobbing above gently lapping waters.
It would be easy for the boatloads of passing whale watchers to get the wrong impression, for these intelligent, powerfully built animals are far from idle. This is a well earned rest they're taking, having spent the pre-dawn hours chasing squid in the deeply shelving Pacific Ocean, off Hawaii's Kona coast. It was a successful night; one they are quietly digesting.
Until now, it would have taken a feat of the imagination to get a picture of what pilot whales get up to when diving beneath the waves. But with Crittercam, and other recent technology, scientists are beginning to shed more light on these mysterious sea mammals.
Kona is on the west side of Hawaii's Big Island. A popular tourist destination, the region also attracts many of the world's whales. As well as those magnificent behemoths, humpback and sperm whales, there are beaked, killer, melon-headed, and minke whales, to name a few.
Despite their names, some of these are really types of dolphin, as is the short-finned pilot whale (Globicephala macrorhynchus). Unlike its close relative, the long-finned pilot whale, they dwell in tropical and subtropical waters. Studies off northwest Africa found they favor areas where the seabed slopes steeply, creating strong currents and upwellings, which tend to support higher prey densities.
This might explain why short-finned pilot whales live off the Kona coast all yearunusual for this oceanic speciesfor the seas around Big Island, a volcanic outcrop, slope steeply down to around 2,000 meters (6,500 feet).
So a good location, too, for Robin Baird, biology fellow at Dalhousie University, Halifax, Nova Scotia, Canada, and local cetacean expert Dan McSweeney, of the Wild Whale Research Foundation, Hawaii, as they probe deeper into the pilot whales' lives.
Crittercam, attached via suction cups to the whales' backs, gave them an insight into the daytime diving behavior of these highly social animals which live in large pods of up to 200 animals. The ebb and flow of their daily routine appears to be dictated by the squid and fish they prey onspecies that lurk near the ocean floor during daylight hours. So this is a time mainly for bonding and lazing around.
"A lot of body contact is visible in the footage," said Baird. "It also confirmed that when the animals were near the surface they did not appear to be foraging, helping to prove that it is the deeper dives that function for foraging."