San Francisco
MARINE mammals are known for their intelligence, grace and sophisticated
behaviour. But they are not particularly famous for their skill at photography.
Nonetheless, a marine biologist in California has trained a pair of sea lions to
film whales and also assist in tagging the elusive beasts. If the plan works, it
will reveal a previously unexplored world of animal behaviour.
Studying the natural behaviour of whales has always been difficult. Aerial
photography, for instance, has revealed that they surface less often when divers
enter the water. Even if the whales were oblivious to the presence of humans,
Homo sapiens is hardly designed to follow them; whales can dive deeper,
surface more quickly and swim
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at high speed for hours. 鈥淎ny diver knows that when a whale gets going you
can鈥檛 keep up. That is why we know only about 5 per cent of what whales do,鈥�
says James Harvey, a marine biologist at the Moss Landing Marine Laboratories in
California.
So Harvey decided to take some of the problems of studying whales
out of human hands. He chose sea lions for the job because they are natural
consorts of many species of whale, and are relatively easy to train, transport
and care for. He enlisted the help of biologist Jenifer Hurley at Moss Landing
to re-educate a Navy-trained sea lion called Beaver, now 17 years old, and a
9-year-old female called Sake who used to perform at an amusement park.
After six years of training in tanks, Beaver and Sake will be ready for their
first assignment this autumn, during the humpback whale migration in nearby
Monterey Bay. Although the undersea cinematographers have grown accustomed to
wearing vests equipped with video cameras, filming will not be their immediate
task. Instead, they will help to tag the whales with radio transmitters. This is
normally done by firing a dart carrying a transmitter into the whale鈥檚 hide. But
biologists may have to wait hours on boats for whales to surface close enough to
insert the dart, and even then have trouble placing it where it will transmit
most effectively: exactly in the middle of the animal鈥檚 back.
But the sea lions are now ready to take on tagging duty. They have become
expert at swimming with a suction-cup tag in their mouth and, on command,
attaching it to a giant plastic coke bottle painted to look like a whale. 鈥淚t鈥檚
great, the sea lions can do it underwater, and put the tag exactly where we want
it to go,鈥� says Harvey.
If the trial planned for this autumn works, the researchers will teach the
animals a series of sound signals that will allow them to direct the flippered
photographers during film shoots. Harvey says that among the cues Beaver and
Sake will need to learn are 鈥渄o a complete circle around the animal鈥�, which is
important for determining the sex of a whale, and鈥攃rucial for the future
of the project鈥斺�漴eturn to ship with the camera鈥�. If Sake and Beaver
continue learning at their present rate, the team believes they will have
acquired these skills in about a year.
Bernd W眉rsig, a marine biologist at Texas A&M University in
Galveston, says the idea of using marine mammals as camera operators has been
floating around for years, but he says Harvey is the first person to come so
close to realising it. 鈥淭hese sea lions are so agile and such rapid swimmers,鈥�
he says. 鈥淚f it works, it opens up the potential of getting really great
诲补迟补.鈥�