New Insights From Creatures' Perspective
Monday, October 29, 2007
Two decades ago, Greg Marshall was diving off the reefs of Belize studying queen conchs when he noticed a reef shark passing by with a remora clinging to its belly. The thought occurred to Marshall, who was then a graduate student in marine environmental science, that if a camera could be attached to a shark the way the parasitic fish was, he'd have a means to observe some of the most elusive creatures on Earth.
"It was one of those epiphanic moments in life," recalled Marshall, who now works as a scientist and filmmaker at National Geographic magazine. "I thought, 'I need to make it look like and feel like a remora.' "
Marshall has spent 20 years pursuing that vision: creating an animal-borne recorder known as Crittercam, which evolved into a remote-imaging program based at National Geographic that seeks to capture images, sound and data from the perspective of a variety of animals.
The first device that Marshall created in 1987 weighed more than six pounds; in its current incarnation, it weighs a little less than 1.5 pounds and is 2.25 inches in diameter. While it's not nearly as small as an iPhone, most sizable animals don't seem to mind it.
Since Crittercam's invention, researchers have attached the devices to more than 50 species of marine, terrestrial and flying creatures, including great white sharks, black bears and Hawaiian monk seals. More than 30 scientific groups in academia and government -- in agencies including the National Oceanic and Atmospheric Administration and the Agriculture Department -- use Marshall's invention to collect data and develop wildlife policy.
Over the past 15 years, the devices have produced a number of significant new insights, revealing, for instance, that black sea turtles off Baja California are omnivores rather than vegetarians, and that male harbor seals make a "bubbly growl" when defending their offshore territories.
"Crittercams are bringing a new dimension to NOAA research, because they help our scientists see the ecosystem through the eyes of the animal. We're able to go where the animal goes," said NOAA Administrator Conrad C. Lautenbacher. "Crittercams also help connect the public more directly with what is going on under water, putting them in touch with a rich environment that most people never see."
John Calambokidis, a marine biologist with Cascadia Research Collective, a nonprofit group that studies imperiled marine mammals, has used Crittercam to capture the sounds of blue whales, which make a "pulsing rumble" -- the loudest noise made by any animal on Earth -- to attract mates.
"Here's an animal that spends 90 to 95 percent of its time underwater," Calambokidis said. Without Crittercam, "I'd only get to study them while they're at the surface."
Between 1999 and 2004, Calambokidis and his colleagues attached Crittercams to whales 30 to 40 times off the coast of California and Mexico, capturing nearly 100 hours of video, sound and depth recordings. The equipment showed that blue whales were diving about 900 feet deep in an "up and down" pattern, he said, most likely as part of a feeding routine.
Just as important, the recorders captured the long, loud sound that male blue whales make when they are seeking a female whale.
"You are the whale," Calambokidis said, playing a video on his laptop that showed the whale's perspective as it emitted a sort of rhythmic noise, and bobbed up and down through the ocean before speeding off.