National Geographic Live Speakers Series: Greg Marshall

Marine biologist Greg Marshall was scuba diving in Belize in 1986 when he saw a small fish hitching a ride from a shark simply by sucking onto its back. Marshall was inspired by what that smaller fish would get to witness by being attached to the shark, and began working on a camera system that could attach to an animal and record everything the animal saw. His invention, the Crittercam, has evolved much since it was first deployed in 1987, and nature-film fans and researchers continue to be dazzled by what the cameras capture. Marshall will speak at the State Theatre about the Crittercam.

CP: Explain to me a little about how the crittercam works.

GM: There are two types: the marine and the terrestrial incarnation. Most of the work we've done to date has been with the marine system. It is a system that incorporates all the video, audio, and environmental and geospatial data recording in the system. So you have to recover the system in order to get the data back since we're not able to transmit under water. So what that means is that not only does the housing have to contain all these components, it has to be rugged enough to go down to a thousand meters deep, then after it comes off the animal, float back to the surface for recovery. Then when it's sitting at the surface, a radio antenna pops out and transmits a signal, and we can triangulate on that signal and go out and pick the system up wherever it happens to be floating. We preprogram the system to come off at a certain time or under specific environmental conditions. With the terrestrial system, there are two versions. One is much akin to the marine system. The other is a video transmission system that is real time, so we can be three miles away observing what the animal is doing. Those systems are remote controlled, so we can get the video and audio and data transmission from up to three miles, and from five miles we can remotely control and interrogate the system.

CP: What animal have you not been able to study with a Crittercam that you would like to?

GM: To date the systems have been too large, in my mind, to work with dolphins. I think dolphin behavior in society is so interesting that it's going to be absolutely fascinating for the first time to be able to work with them with our newest generation system. These new systems are 2.25 inches in diameter, and now I think for the first time appropriate for an animal the size of a dolphin and as energetic as a dolphin.

CP: You've been recording with Crittercams for 20 years now. Does it ever get mundane or routine? Or do you find yourself constantly learning new things?

GM: It really is the latter. We're constantly improving our capabilities, we're constantly working with new animals, and we even learn from animals we've worked with over years. We did years of work with harbor seals in Nova Scotia off the coast of Canada, and every year we learn something new. We're amazed to see behaviors that we hadn't seen before and hadn't anticipated before. It really helped us construct a whole new sense of what they're doing during the mating season: how they're feeding, what they're feeding on, and where. To paraphrase a friend and colleague, the great thing about Crittercam is that it shows you things you don't know you don't know. And that proves to be the case with most of the animals we work with. We really don't know what these animals are doing out there. We're surprised all the time.

See Greg Marshall will discuss his work and innovations with Crittercam at the State Theatre Thursday.
Thu., Feb. 21, 7:30 p.m., 2008

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