for National Geographic News
Crittercam's latest evolution has been from sea to land, thanks to the work of its inventor, Greg Marshall, and his Remote Imaging team. This new generation of units will attempt to unlock the secrets of terrestrial animals and the environments they call home.
Unlike its marine sisters, Terrestrial Crittercam uses live transmissions to send data back in "real time." Visual and audio information is relayed back to a research team's base camp via radio transmitter for observation and recording. By sending out a radio "ping," researchers can request when and for how long they want to receive transmissions.
When the study period is over or battery power has been consumed, the Crittercam unit can be released and located by radio transmission as well. This mechanism also ensures that the unit can be released at a moment's notice should the subject animal be troubled by it.
Live transmission is a boon to researchers using Terrestrial Crittercam, giving them instant feedback on how the system is functioning and up-to-the-minute information on the subject itself. This technology avoids the often-harrowing data recovery measures necessary with marine Crittercams, which record within the unit and must be relocated and recovered before any data is received.
Marine researchers certainly would have it differently if they could, but video transmissions don't travel well through water, explained Remote Imaging's supervising producer Birgit Buhleier, requiring information to be recorded for later playback.
In addition to AV information, each unit measures two other critical factors: internal system temperature and battery strength. These factors, in turn, shape the physical design of each system, which is custom fitted to the specific animal being studied.
Battery power is of primary concern, due to power-hungry video transmission requirements, but so is building a system that will not hamper the device's wearer. By only requesting transmissions at intermittent intervals rather than continuous transmissions, battery power is conserved and thereby system size kept to a minimum. Both collars for larger animals and harnesses for smaller ones have been designed to carry Crittercam systems.
Thus far, Terrestrial Crittercam has been tested on the grizzly bear, lion, hyena, jaguar, eagle, domestic dog (in preparation for the wolf), and domestic cat (for future studies on lynx). These animals were chosen for their physical robustness and because opportunities were available to test systems on them in captivity under advisement from knowledgeable staff.
Having as little impact as possible is a prime objective, so critically endangered or fragile species, or young animals, are being avoided until Terrestrial Crittercam has been developed and refined further. While the system has room to include four or five more sensors, it could mean more wires that complicate wearing the device. So developers plan to move forward cautiously, giving heavy weight to keeping the device light and unencumbered.
Remote Imaging design engineer Dr. David Rasch summed things up this way: "We want to make sure we're part of the solution, not creating another problem for the animal."
Of course, some design worries seem to take care of themselves, thanks in part to its wearer. Take, for example, the challenge of keeping the camera lens cleansomething that's not a worry with marine systems.
"We were trying to come up with all sorts of win-screen wiper gadgets and things like that," said Rasch. "But when we put the camera on the lion in Kenya, the lion actually groomed itself and cleaned the camera lens for us."
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