The UW system, called Encounternet, uses programmable digital tags that can send and receive pulses.
"Encounternet tags can monitor each other, so you can use them to study interactions among animals," said co-author John Burt, a UW affiliate professor of electrical engineering. "You can't even start to do that with other radio-tracking technology."
Other research groups are using the UW tags around the world. Researchers at the University of Windsor in Canada are using them to study mating behavior in Costa Rican long-tailed manikins; a researcher at Drexel University is using them to study the interaction between birds and army ants in Costa Rica; German researchers are putting the tags on sea lions in the Galapagos Islands to study their behavior as they pull up on beaches; and researchers in the Netherlands are studying the social behavior of great tits, a small woodland bird.
"It's a big topic right now, the idea that animals have social networks," Burt said. He has been working with field biologists for the last three years to deploy the tags.
"There are other tags that can do proximity logging, but they're all very big and for larger animals. None is as small as Encounternet or even near to it."
The smallest of the UW tags weighs less than 1 gram (0.035 ounces) and can be used on animals as light as 20 grams (less than an ounce), about the weight of a sparrow. Researchers attach the tags to birds with straps that degrade and harmlessly fall off after the battery dies. The tag records nearby pulses, and the signal strength gives an estimate of the other animal's distance.
A typical study using the system includes a few dozen tags and between 10 and 100 fixed base stations. When tagged animals pass a base station the data is transmitted wirelessly from the tag to the base station, and from there to the Internet. Researchers can also reprogram the tags remotely
|Contact: Hannah Hickey|
University of Washington