Radio Tracking Basics
Radio tracking can be a very useful tool to help scientists study animals in
the wild. Among other things, radio tracking can help researchers determine a
species' home range, population density, and key habitat elements essential for
survival, such as places to live.
Just about anything can be tracked, and transmitters are made for animals as
small as beetles. Biologists have tracked many animals using this method,
including wolves, elephants, moose, deer, bats, foxes, rattlesnakes, turtles,
raccoons, fish, badgers, seals, and owls, among others.
Scientists try to tag and track as many individuals of a given species as they
can when learning about a population. When they capture an animal, they
document information about its size, weight, and other physical
characteristics. When tracking, they record such variables as the time of day,
habitat information, and how they located an animal.
Scientists usually use a frequency in the very-high-frequency (VHF) band—which comprises the wavelengths between about one yard and 11 yards—to track animals. That's
because animals don't naturally emit sounds in any frequencies in that band,
and it allows researchers to use a relatively small, hand-held antenna.
Radio tracking is not without its problems. It is difficult to tell the exact
location of an animal tracked by radio; whenever possible, users make a visual
sighting to confirm the quarry's position. Also, many systems will only track
for a couple of miles or fail to track at all if the creature slips into a
ravine or behind a ridge. In addition, the animal may move after its tracker
has determined its initial position.
Scientists can also use transmitters to collect information on other variables
about an animal, such as temperature, respiration, heart rate, life span in the
wild, and causes of death.