Because the wolves are rarely seen, one of the few ways biologists have to monitor (check on) their activities is to radio-track them.
Radio-tracking (also known as radio telemetry) has been used for many years to study wildlife. The collars used on wolves weigh a little over a pound. The main components (parts) are a battery and a transmitter which emits a signal on a specified frequency or channel.
To pick up this signal, biologists use a special receiver and an antenna. When the correct frequency is dialed in and the antenna is pointed toward the wolf, trackers hear a steady beeping signal the closer the wolf, the stronger the signal.
Some radio collars have the ability to emit different types of signals, depending on what the wolf is doing. For instance, if the wolf is active, the beeps might become more rapid. Most collars are equipped with a "mortality mode" the one signal biologists hate to hear. It only comes on when the collar has not moved for several hours, which means the wolf is no longer wearing the collar or the wolf has died.
To locate a wolf, the biologist stands with the antenna above his head and slowly turns it in a circle until he hears the signal. The direction the signal is coming from is marked on a map. The biologist then moves to another location (usually a mile or so away) and gets a second bearing on the wolf. The wolf's location is approximately where the bearings intersect (cross) on a map.
Ground tracking can be very difficult and is often inaccurate. Signals can be interrupted by hills and trees. Another disadvantage is that the tracker has to be relatively close to the wolf to pick up the signal usually within two or three miles.
A much more reliable system of radio-tracking (also more expensive) is to track by air. The antennas are attached outside the airplane and the biologist sits next to the pilot and listens for the signal on a headset attached to the receiver.
Tracking by air has many advantages over ground tracking:
Signal interference is much less because you are above
the hills and trees; on a clear day, the signal can
be picked up from as far away as ten miles; locations
are more accurate because you can fly right over the
wolf and pinpoint where it is.
Christopher Lucash is the supervising biologist working with the red wolves in the Great Smoky Mountains National Park.