Elephant Radio tracking
The areas to which the group of elephants being studied roamed were generally between 50 and 150km2 from one another. This is a relatively short distance, and made tracking them via a radio signal optimal. The VHF collar works by continuously emitting a broken beep (“beep, beep, beep”). Researchers then use antennae to track this sound within that predetermined vicinity. When they point the antennae to the direction in which the elephant is, the signal becomes much louder and clearer. However, the further away from the elephant they take the receptor, the fainter and less crisp the beeping is. This will eventually lead the scientists right up to the animal.
One of the chief disadvantages to this type of tracking is that the researchers need to be within close proximity to the elephant. This is about 3-4km in open veld and less than 3km in dense forests or shrubs. Like a television antennae, this method works better when the antennae is above the dense bushes and trees. So, scientists are frequently spotted perched atop a boulder or in the limbs of a tall tree, trying to get a better signal. This has to be done from 3 locations to get a “triangle of error”, which confines the possible location of the animal somewhat.
Clearly, then, this is a method that requires time, patience and expertise. It does not allow researchers, scientists and conservationists to answer many of the important questions regarding the unique needs of specific elephant populations, food- and water availability, and so on. It is for these main reasons that many are resorting to slightly more costly methods of tracking and researching elephants the world over.
Here is more about elephant tracking: http://www.savetheelephants.org/tracking.html