Have you ever wondered how wildlife biologists know some of the information they do, such as what types of vegetation a certain animal prefers, or how large an area that animal needs to survive? Well, these questions and many more have been addressed using radiotelemetry, a powerful tool wildlife biologists began using in the 1970s. Radiotelemetry allows biologists to detect the location of a given animal to a relatively small area, sometimes within an area of a few feet. It is an important method for determining habitat use, home range estimates, survival, production and behavior. This technology allows researchers to observe from a distance, minimizing the disturbance to an animal and its surroundings. This tool can be used to track a wide variety of species, ranging from small fish to whales and mice to elephants.
Radiotelemetry is made up of three components: the transmitter, receiver and antenna. The transmitter is located on the animal. This component sends a signal that is picked up by the antenna, which is connected to the receiver. Antennas can be carried by hand, mounted on vehicles such as trucks and aircraft or mounted on stationary towers. Receivers translate the signal so it can be heard in the field or converted into data that can be analyzed later. Without a receiver, the transmitter's signal cannot be detected. Transmitters range in size from just a few ounces up to several pounds, and their ability to transmit signals can range from yards (e.g., lizards) to miles (e.g., deer). Some larger transmitters, such as those used on deer, have the ability to transmit a signal that is received by satellites, enabling the researcher to locate the animal from the comfort of his or her office. Transmitters are capable of sending out different signal rates to communicate different things. For example, these signals can tell the researcher if the animal is alive or dead or what temperature the animal is experiencing. Transmitters can cost from several hundred dollars (e.g., quail) to several thousand dollars (e.g., GPS collars for deer) each. Birds can carry collar or backpack transmitters that weigh just a few ounces. White-tailed deer are usually fitted with collars that weigh 1 to 2 pounds.
Radiotelemetry has enabled wildlife biologists to unravel some of nature's secrets, which would otherwise go undiscovered. This technology has often enabled information to be gathered without a researcher even being present to observe the specific animal. Information can be gathered 24 hours a day and collected in terrain that humans have difficulties accessing, such as the depths of the ocean or high in the Rocky Mountains. As the technology advances, the amount of information gathered will grow, leading to new discoveries.