<P> Recent technologies have helped solve this problem . Some electronic tags give off repeating signals that are picked up by radio devices or satellites while other electronic tags could include archival tags (or data loggers). Scientists can track the locations and movement of the tagged animals without recapturing them using this RFID technology or satellites . These electronic tags can provide a great deal of data . Modern technologies are also smaller, minimizing the negative impact of the tag on the animal . </P> <P> Tracking an animal by radio telemetry involves two devices . Telemetry, in general, involves the use of a transmitter that is attached to an animal and sends out a signal in the form of radio waves, just as a radio station does . A scientist might place the transmitter around an animal's ankle, neck, wing, carapace, or dorsal fin . Alternatively, they may surgically implant it as internal radio transmitters have the advantage of remaining intact and functioning longer than traditional attachments, being protected from environmental variables and wear . A VHF receiver picks up the signal, just like a home radio picks up a station's signal . The receiver is usually in a truck, an ATV, or an airplane . To keep track of the signal, the scientist follows the animal using the receiver . This approach of using radio tracking can be used to track the animal manually but is also used when animals are equipped with other payloads . The receiver is used to home in on the animal to get the payload back . </P> <P> Another form of radio tracking that can be utilized, especially in the case of small bird migration, is the use of geolocators or "geologgers". This technology utilizes a light sensor that tracks the light - level data during regular intervals in order to determine a location based on the length of the day and the time of solar noon. While there are benefits and challenges with using this method of tracking, it is one of the only practical means of tracking small birds over long distances during migration . </P> <P> Passive integrated transponders (PIT) are another method of telemetry used to track the movements of a species Passive integrated transponders, or "PIT tags", are electronic tags that allow researchers to collect data from a specimen without the need to recapture and handle the animal . Data is captured and monitored via electronic interrogation antennae, which records the time and location of the individual . Pit tags are a humane method of tracking that has little risk of infection or mortality due to the limited contact necessary to monitor the specimens . They are also cost - efficient in that they can be used repeatedly should the need arise to remove the tag from the animal . </P>

Describe two applications of radio-tracking technology in endangered species management