The idea of an “animal tracking bracelet” often surfaces from public curiosity, but the technology used to monitor wildlife globally is far more sophisticated than a simple wristband. Scientists and conservationists employ a diverse array of highly specialized devices, including collars, tags, and internal implants, to gather data on animal movements and behavior. This technology is fundamental to modern ecological research and species protection efforts, providing unprecedented insights that transform conservation approaches.
Clarifying the Terminology: Collars, Tags, and Implants
The devices used in animal monitoring are engineered to be minimally invasive and species-specific. For large terrestrial mammals like elephants or big cats, a Global Positioning System (GPS) collar is the most common form. These collars fit securely around the neck and contain the necessary electronics and battery power for long-term deployment.
Smaller animals or those with unsuitable neck shapes are fitted with alternative devices. Birds often carry small, lightweight harness packs or leg bands. Marine animals, such as sea turtles or whales, have satellite tags attached to their shells or dorsal fins.
For identification purposes, Passive Integrated Transponder (PIT) tags are used. These microchips, the size of a grain of rice, can be surgically implanted under the skin of many species, including amphibians and small mammals. These microchips only contain a unique ID number for local scanning and cannot provide real-time location tracking like an external GPS unit.
The Science Behind Animal Location Tracking
The location data collected relies on three primary technological systems, each suited for different environments and research needs.
Global Positioning System (GPS)
GPS is frequently used, where the device on the animal receives signals from multiple orbiting satellites. By measuring the time it takes for these signals to arrive, the device precisely calculates its position, often within a few meters of accuracy. This data is then stored on the device or transmitted to researchers.
Argos Satellite System
For transmitting data, some devices use satellite systems like Argos, which is effective for animals in remote oceanic or polar regions where other networks are unavailable. The Argos system uses the Doppler shift in the tag’s radio signal to estimate the animal’s location as the satellite passes overhead. This location is then relayed to a ground station. The location resolution from Argos is typically less fine than GPS, ranging from 150 to 1,000 meters.
Radio Telemetry
Radio Telemetry uses Very High Frequency (VHF) or Ultra High Frequency (UHF) radio signals for close-range tracking. The tag emits a pulsed signal, and researchers use a handheld antenna and receiver to physically follow the animal or triangulate its position. In areas with mobile network coverage, some trackers transmit their GPS data using the cellular network.
Essential Applications in Conservation
The data collected from tracking devices provides scientists with a detailed ecological roadmap for conservation.
Habitat and Movement Mapping
Monitoring migration routes and corridors is a primary application, as tracking data reveals the exact paths animals take between seasonal habitats. This information is critical for establishing protected corridors and mitigating human-wildlife conflict. Data from these devices also helps identify critical habitats, such as specific feeding grounds, breeding sites, or den locations, which can then be prioritized for protection.
For example, GPS collars on lions have precisely mapped their territories, helping design reserves that encompass their entire home range. Tracking also allows for the continuous study of animal behavior, providing insights into daily routines, social dynamics, and the impact of environmental changes on their movements.
Anti-Poaching Efforts
The technology is also deployed in direct anti-poaching efforts, offering a safeguard for highly endangered species. Some transmitters fitted into the horns of rhinos are equipped with motion sensors. These sensors trigger an alarm if the animal is stationary for an unnatural amount of time, suggesting a poaching incident. Real-time tracking allows rangers to monitor protected animals remotely and respond quickly to investigate abnormal movements or sudden lack of movement.