Wildlife Tracking: The Technology Revealing How Animals Move Through the World

Wildlife tracking — the use of electronic tags, collars, and implants to monitor the movements of individual animals — has transformed our understanding of how animals use space, how they navigate, how they respond to environmental change, and how they interact with each other and with humans. The first radio tracking studies of the 1950s — which required a researcher on the ground with a directional antenna to detect signals from a transmitter attached to an animal — have given way to GPS collars that record an animal's position every few minutes with metre-level accuracy and transmit the data by satellite to researchers anywhere in the world. The movement data generated by modern tracking technology has revealed patterns of animal behaviour — migratory routes, home range dynamics, predator-prey interactions, responses to landscape features — that could not have been imagined by the naturalists who first began systematic wildlife observation.

GPS Collaring and Satellite Tracking

Modern GPS collars represent the most powerful tool in the wildlife tracking toolkit. A GPS collar worn by a lion, elephant, wolf, or whale records the animal's precise geographic coordinates at programmed intervals — typically every hour, but as frequently as every minute in high-resolution studies — and either stores the data for later download or transmits it in near-real-time via satellite or mobile network. The data generated by GPS collaring reveals the detailed movement ecology of individual animals: their daily activity patterns, the boundaries and structure of their home ranges, their responses to seasonal resource availability, their movements in relation to roads, settlements, and other human infrastructure, and their interactions with other tracked individuals. When multiple animals in a population are simultaneously tracked, the data provides a picture of social organisation and landscape use that no amount of field observation could generate.

Acoustic Telemetry for Aquatic Species

For fish, turtles, sharks, and marine mammals — animals that spend their lives in water and cannot carry GPS tags that require line-of-sight to satellites — acoustic telemetry provides an equivalent tracking capability. Acoustic tags, surgically implanted or attached externally, emit coded ultrasonic pulses that are detected by underwater receivers deployed in arrays throughout rivers, estuaries, and coastal areas. The array of receivers — which may number thousands in large-scale collaborative monitoring networks like FACT (Florida Atlantic Coast Telemetry) or OTN (Ocean Tracking Network) — records the time and identity code of each tag detection, allowing the reconstruction of fish movement paths through the monitored area. Acoustic telemetry has transformed our understanding of fish migration, habitat use, spawning movements, and mortality rates in species that were previously nearly impossible to track.

GPS Biologging — Revolution in Movement Ecology

The miniaturisation of GPS technology and the development of satellite data transmission systems have transformed the study of animal movement over the past two decades, enabling continuous tracking of individual animals across entire home ranges, migration routes, and dispersal journeys without any need for recapture or observer presence. Modern GPS tags weigh as little as 0.5 grams (small enough to attach to songbirds) and can record locations every 15 minutes for months, transmitting data via satellite when the animal enters range. The Movebank database — which archives GPS tracking data from over 800 species and 5,000 studies — now holds over 3 billion animal locations, enabling analyses of movement patterns, habitat use, and migratory connectivity at scales impossible with conventional radio-telemetry. This data revolution has produced fundamental insights into movement ecology: the discovery that individual animals within a population show dramatically different movement strategies (some residents, some nomads, some intermediate), the quantification of connectivity between distant ecosystems through migratory species, and the identification of critical bottleneck habitats used by many individuals of a species during migration.

Acoustic Monitoring — Listening to Biodiversity

The soundscape of an ecosystem — the combination of biophony (biological sounds), geophony (natural physical sounds), and anthrophony (human-generated sounds) — contains rich information about biodiversity, habitat quality, and ecological function. Passive acoustic monitoring (PAM) — deploying autonomous recording units in the field and using automated algorithms to detect and classify species by their calls — has emerged as a powerful tool for monitoring biodiversity across large areas and extended time periods that would be impractical with traditional observer-based methods. A single acoustic recorder, deployed in tropical forest for a year and processed with machine learning species classifiers, can produce a species inventory for birds, bats, frogs, and insects comparable to weeks of intensive observer effort. The rapidly increasing power of deep learning algorithms for species identification from audio — trained on massive datasets of verified recordings from platforms like xeno-canto (over 700,000 bird recordings from over 10,000 species) — is making acoustic biodiversity monitoring increasingly accessible and globally deployable, with deployment costs falling below $50 per recorder-year for DIY systems.