Broadly Applicable Tracking System (BATS): a lightweight wildlife tracking tag

Design and operation

BATS devices are compact assemblies that combine positioning, short-range wireless communication and on-board data storage in a package that prioritizes low weight and low power consumption. The outer shell or housing is often produced by 3D printing to achieve a tailored form factor. Attachment methods are chosen to balance secure placement with animal welfare; on small bats the unit is glued to fur in a way that typically allows it to detach after a limited period. Developers emphasize that a lightweight design reduces the risk of altering natural behaviour during flight.

• Positioning: GPS or other location sensors record spatial movements when available.
• Wireless links: Short-range radio or Wi‑Fi connections transmit logged data when the animal comes near a receiver or network.
• Data logging: On-board memory preserves observations while animals are out of range.
• Reusability: Many components are recoverable and reusable after the tag detaches.

History and development

BATS emerged from efforts to extend fine-scale tracking to very small species that cannot carry conventional telemetry or GPS collars. By focusing on miniaturization, modular fabrication and energy efficiency, research teams produced a tag that can be produced at lower cost and adapted for different study species and field situations. The approach builds on decades of telemetry work but addresses specific challenges of small, volant or crevice-dwelling animals.

Uses, examples and scientific value

Researchers use BATS to document movement patterns, roosting sites, foraging trips and social contacts among individuals. One application combined BATS tracking with behavioral observation to show that captive social relationships formed by vampire bats were retained after the animals were released and resumed normal interaction patterns in the wild; this result helped illuminate social memory and bonding in a wild mammal (vampire bats are a commonly studied example).

Beyond bats, broadly applicable miniaturized tags are useful for small birds, arboreal mammals and other species with complex three‑dimensional movement or that use enclosed roosts such as tree cavities and caves. The ability to log data while animals are inside structures — and then offload records when they return to range — makes these systems especially valuable for studying animals in concealed habitats.

Limitations, welfare and best practices

Although BATS-style tags reduce mass and power demands compared with larger telemetry packages, they still require careful ethical review and field testing. Best practices include selecting attachment methods that minimize stress, following accepted limits on tag mass relative to body mass, monitoring captive individuals before release, and designing studies so that tag loss and component recovery are feasible. Technical constraints such as limited battery life, the need to retrieve some data physically, and reduced accuracy inside dense canopy or underground environments remain practical considerations.

• Plan recoverable deployments and consider seasonal effects on adhesion and behaviour.
• Report tag mass and attachment methods so results are comparable across studies.
• Combine tracking data with behavioral observation and social network analysis for richer interpretation.

When applied responsibly, broadly applicable tracking systems expand the range of species and behaviours that can be studied in the wild, offering new insights into movement ecology, social systems and habitat use for small, mobile animals.