Acoustic monitoring of bats using ultrasonic detectors has transformed conservation research, but some monitoring and tagging methods carry welfare risks that best-practice protocols aim to minimise.
Non-invasive acoustic monitoring represents a huge advance for bat research, allowing population assessments and activity mapping without the welfare costs of trapping and handling. However, some research questions still require physical marking, including radio-tracking, PIT tags, or wing bands. For these methods, welfare protocols specify minimum handling times, appropriate harness sizing, and restrictions on when in the annual cycle marking is permissible. Roost surveys and hibernation checks must be conducted with minimum disturbance. The emergence of autonomous acoustic monitoring units and sophisticated bioacoustic analysis software is reducing the need for invasive techniques, and welfare standards in bat research have improved markedly alongside technological advances.