Migratory bat species undertake long-distance seasonal movements between summer and winter roosts, facing hazards from wind turbines, light pollution, and habitat loss along migration routes that kill millions annually.
Migratory bat welfare is dominated by the wind energy mortality problem — one of the clearest examples of a renewable energy technology creating significant wildlife welfare harms that can be substantially reduced through operational changes. Barotrauma causes internal haemorrhage that may be rapidly or slowly fatal, with welfare implications for the duration of the dying process. The technological fix — curtailment during low wind speed, high bat activity periods — is known, proven, and modestly costly in energy generation terms. Scaling adoption of curtailment protocols through regulation rather than voluntary compliance is the most direct welfare intervention available. Habitat protection along migration routes addresses the secondary challenge of maintaining food and roosting resources.