The common swift (Apus apus) is one of the most aerial of all birds, spending almost its entire life in flight. Swifts breed in cavities in buildings and cliff faces, returning each year to the same sites. Understanding swift welfare requires appreciating both their extraordinary life history and the specific threats they face from modern building practices and habitat change.
Swift Life History and Natural Welfare
Swifts are among the most committed aerial insectivores, capturing all food and water in flight, mating in flight, and sleeping on the wing during non-breeding periods. A swift that cannot fly faces almost certain death, as they are unable to take off from flat ground. Their welfare is therefore entirely contingent on the ability to fly and access aerial insect prey.
Swift populations feed on aerial plankton — the community of small flying insects that populate the air above their breeding territories. Reductions in insect abundance from pesticide use, habitat change, and pollution directly reduce swift welfare by reducing food availability. Breeding swifts with chicks to feed are particularly vulnerable to food shortages, which cause chick starvation and adult condition loss.
Breeding Colony Welfare
Swifts breed in tight-packed colonies, often in the cavities of older buildings. Modern building renovation and demolition frequently destroys swift nest sites. Loss of breeding sites prevents swift reproduction and forces pairs to search for alternative sites, with energetic costs and reduced breeding success. Building regulations in some jurisdictions now require surveys for swift colonies before renovation and mitigation through provision of swift bricks or boxes.
Swift bricks — purpose-built nest cavities integrated into building walls — provide replacement nest sites that swifts readily adopt. Installation of swift bricks in new buildings and during renovation creates habitat that benefits swift populations for decades with minimal ongoing cost.
Individual Welfare Concerns
Grounded swifts — birds unable to take off — present welfare emergencies. Young swifts leaving the nest occasionally land on the ground before they can fly effectively. Licensed swift workers and general public volunteers retrieve grounded birds, assess their condition, and where appropriate release them from a height to allow flight to resume. Training programs for swift rehabilitation volunteers are provided by organizations including the RSPB and Swift Conservation.
Monitoring and Conservation Action
Swift population monitoring through nest site surveys and audio monitoring of swift call sites provides data for conservation planning. Swift-calling playback at suitable nest sites can attract breeding birds to establish new colonies. Community science programs engaging local volunteers in swift monitoring generate population data while building constituency for swift conservation.