The Common Swift is the creature most closely associated with the claim of “never landing.” Its biology is a tribute to life in the air, allowing it to perform all essential life functions without touching the ground for months at a time.
Identifying the Aerial Master
The Common Swift, scientifically named Apus apus, is a medium-sized migrant that travels vast distances. It spends its non-breeding season in continuous, uninterrupted flight. Tracking studies confirmed that some individuals remain airborne for up to 10 consecutive months while migrating between Europe and sub-Saharan Africa.
The swift “never lands” is a slight exaggeration, but rooted in fact. A mature swift only makes contact with a surface when nesting or caring for young in a cavity. During migration, birds that made stops still spent over 99% of their time in flight. A young swift, once fledged, may not land again for nearly two full years until it is ready to breed.
Specialized Anatomy for Airborne Existence
The swift’s endurance is powered by a morphology tuned for efficiency and speed. Its wings are long, narrow, and distinctly scythe-shaped, optimized for high-speed flight and efficient gliding. This design allows the bird to maximize air currents and minimize energy expenditure.
A large section of the wing is comprised of the “hand” bones, giving the swift exceptional maneuverability. This allows the bird to change its wing geometry mid-flight and maintain speed and control across aerial conditions. The scientific name Apus is derived from the Ancient Greek meaning “without foot.”
The swift possesses very short, vestigial legs that are poorly developed for walking or taking off from flat ground. These feet are only suitable for clinging vertically to rough surfaces, such as a cliff face or a chimney. If a swift accidentally lands on the ground, it struggles to become airborne again, making it vulnerable to predators.
The Logistics of Life in Flight
The swift has evolved specialized behaviors to manage survival while remaining in the air. Its diet consists of “aerial plankton,” tiny insects and spiders it catches with its wide, gaping mouth while flying. These insect swarms are typically hunted at moderate speeds.
Hydration is managed by skimming over the surface of water, such as a river or pond, to scoop up liquid without breaking flight. Reproduction is also an aerial affair, as swifts are often observed mating high above the ground. Remaining airborne provides a distinct advantage, protecting the birds from many ground-based predators and parasites.
Rest and sleep are managed through controlled gliding at high altitudes. Researchers suggest they utilize unihemispheric slow-wave sleep, similar to that observed in marine mammals. This allows one half of the brain to rest while the other remains alert. Rest is often taken during daily ascents at dawn and dusk, where the bird may climb over 10,000 feet before beginning a slow, spiraling glide. During these periods, swifts can slow their movement to a gliding speed of approximately 20 kilometers per hour.