The Common Swift (Apus apus) is the screaming black silhouette of the Nordic summer sky, a bird so aerial that it spends almost its entire life on the wing. Sooty black overall but for a small white throat patch, it has narrow, scythe-shaped wings and a shallow forked tail that give it a shape unlike any other Swedish bird. Despite superficial resemblance to swallows, swifts are unrelated to them; genetically their closest relatives are hummingbirds and treeswifts, and the similarity is purely the result of convergent evolution.
From the moment a young swift leaves the nest, it does not land again until it returns to breed, sometimes three years later, sleeping, feeding, drinking and even mating entirely in flight. The species nests in crevices under roof tiles and behind bargeboards on churches, towers and older buildings, laying 2-3 eggs incubated for 19-20 days; nest material is caught on the wing and glued together with saliva. Its piercing "srriiiih" scream is heard above all during evening screaming parties, when non-breeding birds chase each other at speed around rooftops before climbing to sleep in the high air. Common Swifts arrive late, in late April or May, once flying insects, their only food, are reliably abundant, and depart again as early as July-August for wintering grounds in sub-Saharan Africa, a round trip of up to 10,000 km. With 200,000-400,000 pairs, the Swedish population is classed as Endangered, declining as renovated buildings seal off the crevices the species depends on.
Read about this species in Swedish →