In the spotlight Swift (Apus apus)

Welcome back to the swifts, the anchor-shaped, vocal acrobats of the skies so emblematic of summer. Few creatures are as remarkable as the diminutive Apus apus, with its long and arduous migration journey. Arriving in May, the sojourn is brief—just long enough, if conditions are favourable, to raise a brood—before they speed back to central and southern Africa, often as early as July. Feeding on flying insects, they also gather whatever meagre rations of nesting material they can find when swooping through the skies, cementing it with their own saliva, for swifts never land except when raising a family. How is sleep achieved? Apparently, by alternately shutting down half of the brain and ‘resting’ at high altitude. A young swift spends its first two or three years in constant flight. Dark brown all over, but pale at the chin and with a characteristic forked tail, the swift’s airborne lifestyle has left its legs underdeveloped, but strong claws enable it to grip and shuffle into nesting holes and crevices in cliffs and the roofs of high buildings.