The bird is superficially similar to a large Barn Swallow or House Martin. It is, however, completely unrelated to those passerine species, since swifts are in the order Apodiformes. The resemblances between the groups are due to convergent evolution, reflecting similar life styles.
Swifts have very short legs which they use only for clinging to vertical surfaces. The scientific name comes from the Ancient Greek απους, apous, meaning "without feet". They never settle voluntarily on the ground.
Alpine Swifts breed in mountains from southern Europe to the Himalaya. Like Common Swifts, they are strongly migratory, and winter much further south in southern Africa. They wander widely on migration, and are regularly seen in much of southern Europe and Asia. The species seems to have been much more widespread during the last ice age, with a large colony breeding for example at Komarowa Cave near Częstochowa, Poland, around 40,000-20,000 years ago (Tomek & Bocheński 2005). Dubrovnik is notable for the large flocks of alpine swifts which nest in the old city walls. The species typically builds its nest on cliff faces, but will also nest in urban areas, choosing places that are inaccessible to predators, such as roof spaces and underneath bridges
Alpine Swifts build their nests in colonies in a suitable cliff hole or cave, laying 2-3 eggs. A swift will return to the same site year after year, rebuilding its nest when necessary. These birds pair for life.
Young swifts in the nest can drop their body temperature and become torpid if bad weather prevents their parents from catching insects nearby.
Alpine Swifts spend most of their lives in the air, living on the insects they catch in their beaks. They drink on the wing, but roost on vertical cliffs or walls.
Alpine Swifts are readily distinguished from the Common Swifts by their larger size and their white belly and throat. The Alpine Swift is around twice as big as most other swifts in its range. It is 20 to 23 cm (7.9 to 9.1 in) long, with a 57 cm (22 in) and weighed around 100 g (3.5 oz). The Alpine swift is largely dark brown in colour, with white patches underneath the beak and on the breast that are separated by a dark brown streak. The juvenile is similar to the adult, but the feathers are pale edged.In comparison, the Common Swift has a wingspan of around 42 cm (17 in). A dark neck band separates the white throat from the white belly. They have a short forked tail and very long swept-back wings that resemble a crescent or a boomerang but may (as in the image) be held stretched straight out. The flight is slower and more powerful than that of their smaller relative.
The call is a drawn-out twittering.
Taxonomy
In the Sibley-Ahlquist taxonomy, the old order Apodiformes is split. Swifts remain in that order, but hummingbirds are put into a new order, Trochiliformes. This is not generally accepted due to being contradicted by fossil evidence .
Order Swifts/Apodiformes, Family Swifts/Apodidae
Alpine Swift/Tachymarptis melba - Adult
Photographer: ©
Светослав Спасов
- http://www.NatureImages.eu
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