Tachymarptis melba (Linnaeus, 1758)

Taxonomic Classification

Tachymarptis melba, the alpine swift, is a large swift species in the order Apodiformes.

Basic Size and Morphology

It measures 20–22 cm in length with a 54–60 cm wingspan, has broad wings and a shallow forked tail.

Convergent Evolution Resemblance

It is superficially similar to unrelated large barn swallows or house martins, a resemblance likely resulting from convergent evolution that reflects their similar lifestyles.

Upperpart Plumage

Its upperparts are olive-brown, with long, sharp wings that have blacker wingtips.

Underpart Plumage

Its underparts have a white throat that is often not easily visible, and a highly visible, distinctive oval white belly patch surrounded by an olive-brown breastband, flanks, and undertail-coverts.

Subspecies Plumage and Size Variation

Multiple recognized subspecies differ in size and plumage: the subspecies tuneti and marjoriae are paler, with grey-brown plumage; archeri is typically paler than tuneti and has shorter wings; maximus is the largest subspecies, with very dark, blackish plumage; africanus and nubifugus are smaller than the nominate subspecies, with blacker plumage, a smaller throat patch, and blacker shaft-streaks on white areas; willsi and bakeri are both smaller, with darker plumage and have broader and narrower breast bands respectively; dorabtatai has a broader breast band and shorter wings than nubifugus, and is distinguished from bakeri by its paler plumage and broader breast band.

Average Species Measurements

By average measurements, alpine swifts are around twice the size of most other swifts in their range: they measure 20 to 23 cm in length, have a wingspan of around 57 cm, and weigh around 100 g.

Common Swift Size Comparison

For comparison, the common swift has a wingspan of around 42 cm.

Wing Structure

Alpine swifts have very long swept-back wings that resemble a crescent or a boomerang, and may be held completely straight out.

Flight and Call Characteristics

Their flight is slower and more powerful than that of smaller related swifts, and their call is a drawn-out twittering.

Distinction from Common Swifts

They are easily distinguished from common swifts by their larger size, white belly, and white throat; they are largely dark brown, with a dark neck band that separates the white throat from the white belly.

Juvenile Plumage

Juveniles resemble adults, but have pale-edged feathers.

Breeding Range

Alpine swifts breed in mountain regions from southern Europe to the Himalaya.

Migratory and Wintering Range

Like common swifts, they are strongly migratory, and winter much further south in southern Africa.

Migration Wandering Pattern

They wander widely during migration, and are regularly seen across much of southern Europe, the Middle East, and Asia.

Pleistocene Fossil Distribution

Fossil evidence shows the species was much more widespread during the last ice age: large breeding colonies existed in what is now Bulgaria's Late Pleistocene Cave No 16 around 18,000–40,000 years ago, and in Komarowa Cave near Częstochowa, Poland around 20,000–40,000 years ago.

Nesting and Clutch Details

This species builds nests in colonies in cliff holes or caves, and lays two or three eggs per clutch.

Breeding Site Fidelity

Swifts return to the same breeding sites each year, rebuild nests as needed, and pair for life.

Chick Cold Weather Adaptation

If bad weather prevents parent birds from catching insects nearby, young swifts in the nest can drop their body temperature and enter torpor.

Urban Adaptation

They have adapted well to urban environments, and frequently nest in old buildings in Mediterranean towns, where large low-flying flocks are a common summer sight.

Subspecies Count

Tachymarptis melba is a polytypic species with 10 recognized subspecies.

Year-Round Range

It is present year-round in eastern and southern Africa, Madagascar, western peninsular India, and Sri Lanka.

Non-Breeding Range

It has a larger non-breeding range covering western, eastern, and southern Africa, and parts of the western edge of the Arabian peninsula.

Breeding Range Extent

It breeds across southern Europe from the west through Turkey, north through the Caucasus, along the east coast of the Black Sea to the Crimean peninsula, through Central Asia to Turkestan, and south through Iran and Afghanistan to Balochistan in Western Pakistan, and further east along the Himalayas.

Scattered African Breeding Populations

There are also scattered populations in northwestern Africa, including an isolated population in Northern Libya.

Vagrant Records

Vagrant individuals have been recorded in parts of the Americas, including Bermuda, Brazil, Barbados, Puerto Rico, French Guiana, Saint Lucia, and Guadeloupe.

Nominate Subspecies Details

The 10 recognized subspecies are: (1) T. m. melba, described by Linnaeus (1758) with type locality Gibraltar, weighing 76–120g, distributed across southern Europe east from the Iberian Peninsula and northern Morocco, east through Asia Minor to northwest Iran, and wintering in west, central, and east Africa;

T. m. tuneti Subspecies Details

(2) T. m. tuneti, described by von Tschusi in 1904 with type locality Tunisia, weighing 95–110g, distributed from central and eastern Morocco eastwards to Libya, through the Middle East and Iran (excluding the northwest where T. m. melba occurs) to southeast Kazakhstan and western Pakistan, and wintering in west and east Africa;

T. m. archeri Subspecies Details

(3) T. m. archeri, described by Hartert (1928) with type locality Hargeisa, Somaliland, distributed from the Dead Sea depression on the borders of Israel and Jordan, south to southwest Arabia and Somalia;

T. m. africanus Subspecies Details

(4) T. m. africanus, described by Temminck (1815) with type locality South Africa, weighing 67–87g, distributed across east and southern Africa and southwest Angola, with some populations wintering in east Africa;

T. m. maximus Subspecies Details

(5) T. m. maximus, described by Ogilvie-Grant (1907) with type locality on the eastern slopes of the Rwenzori mountains at 3,000–3,700 m, averaging 128g, distributed across Uganda and DR Congo;

T. m. marjoriae Subspecies Details

(6) T. m. marjoriae, described by R D Bradfield (1935) from Quickborn, Damaraland, distributed in Namibia and adjacent northwestern Northern Cape, western South Africa;

T. m. willsi Subspecies Details

(7) T. m. willsi, described by Ernst Hartert (1896) from Madagascar, and is endemic to the island;

T. m. nubifugus Subspecies Details

(8) T. m. nubifugus, described by Koelz (1854), distributed across the Himalayas and wintering in central India;

T. m. dorabtatai Subspecies Details

(9) T. m. dorabtatai, described by Abdulali (1965), distributed in western peninsular India;

T. m. bakeri Subspecies Details

(10) T. m. bakeri, described by Hartert (1928) from Sri Lanka, distributed only on that island.

Western Palearctic Habitat

In the western Palearctic's temperate and Mediterranean zones, alpine swifts typically occupy mountains, and occasionally occur in lowlands.

Sub-Saharan and South Asian Habitat

In the rest of sub-Saharan Africa and south Asia, they occur in a wider range of habitats, from sub-desert steppe to mountains.

Typical Breeding Elevation

They typically breed below 1,500 m, and may occasionally breed up to 2,300 m.

Tropical Breeding Elevation Records

In the tropical Kenyan part of their range, they have been recorded breeding above 4000 m; in the Himalayas, they have been observed foraging at 3,700 m; probable nesting sites at 2,100 m have been recorded on Madagascar.

Flight Pattern

Alpine swifts have a powerful, rapid flight with deep, slow wing beats.

Twilight Ascent Behavior

They engage in twilight ascent: increased flight activity, gaining altitude, and longer-distance horizontal flight at dawn and dusk, which may be part of social interactions between individuals.

Aerial Feeding Behavior

Alpine swifts spend most of their lives in the air, feeding on insects caught in their beaks.

Aerial Drinking and Roosting

They drink while flying, and roost on vertical cliffs or walls.

Extended Flight Capability

A 2013 study confirmed alpine swifts can spend over six months flying without landing, and all vital physiological processes including sleep can occur while airborne.

Continuous Flight Research

In 2011, Felix Liechti and colleagues at the Swiss Ornithological Institute attached electronic movement-logging tags to six alpine swifts, and discovered the birds could stay aloft continuously for more than 200 days.

Diet Composition

The alpine swift's diet consists mainly of arthropods, primarily insects, and also includes spiders.

Recorded Diet Taxa

Insects from 10 orders and 79 families have been recorded in the diets of individuals from Africa and Europe, with Homoptera, Diptera, and Hymenoptera being the most commonly consumed groups.