Swifts

(Apodidae)

Class Aves

Order Apodiformes

Suborder Apodi

Family Apodidae

Thumbnail description
Small to medium-sized, fast flying birds with narrow swept-back wings, square to deeply forked tails, small bills and feet, and sometimes distinctive screaming vocalizations

Size
3.4–9.6 in (9–25 cm); 0.2–7.6 oz (5–205 g)

Number of genera, species
18 genera; 99 species

Habitat
Wide-ranging aerial foragers, but dependent on cliffs, hollow trees, or caves for nesting and roosting sites

Conservation status
Endangered: 1 species; Vulnerable: 5 species; Near Threatened: 5 species; Data deficient: 6 species

Distribution
Nearly worldwide except for coldest and treeless areas of northern hemisphere; most numerous in warmer tropical regions

Evolution and systematics

Swifts are highly specialized, generally fast flying, aerial foragers that rarely come to earth except at nest or roost sites. There have been suggestions of a swift-swallow relationship and an affinity between swifts and hummingbirds. Caprimulgids have also been frequently mentioned as a possibly closely allied group. The view that swifts and hummingbirds are related is influenced by the greatly shortened humerus and elongated distal portion of the wings. More recent DNA evidence has supported this.

The intrafamilial relationships of the swifts have also been debated over the years. Today, consensus supports there being three subfamilies: Cypseloidinae, Chaeturinae, and Apodinae. The Cypseloidinae (two genera; 12 species), with the least derived, or shortened, humerus, are presumed to be the most primitive of the swifts and are today confined to North and South America and the West Indies. Their distinctive habit of nesting and roosting in dark damp areas near or behind waterfalls or in sea caves set them apart from the other swifts.

The Chaeturinae are often called spinetails as many have stiffened shafts with bare tips to the tail feathers and use them for support while perching on vertical surfaces. This subfamily consists of 58 species in 10 genera. It includes the bewildering array of morphologically similar swiftlets or cave swiftlets of Southeast Asia, northern Australia, and many islands in the Indian and Pacific oceans. Determining the species limits among this group has been considered to be among the most daunting in ornithology and has led to most of the variation in the number of species, from 90–99, attributed to the family. Their use of echo-location and the commercial exploitation of their nests further contributes to the uniqueness of the swiftlets.

The Apodinae have a unique lateral grasping foot where toes one and two oppose toes three and four. The Apodinae, the second largest subfamily, consists of 29 species in six genera, including the widespread genus Apus as well as five species of palm-swifts.

Physical characteristics

Swifts are true masters of the aerial environment. With their long narrow swept-back wings, their flight is rapid with frequent changes in direction to capture prey. In some, the rushing noise of their wings or screaming cries announce their presence even before they come into view. Swifts are similar in having narrow-pointed wings with seven to nine secondaries and 10 primaries, the outermost being greatly elongated and more than twice the length of the innermost. They have different tail shapes with many being slightly rounded, square, or shallowly notched, while others are deeply forked. Swifts also differ greatly in size. Body lengths vary from 3.5–9.8 in (9–25 cm) and weights from about 0.17–7.2 oz (5 g–205 g). Among the smallest are the pygmy swiftlet (Collocalia troglodytes) of the Philippines and the pygmy palm-swift (Micropanyptila furcata) in Venezuela. The white-naped swift (Streptoprocne semicollaris) of western Mexico and the purple needletail (Hirundapus celebensis) from the Celebes vie for

honors as the largest, while the widespread and familiar white-collared swift (Streptoprocne zonaris) in the Neotropics and the alpine swift (Apus melba) are intermediate in mass between these extremes.

Generally, swifts are dull-colored creatures with only the chestnut-collared swift (Cypseloides rutilus) and Tepui swift (Cypseloides phelpsi) having a rich chestnut red in addition to the browns, grays, black, and varying amounts of white found in other species. Several swifts have a faint to pronounced greenish irridescent sheen to their freshly molted feathers, but this is largely unobservable except for birds in the hand. In all but a few species, males and females are not separable by external appearance and, in nearly all, there is no appreciable difference in size or mass. The bill of all swifts is small but the gape is large, facilitating capture of aerial prey.

Distribution

Swifts are decidedly more common in the tropical parts of the world where up to eight or nine resident species may occur sympatrically. However, one or more species are also found at high latitudes on all continents other than Antarctica. They are found nesting from sea level to several thousand feet/meters elevation in mountainous regions of Europe, North America, and in the Andes of South America. Three swifts, the common swift (Apus apus), alpine swift (Apus melba), and pallid swift (Apus pallidus), occur as breeding species in Europe and migrate to Africa in the winter. In North America, three species similarly migrate south in winter, two of which, the chimney swift (Chaetura pelagica) and black swift (Cypseloides niger), travel all the way to South America. The white-throated swift similarly migrates from the more northerly portions of its range but is a permanent resident in much of the southwestern United States and Mexico. Two Asiatic breeding swifts, the white-throated needletail (Hirundapus caudacutus) and fork-tailed or Pacific swift (Apus pacificus), make extended migrations to winter in Australia and New Zealand, and occasionally reaching sub-Antarctic Macquarie Island.

Habitat

Swifts occur in a wide variety of habitats from densely forested tropical areas to nearly the limit of suitable nest trees in northern Scandanavia. Others that depend more on rock cliff, or manmade equivalents, for nest sites can utilize extensive nearby open savanna or grassland habitats.

Behavior

Swifts typically leave their nesting and roost sites at dawn and in many cases do not return until dusk. Swifts spend their entire day aloft, only landing at nest sites when feeding young or at nighttime roosts. The daily foraging range of these highly mobile birds has not been adequately studied, but some species may regularly forage in excess of 30–38 mi (50–60 km) from nest or roost sites. Although they may occur singly or in small groups, swifts are highly social birds and flocks of hundreds are often found in suitable feeding areas. During migration, huge flocks of swifts can occur.

Nesting is largely dependent on the nest-type and location; some species such as the lesser swallow-tailed swift (Panyptila cayennensis) build solitary nests under rock clefts or under large limbs of forest trees. Others, notably some of the swiftlets, may nest in dense aggregations where more than 100,000 individuals utilize a single cave system. Swifts conduct much of their courtship and social activities on the wing. The common swift in Europe is noted for its ability to spend nights aloft. These same swifts make extended movements away from breeding areas during spells of cold rainy weather and seek out food by following high-pressure zones; their chicks back in the nest may drop their body temperature and go torpid until both warmer weather and the adults return. Social interactions include a lot of high-speed, usually noisy, aerial chases with intermittent glides and raised-wing displays. In spring, interlocked birds sometimes make dramatic tumbling display falls of nearly 200 ft (60 m) or more which have been interpreted, at least in the white-throated swift (Aeronautes saxatalis), as aerial copulation.

Among the most interesting capacities of the swiftlets in the genus Aerodramus is the ability to echolocate, which means

they emit sharp pulses of sound, or clicks, and utilize the echo of these sounds to enable them to navigate to and from nest or roost sites in the inner regions of caves. These syringeallyproduced sounds are typically brief audible clicks ranging from 2–10 kHz in frequency, with most of the sound energy between 2 and 5 kHz. Repetition rates vary between five and 20 clicks per second. Click rates are lowest in the twilight zone at the cave entrance and increase abruptly when the swiftlets enter the zone of total darkness. The sensitivity of this echolocation system does not allow them to discriminate targets much below 0.19–0.23 in (5–6 mm), which precludes them using it to locate food items.

Vocalizations in swifts are not particularly elaborate or even musical. They range from staccato chatter or chippering in such as the chimney swift to the more drawn out screams of Apus and Aeronautes swifts. Social screaming parties are a familiar sight and sound at dawn and dusk near breeding sites of the common swift in towns throughout much of Europe. The call of the greater swallow-tailed swift (Panyptila sanctihieronymi) in southern Mexico may be an exception in that it has been described as a high clear and descending musical whistle.

Swifts show an extreme long-term fidelity to breeding sites; some are regularly or continuously used for a half century or more. In some cases, nests are used again and again by the same pair of swifts year after year, with only the addition of some new nest material. Others build less durable nests that have to be built anew each season. Swifts are long-lived and generally monogamous. Life-spans may approach 15–20 years or more; annual survival rates can exceed 80%, although they are lower in some of the highly migratory species.

Feeding ecology and diet

Swifts gather all of their arthropod food on the wing, most of which are insects supplemented by the occasional spider.

The specific items taken vary extensively from place to place and even from day to day, particularly in temperate areas where substantial differences in local weather conditions occur. Swifts tend to forage at higher altitudes and take larger food items on bright sunny, warm days when more potential prey are carried aloft in wind currents and thermals. During cooler, overcast or rainy weather, they forage lower and seek out areas of continued insect productivity, such as lakes and settling ponds. Food for the young is generally carried in the mouth and consolidated into a bolus with the addition of a sticky glue-like substance produced by seasonally enlarged salivary glands. A given bolus may contain as many as 1,500 individual insects representing perhaps 50–60 different species. Swifts are quick to exploit local abundances of prey as found in the mating swarms of mayflies, termites, ants, and other insects. The foraging ecology of cypseloidine swifts is substantially different in that they appear to specialize in feeding on the swarms of winged reproductive ants and termites. They also store these prey in the esophagus thus enabling them to forage more widely in search of patchily distributed swarms of these energy-rich prey and then return with a larger load than a single bolus. Their chicks are provisioned only once or twice a day compared to the one to three times per hour for the other swifts. However, they may receive multiple regurgitations on each return of the adults to the nest.

Reproductive biology

Breeding in tropical swifts usually coincides with the onset of the seasonal rains and a flush of insect prey. In swifts in the temperate zone, it begins with the longer and warmer days of late spring and summer, and chick provisioning and

fledging occurs when aerial food supplies are near their peak. This timing is also important to adults that must increase fat reserves prior to their lengthy migrations.

The nests of swifts are highly variable and have proven useful in assessing intrafamilial relationships. The very large needletail swifts (Hirundapus) build no nest at all and lay their eggs in a scrape in the detritus at the bottom of hollow trees, and the white-naped swift utilizes a scrape in the sand on ledges in caves. The Horus swift (Apus horus) usurps burrows of bee-eaters and othe burrowing birds while two other African species, the white-rumped swift (Apus caffer) and Bates's swift (Apus batesi) utilize old swallow nests that they reline with feathers. The most elaborate structures are the tubular nests of the swallow-tailed swifts (Panyptila) of Central and South America, which are made of plant seed floss glued together with salivary cement into a felt-like material. In the chaeturine swifts in the genera Chaetura, Telecanthura, and Neafrapus, and presumably other spinetails, the nest is a neat half-saucer of twigs glued to the inside of a hollow tree. Other swifts build simple or bulky nests of plant material and feathers glued together and located on cliffs, in crevices, or, in the case of the palm swifts, attached to the hanging palm fronds. The cypseloidine swifts are unique in that their nests are a simple pad or cone of mosses or seaweed placed in a damp dark niche near or even behind waterfalls or in sea caves. The swiftlets include varying amounts of plant material and feathers in their nests along with copious amounts of salivary cement. Some such as those of the edible-nest swiftlet (Aerodramus fuciphagus) are made entirely of salivary secretions and are the highly prized ingredient of birds-nest soup and extensively harvested for this delicacy.

Swift eggs are almost uniformly ovate and glossy white in color. Clutch sizes range from only one or two in the cypseloidine swifts and swiftlets to as many as five to seven in some species of Chaetura and Aeronautes. Incubation periods tend to be long, ranging from 19–20 days to about 28 days. Newly hatched chicks are blind, helpless, and devoid of any natal down. A fluffy down-like semi-plume covering starts growing within a few days, which precedes the growth of the first typical contour plumage. Development of the chicks is slow compared to other similar-sized birds and takes from four to six and a half weeks (an extraordinary nine weeks in the spot-fronted swift [Cypseloides cherriei]). In many of the spine-tailed swifts (Chaetura), the young may leave the crowded nest and cling to the walls of the hollow tree nest site for a week or more before actually fledging. Others such as the cypseloidine swifts and cave-inhabiting swiftlets remain in the nest until fledging.

The molt period in swifts is generally prolonged with only a few flight feathers being replaced at the same time. This necessitates extensive overlap of breeding and molt periods in temperate zone species that complete their molt prior to fall migration. Others delay the molt until reaching the wintering ground, or interrupt it shortly after its start to accommodate the energy cost of migration.

Conservation status

Because of their highly specialized nesting requirements, a number of swifts have been included on various lists of threatened or vulnerable species. Destruction or disturbance of localized nesting areas, especially caves, can have an appreciable negative impact on populations of these birds, particularly island populations. A deficiency of detailed information on the breeding biology and status of a number of species of swifts has led to their being tentatively included on lists of those possibly needing protection. One species (Guam swift, Collocalia bartschi) is listed as Endangered by the IUCN. An additional five species are considered Vulnerable and another five species are deemed Near Threatened. Detailed information is badly needed for other poorly studied species.

Significance to humans

Swifts are often found nesting in close association with humans and common swifts used to be encouraged to nest in man-made rooftop compartments where the young could be harvested for food. Even today, swiftlet nests are widely harvested for food and perceived medicinal properties. The feather-free "white" nests of the edible-nest swiftlet (Aerodramus fuciphagus), which are made entirely of the sticky secretions of the salivary glands, are important economic assets throughout their range in the oriental region. So-called "black" nests of the black-nest swiftlet (Aerodramus maximus), which contain substantial amounts of feathers intermixed with the salivary secretions, are also harvested but command a much lower price. Today, the harvest of these nests is closely monitored and regulated. Properly managed, this can be a renewable resource providing a sustained yield year after year. However, illegal harvesting and excessive disturbance threaten the long-term viability of some colonies and the nest-collecting industry. Cross-fostering of young edible-nest swiftlet chicks into nests of other species as a means of establishing new colonies in places where a carefully regulated harvest will be possible is a promising new program.

Species accounts

List of Species

White-collared swift

Streptoprocne zonaris

subfamily

Cypseloidinae

taxonomy

Hirundo zonaris Shaw, 1796, no locality although assumed to be Brazil. Nine subspecies.

other common names

English: Cloud swift, Antillean cloud swift; French: Martinet &agrave collier blanc; German: Halsbandsegler; Spanish: Vencejo Grande.

physical characteristics

8.5 in (22 cm); 3.2–4.0 oz (85.8–107.3 g). Blackish plumage and a distinctive white collar.

distribution

Widespread in Central and South America from northern Mexico south to southern Bolivia and northwestern Argentina; also in Greater Antilles. Extralimital in California, Michigan, Texas, and Florida.

habitat

Occurs over all terrain and habitats from sea level to 13,000 ft (4,000 m) in highlands. More typical in highlands and less common in more arid regions.

behavior

A seemingly very social species often occurring in large flocks of 100–300. Daily foraging flights appear to be lengthy.

feeding ecology and diet

Tends to specialize on swarming insects, particularly winged ants and termites; other insects also taken.

reproductive biology

Nests of mossy material in dense colonies where conditions permit. Two eggs are laid; incubation takes 30–35 days and chicks are fledged after 45–55 days.

conservation status

Inaccessibleness of most nest and roost sites makes them less subject to human activities. No conservation measures identified or proposed.

significance to humans

None known.

Black swift

Cypseloides niger

subfamily

Cypseloidinae

taxonomy

Hirundo nigra Gmelin, 1789, Hispaniola. Three subspecies.

other common names

English: American black swift; French: Martinet sombre; German: Schwarzsegler; Spanish: Vencejo Negro.

physical characteristics

6.9 in (18 cm); 1.5–1.9 oz (41–51 g). Dark plumage usually with white fringe on underparts; females have broader white fringe on underparts.

distribution

Widespread but highly localized breeder in western United States and southern Canada and Alaska, south through Central America to Costa Rica; also breeds in northern West Indies; as yet unidentified wintering ground in South America.

habitat

Forages widely at higher elevations; less common in drier areas away from mountain waterfall and sea cave nesting sites.

behavior

Leaves nest and roost site at first light and only returns at dusk; forages at high altitudes; may nest in larger numbers at a single site.

feeding ecology and diet

Insects and spiders; specializes on swarming insects, particularly winged reproductive ants.

reproductive biology

Nest and the single white egg located in a cool damp dark area adjacent to water; incubation takes 24–27 days and fledging and additional 45–50 days.

conservation status

Nest sites largely free of human disturbances; some traditional breeding sites in coastal California have been unoccupied in recent years; on the list of Species of Special Concern in California, but this is currently under review.

significance to humans

None known.

Chimney swift

Chaetura pelagica

subfamily

Chaeturinae

taxonomy

Hirundo pelagica Linnaeus, 1758, South Carolina, USA. Monotypic

other common names

French: Martinet ramoneur; German: Schornsteinsegler; Spanish: Vencejo de Chimenea.

physical characteristics

4.6–5.4 in (12–14 cm); 0.8–1.0 oz (21.5–28.0 g); average mass of 0.7–1.0 oz (20–23 g) during breeding season, and 0.9–1.0 oz (26–28 g) during pre-migration period. Sooty gray upperparts; dark gray-brown underparts with lighter throat.

distribution

Eastern North America west to Rocky Mountains; occasional breeder in California and southwest in recent years. Migrates through Central America to wintering grounds in Peru and northern Chile. Extralimital in Galapagos, West Indies, Bermuda, and British Isles.

habitat

Widespread occurring over open country, forested areas, and urban centers.

behavior

Makes dashing flights in small groups and rapid chippering vocalizations; nests in chimneys more often than in hollow trees. Helpers at nests of breeding pairs may be young pre-breeders or failed breeders.

feeding ecology and diet

A wide variety of insects taken, including aerial insects and some spiders.

reproductive biology

Nest of twigs glued together and to the wall of the hollow tree or chimney with salivary cement. Clutch is two to seven eggs, more typically four to five, laid between May and mid-July. Incubation takes 19–21 days and chicks fledge after an additional 28–30 days, although they may have vacated the crowded nest as much as a week earlier.

conservation status

Although still common to abundant in most parts of its breeding range, population numbers appear to be declining, probably due to closure or screening of chimney nest sites in urban and suburban areas. Construction of artificial chimney-like structures as alternative nest sites is proving effective.

significance to humans

None known.

Edible-nest swiftlet

Aerodramus fuciphagus

subfamily

Chaeturinae

taxonomy

Hirundo fuciphaga Thunberg, 1812, Java. Eight subspecies.

other common names

English: Gray-rumped swiftlet, white-nest swiftlet, Hume's swiftlet; French: Salangane à nid blanc; German: Weißnestsalangane; Spanish: Salangana Nidoblanco.

physical characteristics

4.6 in (12 cm); 0.4–0.6 oz (10–15 g). Glossy blackish brown upperparts sometimes with lighter rump; underparts are mostly brownish gray with lighter throat and blackish undertailcoverts.

distribution

Southeast Asia and Indonesia, from Andaman and Nicobar Islands through coastal south Thailand, Malaysia, Sumatra, Java, and Borneo to Lesser Sundas.

habitat

Widespread in coastal lowlands but in some places at elevations to 3,280–9,000 ft (1,000 to 2,800 m). Coastal mangroves, cultivated areas, and lowland forest.

behavior

Gregarious and often associates with other swiftlets and swallows when foraging.

feeding ecology and diet

Aerial arthropods, including a wide array of insects and spiders.

reproductive biology

Breeding season is lengthy and peaks in the dryer season of the year. Nests are self-supporting brackets made almost completely of the sticky salivary mucilage. Usually two eggs are laid and incubation period is 25.5 days for the first egg and 22.5 days for the second; the fledging period is 43 days.

conservation status

In areas where unregulated repetitive nest harvesting is taking place, populations as well as harvesting yields are sharply declining by as much as 85% over a 12-year period.

significance to humans

Nest-harvesting provides substantial economic benefits to local human populations.

White-rumped swiftlet

Aerodramus spodiopygius

subfamily

Chaeturinae

taxonomy

Macropteryx spodiopygius Peale, 1848, Samoa Islands. Eleven subspecies.

other common names

Gray swiftlet, Pacific white-rumped swiftlet; French: Salangane à croupion blanc; German: Weißbürzelsalangane; Spanish: Salangana Culiblanca.

physical characteristics

3.3–4.4 in (10–11.5 cm); 0.3 oz (8.2 g). A highly polytypic species. All have a pale rump, but the degree of paleness varies geographically.

distribution

Extensive range on oceanic islands in Papuasia, Melanesia, and Polynesia from island groups off New Guinea eastward to New Caledonia, Fiji, Tonga, and Samoa; New Zealand.

habitat

Island-inhabiting species occurring widely. Generally found in lowlands but sometimes to 5,250–5,900 ft (1,600–1,800 m) on larger islands.

behavior

Feeds in association with other swiftlets and swallows: utilizes echolocation to access nest sites.

feeding ecology and diet

Wide array of insects, including aerial insects and spiders.

reproductive biology

Nest is of fine plant material and mosses held together with salivary cement and attached to the wall of a cave. Clutch size is one or two eggs. Incubation period is 22–25 days; fledging period is 45–46 days. Lost eggs and sometimes lost broods are usually replaced in 9–14 days.

conservation status

A high fledging success rate suggests stable populations.

significance to humans

None known.

White-throated needletail

Hirundapus caudacutus

subfamily

Chaeturinae

taxonomy

Hirundo caudacuta Latham, 1801, New South Wales, Australia. Two subspecies.

other common names

English: Spine-tailed swift, needle-tailed swift, northern or Asiatic needletail; French: Martinet épineaux; German: Stachelschwanzsegler; Spanish: Vencejo Mongol.

physical characteristics

7.3–7.6 in (19–20 cm); 4.0–5.2 oz (109–140 g). Brown body with off-white mantle and white throat, forehead, and markings on flanks and undertail-coverts; dark wings with blue gloss fading to green on remiges and coverts. Juveniles have black terminal tips to some of the undertail-coverts.

distribution

Forested areas from central Siberia east to Sachalin, Kurile Islands, and northern Japan; southern Himalayas; wintering in Australia and New Zealand, and to sub-Antarctic Macquarie Island. Accidental in Seychelles, western Europe, and British Isles. Only North American records in Pribiloff Islands.

habitat

Dense old-growth forest with abundance of dead and hollow trees; occasionally roosts in large eucalyptus groves.

behavior

Often occurs in large flocks; sometimes forages close to trees, even striking the vegetation to flush out insect prey. Considered to be one of the fastest flying birds, reaching speeds in excess of 100 mi/hr (170 km/hr).

feeding ecology and diet

A wide diversity of insects and spiders.

reproductive biology

Uses hollow interior of large forest trees as nest sites. Clutch ranges from two to seven eggs, which are incubated starting with the first egg causing hatching to be asynchronous. Breeding in late May through the middle of June; migration begins in late September and early October.

conservation status

Species is not in need of any conservation measures.

significance to humans

None known.

Common swift

Apus apus

subfamily

Apodinae

taxonomy

Hirundo apus Linnaeus, 1758, Sweden. Two subspecies.

other common names

English: Eurasian, European, northern swift; French: Martinet noir; German: Mauersegler; Spanish: Vencejo Común.

physical characteristics

6.1–6.5 in (16–17 cm); 1.3–1.9 oz (36–52 g). Juvenile similar to adult; sexes alike. Overall black-brown plumage with small, off-white throat patch.

distribution

Western Europe to eastern Asia and from northern Scan-danavia and northern Siberia to North Africa, Himalayas, and central China; winter in southern Africa. Accidental in Spitzbergen, Iceland, Bermuda, and Seychelles.

habitat

Occurs in all but driest parts of extensive breeding range. Nests in woodpecker holes, hollow trees, and natural cliffs as well as buildings and other manmade structures.

behavior

Regularly makes dashing flights accompanied by its drawn-out rattling screams. During prolonged cold weather, adults may temporarily abandon the chicks and make lengthy flights to warmer, food-rich areas. Annual molt is usually delayed until they are on the wintering grounds.

feeding ecology and diet

Aerial insects and spiders taken on the wing.

reproductive biology

Lay from one to four eggs, most commonly two, and incubation takes about 19–20 days; fledging takes an additional 27–45 days. Nesting success varies from 58% to 65%.

conservation status

Most populations seem to be healthy and not in need of particular conservation efforts.

significance to humans

None known.

Alpine swift

Apus melba

subfamily

Apodinae

taxonomy

Hirundo melba Linnaeus, 1758, Gibraltar. Ten subspecies.

other common names

French: Martinet à ventre blanc; German: Alpensegler; Spanish: Vencejo Real.

physical characteristics

7.8–8.5 in (20–22 cm); 2.8–4.5 oz (76–120 g); largest swift of Europe and throughout most of its range. Olive-brown upperparts; underparts have a large white oval patch encircled by olive-brown breast band, flanks, and undertail-coverts; white throat.

distribution

Widely distributed in mountainous areas and along coastal cliffs from Pyrenees and Alps of western Europe eastward to the Himalayas and peninsular India; mountainous areas of east and southern Africa, Madagascar, and Arabian peninsula; winters in central and western Africa. Accidental in Scandinavia, British Isles, Iceland, and Caribbean.

habitat

Occurs widely at higher elevations; forests, cultivated areas, and highly urbanized sites.

behavior

Screaming parties around breeding areas are common. Mating takes place on the wing as well as in nest chamber.

feeding ecology and diet

Wide array of aerial insects and spiders.

reproductive biology

Nests are small pads of plant material and feathers in a cliff or natural cavity. Normally three eggs are laid, but sometimes as few as one or as many as four. Incubation period is 17–23 days: fledging at an age of 53–66 days.

conservation status

Conservation efforts have increased populations in some areas.

significance to humans

None known.

African palm swift

Cypsiurus parvus

subfamily

Apodinae

taxonomy

Cypselus parvus Lichtenstein, 1823, Nubia. Eight subspecies.

other common names

English: Palm swift, Old World palm swift; French: Martinet des Palmes; German: Palmensegler; Spanish: Vencejo Palmero Africano.

physical characteristics

6.1 in (16 cm); 0.4–0.5 oz (10–14 g). One of the smallest African swifts. Pale gray-brown upperparts with head and wings appearing darker; underparts very pale with some streaking on the throat. Males have whiter throats than females.

distribution

Widespread in sub-Saharan Africa, including Madagascar.

habitat

Local foraging species in open areas in the vicinity of palms; generally forages at low to medium heights.

behavior

Close association with palms which provide year-round roosting and nesting sites. Vocalizations a soft high-pitched scream.

feeding ecology and diet

Aerial arthropods, including diverse small insects and spiders, as well as winged ants, termites, and beetles.

reproductive biology

Nests are small elongate pads of plant floss and feathers glued to the surface of hanging palm fronds. Clutch sizes are usually one or two eggs, rarely three. Incubation is typically 20 days. Chicks grow slowly and fledge after a period of 31–33 days.

conservation status

Plantings of both native and exotic palms in suburban areas has resulted in a stable population.

significance to humans

None known.

Resources

Books

Arn-Willi, H. Biologische Studien am Alpensegler. Solothurn: Verlag Vogt-Schild.1960.

Chantler, P. Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition. New Haven: Yale University Press, 2000.

del Hoyo, J., A. Elliot, and J. Sargatul, eds. Handbook of the Birds of the World. Vol 5. Barn Owls to Hummingbirds, Barcelona: Lynx Editions, 1999.

Francis, C. M. The Management of Edible Bird's Nest Caves in Sabah. Sandikan: Wildlife Section, Sabah Forest Department, 1987.

Lack, D. Swifts in a Tower. London: Methuen and Co. Ltd., 1956.

Sibley, C. G., and J. E. Ahlquist. Phylogeny and Classification of Birds: A Study in Molecular Evolution. New Haven: Yale University Press, 1990.

Periodicals

Collins, C. T. "The Comparative Biology of Two Species of Swifts in Trinidad, West Indies." Bulletin of the Florida State Museum 11 (1968): 257–320.

Collins, C. T. "Subfamilies of the Swifts (Apodiformes: Apodidae): Schoutedenapus Revisited." Durban Museum Novitates 25 (2000): 36–39.

Collins, C. T., and R. K. Brooke. "A Review of the Genus Hirundapus (Aves: Apodidae)." Natural History Museum of Los Angeles County, Contributions in Science 282 (1976): 1–22.

Lack, D., and E. Lack. "The Breeding Biology of the Swift." Ibis 93 (1951): 501–546.

Marin A. M., and F. G. Stiles. "On the Biology of Five Species of Swifts (Apodidae, Cypseloidinae) in Costa Rica." Proceedings of the Western Foundation of Vertebrate Zoology 4 (1992): 287–351.

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