Introduction
The White-naped Swift, Streptoprocne semicollaris, is a large, dark-plumaged swift of mountainous Mexico. It belongs to the swift family Apodidae and is best known for the sharply contrasting white crescent on the back of its neck. The species is usually encountered in fast-flying flocks over highland forests, cliffs, deep ravines and other rugged terrain.
Physical Description
The White-naped Swift is a large swift, measuring approximately 20.5–22 centimetres in length, with a wingspan that may approach 48 centimetres. Adults are mainly brownish-black to black, often with a subtle blue gloss on the upperparts. The diagnostic feature is a white crescent or partial collar across the nape. The white does not form a complete collar around the throat and breast.
The tail is relatively broad and appears nearly square, although its shape can look slightly notched in flight. The sexes are similar in plumage. Young birds are less glossy and may show paler edging to the feathers, but age-related field differences are not well documented.
Range and Habitat
The White-naped Swift is largely resident in western and central Mexico, with its principal range extending through mountainous areas from the Sierra Madre Occidental towards the central highlands and the Sierra Madre Oriental. A small number of records have also been reported near the Guatemala border.
It is associated with highland landscapes containing cliffs, deep river gorges, caves and high crags. Foraging areas include pine-oak forest, tropical deciduous forest, woodland edges and second-growth scrub. It is most often recorded at roughly 1,500–3,000 metres above sea level, although it can occasionally occur lower.
The species is not regarded as a long-distance migrant. Local movements may occur as birds travel between nesting or roosting sites and nearby feeding areas.
Where to See This Species
Iztaccíhuatl–Popocatépetl National Park, México, Puebla and Morelos, Mexico
The White-naped Swift is documented in this high-elevation protected area, which includes extensive volcanic landscapes, pine and fir forests, open slopes and rugged terrain. Watch over forest edges, valleys and craggy slopes, particularly when groups of swifts are moving through the area.
Nearby accommodation: Amecameca and other gateway settlements around the park provide hotels, guest houses, cabins and campsites.
El Tepozteco National Park, Morelos, Mexico
The park’s management information lists the White-naped Swift among its birds. Its steep mountain scenery, cliffs, forest and surrounding valleys offer suitable habitat, and the species may be seen passing overhead rather than perched in the open.
Nearby accommodation: Tepoztlán is the main gateway, with hotels, guest houses, small inns and self-catering accommodation.
Monarch Butterfly Biosphere Reserve, Michoacán and México, Mexico
The White-naped Swift is recorded in the reserve’s bird list. The reserve’s highland pine and fir forests, open clearings and rugged slopes are suitable for scanning the sky for fast-moving flocks, especially during periods of local activity in the highlands.
Nearby accommodation: Angangueo, Ocampo and nearby reserve communities offer guest houses, small hotels, cabins and campsites.
Behaviour and Diet
The White-naped Swift is strongly aerial and spends much of the day on the wing. It has a powerful, direct flight, but can also circle on rising air currents over ridges and valleys. It feeds by capturing flying insects in the air, including beetles, bees, flying ants and other small insects.
It is a social species and may form flocks ranging from small groups to several hundred birds. Flocks may travel considerable distances from nesting or roosting sites to feeding areas and can sometimes gather with other swift species.
Breeding colonies are associated with caves, cliffs and sheltered rock faces. The nest is generally a shallow depression made in dry sand or another suitable surface on a ledge. Two white eggs are typically laid. Details of incubation and parental care remain less well documented than in many more intensively studied birds, but both adults are believed to contribute to raising the young.
Identification Tips
- Look for a very large, broad-winged swift with a fast, powerful flight.
- The plumage is predominantly dark brownish-black or black, sometimes with a blue gloss.
- The white marking is restricted mainly to the nape and forms a partial crescent rather than a complete collar.
- The tail usually looks broad and nearly square, not deeply forked.
- Large, noisy flocks over mountain valleys, cliffs or forested ridges are worth checking carefully.
- The White-collared Swift, Streptoprocne zonaris, is a particularly important comparison. It usually shows a more complete white collar extending around the sides of the neck and onto the breast, whereas the White-naped Swift has a white nape but dark underparts.
Conservation Status
The White-naped Swift is currently assessed as Least Concern on the IUCN Red List. It has a geographically restricted range, but the global assessment does not identify it as facing an immediate high risk of extinction.
Localised threats may include disturbance at caves and cliffs, loss or degradation of highland forest, and changes to the surrounding landscapes used for foraging. Protecting known nesting and roosting sites, retaining native forest and limiting disturbance around colonies are sensible conservation measures. Reliable global population figures and a detailed population trend are not available, so they should not be inferred from local sightings.
Frequently Asked Questions
Where is the White-naped Swift found?
It is found mainly in mountainous western and central Mexico, with records extending from the Sierra Madre Occidental into the central highlands and Sierra Madre Oriental. A small number of records have also been reported near the Guatemala border.
What does the White-naped Swift look like?
It is a large, dark swift with long pointed wings, a broad nearly square tail and a distinctive white crescent on the back of the neck. The white marking does not form a complete collar around the throat.
What does the White-naped Swift eat?
It feeds on flying insects captured during flight. Reported prey includes beetles, bees, flying ants and other small aerial insects.
Does the White-naped Swift migrate?
It is generally regarded as resident rather than a long-distance migrant. Local movements between breeding, roosting and feeding areas may occur.
Where does the White-naped Swift nest?
It nests in caves, cliff faces and other sheltered rocky sites. The nest is usually a shallow depression on a ledge, often formed in dry sand or a similar substrate.
How can it be distinguished from the White-collared Swift?
The White-naped Swift has a white crescent mainly across the nape and dark underparts. The White-collared Swift generally has a more complete white collar that extends around the neck and onto the breast, and its tail is more strongly notched.
References
- BirdLife International
- Cornell Lab of Ornithology, Birds of the World
- Comisión Nacional de Áreas Naturales Protegidas (CONANP)
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