Overview
Vaux's Swift: Small swift, gray-brown body, sometimes highlighted by slight green iridescence. Rump is pale brown, throat and breast are nearly white. Bill, legs, feet are gray-black. Flight is low and fast, alternates bursts of quick fluttery wing beats with short glides. Catches insects in flight.
Range and Habitat
Vaux's Swift: Breeds from southeastern Alaska and Montana to central California. Spends winters in the tropics. Preferred habitats include old growth coniferous or deciduous forests consisting of coniferous and deciduous vegetation; requires large, hollow trees for nesting.
Swifts (Apodidae)
ORDER
The taxonomic order APODIFORMES (pronounced a-poh-dih-FOR-meez) is made up of four families of birds that occur on all continents except for Antarctica and includes the glittering hummingbirds, the strange owlet-nightjars, and the swifts.
FAMILY TAXONOMY
The Apodidae (pronounced a-POH-dih-dee) family is composed of one hundred and one species of swifts in nineteen genera found nearly throughout the world.
NORTH AMERICA
Twenty-five species of the Apodidae in nine genera have occurred in North America. Among these are included the Chimney Swift, the White-throated Swift, and the mysterious Black Swift.
KNOWN FOR
Like their names, swifts are known for their rapid flight. Aerialists such as the Chimney Swift are often seen in the skies above towns and cities as they spend hours on the wing, twittering and foraging in the sky.
PHYSICAL
The Chimney Swift has been called the “flying cigar”; a fairly accurate description of the shape of its tubular body, short tail, rounded head, and long, thin pointed wings. Most swifts share this body shape with slight differences in their wings and tails. Their legs are extremely short and their small feet adapted to clinging on vertical perches. The bills of swifts are also extremely short with wide gapes.
COLORATION
Swifts have dark plumages, either black or dark brown with gray highlights. Some species have white markings on the body and face, but most have very similar dark plumages which, when combined with their fast flight, can make them difficult to identify.
GEOGRAPHIC HABITAT
Swifts occur in the skies above a variety of North American habitats except for the boreal zone and the tundra. In the eastern United States and Canada, the Chimney Swift is the only commonly occurring species and is very common due to it having become adapted to nesting in chimneys and other human-made structures. It is replaced on the west coast by the Vaux’s Swift, and in the Rocky Mountains by the White-throated Swift. In the Pacific Northwest, the Black Swift occurs where waterfalls provide nesting sites.
MIGRATION
Although the White-throated Swift is a short distance migrant, other North American species migrate to Central and South America.
HABITS
Swifts are social birds that typically nest in colonies and are often seen foraging in flocks. Foraging takes place on the wing with birds fluttering high overhead and quickly flying back and forth to harvest “aerial plankton” – the multitude of insects and other arthropods blown into the air by winds and essentially “trapped” in the sky by updrafts. Before and during rainstorms, swifts fly lower to capture insects that are likewise flying lower.
CONSERVATION
While other swifts are common, the Black Swift has suffered population declines. Although it isn’t endangered yet, conservationists are concerned because these declines have occurred in a core area of its range (British Columbia) and very little is known about its natural history, including its wintering range, that would help to formulate implement conservation plans.
INTERESTING FACTS
The Black Swift nests and roosts behind waterfalls. Since these birds are often too difficult to see as they forage high up in the air, a good way to see this species is to watch for them zipping in and out of one of their waterfall roosting sites at dawn or dusk.