White-collared Swift

The White-collared Swift, Streptoprocne zonaris, is a striking bird, the largest of its kind within its territory, save for the White-naped Swift in northwestern Mexico where their ranges overlap. This swift measures from 20 to 21.5 cm in length and tips the scales at 90 to 125 grams. Its wingspan is an impressive 45 to 55 cm. Both sexes are adorned with similar plumage, featuring a distinctive white collar that encircles the neck, broadening across the breast. The bird's forehead is a sooty hue, with the head a dark sooty black, and the tail a grayish black. The plumage is predominantly black with a subtle blue gloss on the back, rump, and uppertail coverts. Juveniles present a duller, sootier appearance with grayish white to white tips on their body feathers.

Identification Tips

To identify the White-collared Swift, look for its very slightly forked tail and the uniform plumage between the sexes. The adult's white collar is a key feature, along with the sooty forehead and the blue gloss on the upper parts. Juveniles can be distinguished by their duller coloration and the white tipping on their feathers.

Habitat

This swift is quite adaptable, commonly seen soaring over montane and submontane evergreen forests, but also inhabiting lowland evergreen forests, secondary forests, and even open scrublands. It ranges from sea level to elevations as high as 3,600 meters.

Distribution

The White-collared Swift is widespread, found from southern Mexico through Central America, across the Greater and Lesser Antilles, Trinidad, and throughout South America, with the exception of Chile. It has been noted as a vagrant in locations such as Aruba, Texas, Florida, and even as far north as Michigan.

Behaviour

Considered resident throughout its range, the White-collared Swift has been known to venture beyond its usual northern limits and to make significant movements to lower elevations during inclement weather.

Song & Calls

The swift's vocal repertoire includes a nasal twitter of "chee chee chee, whiss whiss" and "scratchy but not shrill tseet, tchee, and chirrio notes". When in flocks, these swifts may call in unison, creating a symphony of swift song.

Breeding

Breeding activities have been documented in southern Mexico and Costa Rica during April and May, with colonies nesting in caves, often near streams or waterfalls. The nests are constructed from mud, moss, and insect chitin, lined with leaves or fern fronds, and vary in composition between colonies. Clutch size is typically two eggs, though incubation periods and fledging times remain a mystery.

Similar Species

The White-naped Swift is similar in appearance but slightly larger and shares part of its range with the White-collared Swift in northwestern Mexico.

Diet and Feeding

As aerial insectivores, these swifts feed primarily on flying insects, with a particular fondness for flying ants. They are often seen feeding in large flocks, sometimes alongside other swift species, and are known for their powerful, fast, and direct flight, reaching speeds of 70 to 100 km/h.

Conservation status

The IUCN has classified the White-collared Swift as Least Concern. With an estimated population of over five million mature individuals and an extensive range, the species does not currently face any immediate threats, and human impact appears to be minimal. However, the population is believed to be in decline.