White-collared Swift

The white-collared swift is the largest species of swift in its range except in northwestern Mexico, where it and the slightly larger white-naped swift (S. semicollaris) are sympatric. The white-collared swift is 20 to 21.5 cm (7.9 to 8.5 in) long and weighs 90 to 125 g (3.2 to 4.4 oz). It has a wingspan of 45 to 55 cm (18 to 22 in). It has a very slightly forked tail and the sexes have the same plumage. Adults have a white collar that circles the neck and is broadest on the breast. Their forehead is sooty, most of the head dark sooty black, the tail grayish black, and the rest of the plumage black. The back, rump, and uppertail coverts have a slight blue gloss. Juveniles are duller and sootier than adults and have grayish white to white tips on most of their body feathers. There are minor differences among the subspecies in the width of the white collar, the shades of black on the body and tail, and the amount of white fringing on the juvenile.

The subspecies of the white-collared swift are found thus:

S. z. mexicana, from Guerrero and Veracruz in southern Mexico south into Guatemala and Belize S. z. bouchellii, from Honduras and El Salvador through Nicaragua and Costa Rica into Panama S. z. pallidifrons, the Greater and Lesser Antilles S. z. minor, the Coastal Ranges of Venezuela; Trinidad; vagrant to Tobago S. z. albicincta, inland Venezuela and the Guianas S. z. subtropicalis, from western Venezuela in the Andes through Colombia and Ecuador into Peru S. z. altissima, high Andes of Colombia and Ecuador S. z. kuenzeli, high Andes of Argentina, Bolivia, and Chile S. z. zonaris, Bolivia, southern Brazil, and Paraguay; vagrant to Uruguay The species has also been noted as a vagrant on Aruba but which subspecies is not known. Further north it has also occurred as a documented vagrant in Texas and Florida and there are sight records from California, Michigan, and several locations in northern Mexico. The white-collared swift inhabits a large variety of landscapes. It is most common over montane and submontane evergreen forests, and is also found over lowland evergreen forests, secondary forests, and more open habitats like scrublands. In elevation, it ranges from lowlands to 3,600 m (11,800 ft).

Like all swifts, the white-collared is an aerial insectivore. Details of its diet are lacking, but a pair of specimens from southern Mexico had fed almost exclusively on flying ants. It often feeds in flocks of 200 or more that sometimes include other swift species. It has a powerful, fast, and direct flight, and will ascend thermals to great heights. White-collared swifts attain or exceed flying speeds of 70 to 100 km/h (43 to 62 mph).