White-thighed Swallow

The white-thighed swallow averages about 12 cm (4.7 in) long and weighs 8.5 to 14 g (0.30 to 0.49 oz). The sexes have the same plumage. Adults of the nominate subspecies A. t. tibialis have a brownish black head with a slight green sheen, black lores, and gray-brown cheeks and throat. Their back is brownish black with a slight green sheen and their rump gray-brown. Their tail is slightly forked and brownish black. Their wings are mostly brownish black with slightly lighter tips on the greater coverts and tertials. Their underparts are gray-brown with the eponymous white feather tufts on their lower legs. Subspecies A. t. minima is smaller and overall darker than the nominate. A. t. griseiventris is larger and glossier than the nominate, with a grayer rump and underparts. All subspecies generally have a dark brown iris, bill, and legs and feet, though a few individuals of A. t. minima have differed.

The white-thighed swallow has a disjunct distribution, with each subspecies being separate from the others. They are found thus:

Atticora tibialis minima: from Coclé Province in central Panama south through western Colombia into western Ecuador as far as western Azuay Province Atticora tibialis griseiventris: from Venezuela's southern Bolívar and eastern Amazonas states south across a bit of northwestern Brazil, eastern and southern Colombia, eastern Ecuador, and eastern Peru into northern Bolivia and east across Brazil south of the Amazon River Separately from extreme eastern Guyana east through Suriname into French Guiana Atticora tibialis tibialis: southeastern Brazil mostly from southern Bahia south to eastern São Paulo state with records as far north as Pernambuco The white-thighed swallow primarily inhabits the edges and clearings of lowland evergreen forest in the tropical zone. It also occurs in more open country with scattered trees and along rivers. In elevation overall it ranges from sea level to about 1,200 m (3,900 ft). In Colombia it reaches 1,100 m (3,600 ft), in western Ecuador 800 m (2,600 ft), in eastern Ecuador and Peru 1,250 m (4,100 ft), in Venezuela 900 m (3,000 ft), and in Brazil mostly to 1,000 m (3,300 ft) and locally higher.

The white-thighed swallow feeds on insects captured on the wing, and is usually seen in pairs or small flocks. Though details of its diet are lacking, it is known to include beetles (Coleoptera), true bugs (Hemiptera), and members of Hymenoptera.