Chestnut-collared Swift

The chestnut-collared swift (Streptoprocne rutila) is a species of bird in subfamily Cypseloidinae of the swift family Apodidae. It is found from Mexico and Trinidad south to Peru and Bolivia. == Taxonomy and systematics == The chestnut-collared swift has at various times been placed in genera Cypseloides and Chaetura. These three subspecies are recognized: S. r. griseifrons (Nelson, 1900) S. r. brunnitorques (Lafresnaye, 1844) S. r. rutila (Vieillot, 1817) Subspecies S. r. brunnitorques has been treated as a separate species, but it is now (2020) suspected of not being even a separate subspecies, as "no clear diagnosis of distinctions between brunnitorques and rutila has been published." == Description == The chesnut-collared swift is one of the smaller members of genus Streptoprocne. It is 12 to 14 cm (4.7 to 5.5 in) long and weighs about 21 g (0.74 oz). It has a wide slightly notched tail and broad wings. Adult males of the nominate subspecies S. r. rutila have a sooty blackish brown crown, a blackish brown back, slightly paler rump and uppertail coverts, and a sooty blackish brown tail. They have a narrow black patch around the eye and grayish brown cheeks, chin, and throat with some dull rufous…