Sick’s Swift

Identification

Sick's swift is a medium-sized swift with distinctive plumage that makes field identification straightforward within its breeding range. The upperparts are dark smoky brown, while the tail is ashy grey with dark shafts and characteristic protruding spines. The throat is grey and contrasts with the dark brown of the lower underparts. The bill and legs are black. These features, particularly the grey throat and ashy tail, separate it from related Chaetura species.

Range & Habitat

This migratory species breeds in south-eastern Brazil and adjacent parts of Argentina, Paraguay, and Bolivia. After breeding, it migrates north to overwinter in the Amazon basin, northern South America, and Panama, though its exact wintering range remains poorly documented due to the difficulty of distinguishing similar Chaetura swifts in the field. Records exist from Colombia, Venezuela, Suriname, and French Guiana. Sick's swift favours lowland evergreen forest edges, secondary forest, open woodland, and second-growth scrub, though it can be observed flying over virtually any habitat during migration.

Behaviour & Diet

Sick's swift is an insectivore, capturing flying insects in flight. It typically hunts low over roads and forest clearings in early morning and evening, then rises high above the canopy during mid-day, often joining other swifts. The breeding season coincides with the transition from the dry season to the rainy season. Nests are built in chimneys or hollow trees, constructed almost entirely from 5 cm dry leaf stalks bound with adhesive saliva. The open cup design lacks a rear wall, which is formed by the tree itself. Clutch sizes range from 3–5 eggs; females incubate while both parents feed the young. Nests are reused until they deteriorate, after which new ones are built in the same location.

Best Time & Places to See It

Within its breeding range in south-eastern Brazil, northern Argentina, Paraguay, and Bolivia, Sick's swift is generally common and relatively easy to identify as it is the only large Chaetura swift in these areas. Observers should watch for the species in lowland forest edges and open woodlands during the breeding season. Early mornings and evenings offer the best viewing opportunities when birds fly lower over clearings and roads. During migration periods, sightings in northern South America and Panama are possible but less frequent.

Photography Tips

Photographing Sick's swift presents the classic challenges of swift photography: rapid, acrobatic flight and small size require fast shutter speeds (at least 1/2000s) and good tracking skills. Early morning and evening hunts over open areas and clearings provide better opportunities than mid-day when birds soar high above the forest. Focus on identifying the distinctive ashy-grey tail with protruding spines and grey throat, which are key diagnostic features. Patient observation of favourite feeding routes and times will increase your chances of capturing this agile flier in flight.