The great dusky swift is a species of bird in subfamily Cypseloidinae of the swift family Apodidae. It is found in Argentina, Brazil, Paraguay, and possibly Bolivia.
Region
Southern Atlantic Forest
Typical Environment
Occurs in southeastern South America, mainly in Brazil, northeastern Argentina (Misiones), eastern Paraguay, and possibly adjacent Bolivia. It favors escarpments, gorges, and moist evergreen forest where large waterfalls provide sheltered, spray-soaked ledges for nesting. Away from breeding sites it forages widely above forest canopies, along rivers, and across adjacent open country. The species is closely tied to waterfall systems but ranges broadly in the surrounding lowlands and foothills.
Altitude Range
Sea level to 1500 m
Climate Zone
Subtropical
Ease of Keeping
Beginner friendly: 1/5
This swift famously nests behind large waterfalls such as Iguazu Falls, clinging to perpetually wet rock faces where few predators can reach. It spends most of its life on the wing, catching insects over forests and rivers and only landing to roost or nest. Colonies can number in the hundreds, swirling dramatically through waterfall spray at dawn and dusk.
Great dusky swift on nest
Temperament
social and active
Flight Pattern
powerful flier with rapid, stiff wingbeats and short glides
Social Behavior
Breeds colonially on vertical, wet cliffs behind waterfalls, attaching mossy cup nests to the spray-soaked rock. Pairs are monogamous within a season and share incubation and chick rearing. Outside breeding, it gathers in sizable flocks that roost near falls and forage widely over surrounding landscapes.
Migratory Pattern
Resident
Song Description
Vocalizations are high, thin chips and insect-like trills, often given in flight over colonies. Around waterfalls, calls can sound sharp and piercing to cut through the ambient roar.
Plumage
Uniformly sooty-brown to dark chocolate with subtle pale edging on body feathers that can give a slightly scaled look when fresh. Long, narrow, sickle-shaped wings and a shallowly notched tail. Throat may appear marginally paler in good light.
Diet
Feeds almost exclusively on aerial insects, including flies, ants, termites, beetles, and small wasps caught on the wing. It forages at varying heights, from just above the canopy to high in the air, often following insect swarms. During favorable conditions it ranges far from nesting sites to exploit concentrated prey.
Preferred Environment
Commonly hunts above forested river valleys, open forest edges, and over broad rivers and waterfalls where emergent insects are abundant. It also forages over nearby clearings and towns after storms that bring insects low.
