A dark-brown swift, it catches insects above forests and uses rocky waterfalls for resting and breeding.
It has dark-brown plumage with a paler forehead and rump, long broad wings, and a square to slightly rounded tail.
It catches flying insects above forest and uses waterfall cliffs for resting and nesting.
At Brazil’s Caracol Falls, 42 moss-and-mud nests at the water curtain were reported, each with one egg.
At Aratinga, Brazil, in November 2008, 15–20 Great Dusky Swifts flew with 5–8 White-collared Swifts over secondary forest, fields and pine plantations.
An extinction-risk assessment has not been added yet.