Very poorly known species that is known only from a few specimens from eastern Congo. Medium-sized, uniformly blackish-gray swift with a long, thin tail. Found over and around forest at middle elevations. Very similar to Scarce Swift, and separation is poorly understood, but Schouteden’s is darker overall, without a contrastingly paler throat. Similar to African Palm Swift, but darker. Very similar in shape to White-rumped Swift, but lacks white throat and rump patches. Can be mistaken for other swift species such as African and Common Swifts, but has a slimmer body, a longer and slimmer tail, and a less powerful flight style.