Dark, mid-sized swift with powerful, direct flight. Can be seen in flight over any habitat, including towns and cities. Often in flocks of dozens or hundreds that sometimes also contain Alpine Swifts. Larger size and stronger flight distinguish Madagascar Swift from most other swifts in the region. Smaller than Alpine Swift, with a dark belly. Very similar to vagrant Common Swift, but has contrastingly pale panels at the bases of the wings, adjacent to the body.