The sheer size of these enormous hummingbirds along with their slow wing beats identifies them in the field. Males are greenish teal with mostly blue wings. Females are green above, cinnamon below, and have blue on the upper wing. Both males and females have forked tails. Great Sapphirewings usually feed by themselves at flowers at low or medium levels in the forest; sometimes, however, they join mixed species flocks when foraging. They inhabit cloud forests, forest edges, elfin forests, shrubby slopes, and grassy areas in páramo habitat. Early in the morning, they often perch high on leafless branches.