In the mountains around Bogotá it is very difficult to distinguish the glossy "picaflor" from the resident subspecies of the black hummingbird (Diglossa humeralis humeralis). Both are black with gray shoulders. Although these black hummingbirds are distinguished from the glossy ones by having the gray rump, it is rarely visible in the field, so it is not a very useful mark to separate species. As both hummingbirds live in the midst of thick vegetation and move in the branches incessantly, it will often be impossible to know which species we are observing. However, with experience, patience and a bit of luck, it is possible to distinguish the two hummingbirds: the glossy hummingbird, besides being somewhat larger, has a little more hooked beak and the base of the jaw more prominent than the black hummingbird .Taken from: opEPA
