A method is described by which it is made possible to recognize the individuals of populations of Accipiter hawks. A set of morphological characteristics of moulted primaries (length, shape, pattern of pigmentation, colour and diameter of rhachis) have been found to show considerable variation among individuals. On the other hand, these features are closely similar in feathers from consecutive moults of any given bird. Differences in feather morphology between yearlings and adults are described. The feasibility of the method in population studies is discussed.