In the field of archaeo-zoology, it is quite often a problem to distinguish between domestic and wild geese according to their bones, and this makes it difficult to obtain an accurate assessment of supply options in the sites studied. This paper, based on the osteometrical data from the medieval castle of Boves and from a set of neighbouring settlements of the same period, suggests a method to estimate the ratio of game to poultry. With the help of the Log Size Index technique and of the Simpson diagrams, the archaeological remains are compared with a reference collection of modern bones from domestic and barnacle geese. The results produced here show that there are certain metric criteria for the identification of domestic and game birds, and that it is possible to work out the relative proportions of each group on different medieval sites. Thus this first study helps to establish the outline of the medieval goose with more precision, and to get a better understanding of the management of meat resources. Traduction : Margaret & Jean-louis CADOUX