Seasonal moulting patterns in three fur bearing mammals: the European badger (Meles meles L.), the red fox (Vulpes vulpes L.), and the mink (Mustela vison). A morphological and histological study

Seasonal changes in the fur of three species of mammals at the adult stage, the European badger, the red fox, and the mink, were studied in the field. The badger had only one seasonal change of pelage during the summer and the fall (from July to December), and there was no seasonal variation of hair density. The fox moulted in the spring (between the end of April and the end of August) and again in the fall, but the fall change consisted only in the regrowth of a new fine undercoat that combined with the summer fur to form a denser winter coat. In the mink, the spring and fall moults were very distinct and gave rise to characteristic summer and winter coats that differed in density and number of fine hairs per surface unit. The histological study revealed a similarity in skin composition among the three species, but the relative importance of the different components (sebaceous glands, adipose tissue, keratine layer) varied with each species' way of life. Seasonal follicular activity was correlated with seasonal regrowth of the pelage; the active anagen phase was very long (badger, 5 months; fox, 4 months; mink, 2 months in the spring and 3 months in the fall). During the other part of the annual cycle, telogen, the hair follicles were in a resting phase. Differences in the annual moulting processes between the three species are discussed in terms of adaptive characteristics.[Journal translation]