Seasonal and Maturational Pelage Changes, and Injuries, in the Eastern Water Rat, Hydromys chrysogaster, at Griffith N. S. W.

Abstract

Pelage changes in the water rat were followed in skins collected at Griffith, N.S.W. Females moulted in autumn and summer, and some may have moulted in spring. Males moulted in autumn and summer only. The summer coat was sparse and coarse, the winter coat was dense and fine. A diffuse moult sometimes followed the autumn moult. The majority of moults were of the sheet (or wave) type and hair replacement proceeded dorsad-caudad. An animal's first two or three moults were rapid and related to age, and at about 6 months of age were replaced by a less rapid, seasonal moult. A diffuse type of moult became more common with age, especially in males, in which it almost entirely replaced the summer sheet moult. Changes in the quality of pelt, the timing, type and extent of moult, and injuries due to fighting are discussed in relation to photoperiod, temperature, reproductive condition, adrenal weight, body condition and social interaction.