ANNUAL VARIATION IN BODY-COMPOSITION OF ROE DEER (CAPREOLUS-CAPREOLUS) IN MODERATE ENVIRONMENTAL-CONDITIONS

Patterns of growth and seasonal variation in body mass, kidney fat lev el, and bone marrow fat level were investigated in a roe deer populati on south of Paris. Size dimorphism was not apparent until the deer wer e 2 years of age, following a second period of rapid growth in males d uring spring-summer. No differences between the sexes in fat accumulat ion or in the periodicity of the annual fat cycle were observed. Howev er, annual cycles of adult body mass were asynchronous between the sex es. Carcase mass was stable for much of the year, but one marked seaso nal decline was observed in animals of each sex. For females (April-Au gust) this reflected investment in late gestation and lactation, but a mong males (April-November) it was presumably linked to the costs of r utting. Contrary to reports for other ungulates, no over-winter declin e in adult carcase mass, kidney fat level, or bone marrow fat level wa s observed, possibly because winters were mild. All four fat indices ( kidney fat index, three bone-marrow fat indices) declined over spring- summer. This seasonal cyclicity does not match the energy requirements of reproductive activity, suggesting that the fat cycle is intrinsic, linked to seasonal metabolic variation in roe deer. We suggest that c arcase mass is a more reliable index of condition in roe deer.