关键词: 蒙新河狸, 人工饲养, 繁殖, 交配行为

Abstract: According to behavioral characteristics，oestrous cycle of Xinjiang-Mongolia beaver
(Castor fiber birulai Serebrennikov)can be didided into 4 phases:proestrus，oestrus
metaestrus and anestrus．In proedtrus，beavers appear to be active and noisy，and food-taking decrease:In oestrus，both sexes initiate vocalization of special characteristics which is named 'Oestrous vocalization'.The frequency of males' vocalization is higher than femaled'，though it is hard to distinguish．During copulation，the males appear to be more active and its food-taking decrease more significantly，while the females' food-taking increase slightly．The ’oestrous vocalization and other behavior may serve as significant symbols to identify phases of oestrous cycle．Oestrus and copulation occur normallyin Xinjiang-Monglia beaver under rearing conditions．Copulation may occur on either land or water．

Key words: Xinjiang-Monglia beavre(Caster fiber birulai), Breeding, Reproduction, Copulation behavior