关键词: 麻阳河国家级自然保护区, 黑叶猴, 野外投食群, 动态观察

Abstract: From 2009 to 2021, a direct observation method was used to track and monitor a provisioned group of Trachypithecus francoisi in Mayanghe National Nature Reserve. The observation period covered 1 846 days with an average annual working days of 142. In total, 31 adults (15 males, 16 females) were observed and, in addition, 26 babies were born with a male-female ratio of 1.2∶1 (14 male, 12 female) of which 15 infants survived (7 males, 8 females), a survival rate of 57.7%. For the whole group, the average annual monkey group birth rate was about 22.8% and the annual loss rate was about 11.4%. The number of births exhibited a bimodal distribution, peaking from February to April and from July to October. The average reproductive interval of adult monkeys was 18.7 months but shortened to 16.3 months after the death or disappearance of a newborn. During 2019 -2021, the average growth rate of the group was 11.4%, the number of monkeys had generally stabilized and was self-sustaining. However, as of the end of December 2021, the feeding group had dwindled to just nine individuals (two males and seven females) due to individual deaths, disappearances, and expulsions of some sub-adults. There were no infants or juveniles and insufficient sub-adults. Furthermore, the proportion of middle-aged and elderly individuals was high, resulting in an imbalanced age structure. This study provides basic data related to long-term monitoring of wild Trachypithecus francoisi in Mayanghe National Nature Reserve. This has provided an important basis for follow-up scientific research, educational projects, and monitoring and management of Trachypithecus francoisi in the reserve. Moreover, it has ensured that this flagship species and its habitats are effectively protected and sustainably used, so as to promote the high-quality development of biodiversity protection in this region.

Key words: Mayanghe National Nature Reserve, Trachypithecus francoisi, Provisioned group in the wild, Dynamic observation