利用成幼比分析近20年野骆驼种群结构变化

The Ratio of Adults to Calves/Sub-Adults Reveals Population Structure Dynamics of Wild Bactrian Camel Over the Past 20 Years

野骆驼(Camelus ferus)是我国一级重点保护野生动物,被IUCN列为极危级物种。新疆罗布泊野骆驼国家级自然保护区是我国野骆驼分布的集中区域,由于野骆驼生存的自然条件极其恶劣,对其种群现状和动态的研究一直较为困难。本研究于2021年和2022年采用样线法对保护区内野骆驼种群开展调查,并比较了近20年野骆驼群体平均个体数量和种群成幼比,分析其种群结构变化。本次野外调查共记录野骆驼29群148峰,2010至2013年调查共记录野骆驼94群376峰,2003至2005年调查共记录野骆驼10群91峰。3个调查阶段,2峰及以上野骆驼群的平均个体数量无显著差异,10峰及以上野骆驼群的平均个体数量也无显著差异。选择野骆驼个体数量10峰及以上的野骆驼群进行分析,结果显示,本次调查与2010至2013年调查,野骆驼的成幼比均稳定在3︰1,2003至2005年野骆驼的成幼比为3.6︰1。从成幼比来看,近10年野骆驼种群结构基本稳定,较20年前野骆驼种群结构更趋于健康,此研究结论与当前保护区野骆驼种群数量增长的趋势相一致。本文对野骆驼种群结构变化的研究,一定程度上反映了野骆驼的种群动态和保护成效,可为我国野骆驼的保护与种群管理提供科学依据。

[Objectives]The Wild Camel Camelus ferus is listed as Class I national key protected wild animal and a critically endangered species by the IUCN.Xinjiang Lop Nur Wild Camel National Nature Reserve is the main distribution area of Wild Camels in China.Due to the extremely harsh environment,it is difficult to study the current status and dynamics of Wild Camel population.[Methods]In this study,we investigated the Wild Camel population through line transects in the protected area during 2021﹣2022.The number of adults and calves/sub-adults camels were recorded during the surveys(Fig.1).One-way ANOVA was used to compare the average group size among different surveys.The abundance index per kilometer and the ratio of adults to calves/sub-adults over the past 20 years were compared,followed by an analysis of the changes in Wild Camel population structure.[Results]A total of 148 camels belonging to 29 populations were recorded in the 2021﹣2022 field survey(Table 1),with almost all the Wild Camels found in the gobi area north of Altun Mountains except one individual(Fig.2),while 376 camels belonging to 94 populations recorded in the 2010﹣2013 field survey,and 91 camels belonging to 10 populations recorded in the 2003﹣2005 field survey.There was no significant difference in the average group size with more than or equal to 2 or 10 Wild Camels among the three surveys.Regarding groups with more than or equal to 10 Wild Camels,the results showed that the ratio of adults to calves/sub-adults in 2021﹣2022 and 2010﹣2013 was 3︰1,and that of Wild Camels in 2003﹣2005 was 3.6︰1(Table 2).[Conclusion]The population structure of Wild Camels has remained stable over the past 10 years,which is healthier than it was 20 years ago.Our conclusion is also consistent with the current growth trend of Wild Camel population in the protected area.The study on the changes of Wild Camel population structure reflects the population dynamics and conservation effectiveness of Wild Camel to a certain degree,and provides scientific guidance for the population conservation and management of Wild Camel in China.