果洛州高寒草甸青海田鼠种群年龄划分及年龄结构季节性特征

Age determination and structure characteristics ofQinghai vole population composition in the alpinemeadows of Guoluo Prefecture

摘要:

【目的】 建立青海田鼠（Lasiopodomy sfuscus）年龄组划分标准，为其监测及防控提供科学依据。【方法】 于2021 年7 月至2022 年6 月在果洛藏族自治州玛沁县共采集935 例青海田鼠个体样本，利用系统聚类法对其体重和胴体重进行分析，通过体长、尾长、耳长和后足长为辅助指标来划分青海田鼠年龄结构，分析不同季节青海田鼠的种群结构特征。【结果】 捕获到的青海田鼠可划分为5 个年龄组，即幼年组（Ⅰ龄组，雄性胴体重≤18 g，雌性胴体重≤12 g）、亚成体组（Ⅱ龄组，18 g＜雄性胴体重≤25 g，12 g＜雌性胴体重≤21 g）、成年Ⅰ组（Ⅲ龄组，25 g＜雄性胴体重≤34 g，21 g＜雌性胴体重≤27 g）、成年Ⅱ组（Ⅳ龄组，34 g＜雄性胴体重≤42 g，27 g＜雌性胴体重≤36 g）、老年组（Ⅴ龄组，雄性胴体重＞42 g，雌性胴体重＞36 g）；青海田鼠种群结构有明显的季节性特征，1-2 月为冬眠期，只有极少数越冬成年个体活动，3 月初开始进入繁殖期，种群主要以幼年体、亚成体和成年体为主，7-8 月达到繁殖高峰，亚成体和成年体比例增大，并在10 月份结束繁殖，种群主要以成体和老年体为主。【结论】 采用胴体重对青海田鼠种群年龄进行划分最具有代表性。本研究填补了我国青海田鼠年龄鉴定标准的空白，为其种群生物学和生态学特征研究提供了基础数据。

Abstract:

【Objective】 The Qinghai vole（ Lasiopodomy sfuscus） is a unique rodent in the Qinghai Tibet Plateau. Establishing an age group classification standard for Qinghai voles can provide scientific basis for its monitoring，preventionand control.【Method】 This study was conducted from July 2021 to June 2022 in Maqin County，Guoluo TibetanAutonomous Prefecture，where a total of 945 individual Qinghai voles were collected. Systematic clusteringanalysis was employed to analyze body weight and body length，using auxiliary measurements such as body length，tail length，ear length，and hind foot length to delineate the age structure of the Qinghai vole. The population structureand reproductive features of the speciesacross different seasonswere also examined in this study.【Result】 The resultsrevealed that the captured Qinghai voles could be classified into five age groups： juvenile group （Ⅰ age group，malecarcass weight ≤ 18 g，female carcass weight≤ 12 g），sub-adult group （Ⅱ age group，18 g ＜ male carcassweight ≤ 25 g，12 g ＜ female carcass weight ≤ 21 g），adult group Ⅰ（ Ⅲ age group，25 g ＜ male carcass weight ≤34 g，21 g ＜ female carcass weight ≤ 27 g），adult group Ⅱ （Ⅳ age group，34 g ＜ male carcass weight ≤ 42 g，27 g ＜ female carcass weight ≤ 36 g），and elderly group（ Ⅴ age group，male carcass weight ＞ 42 g，female carcassweight ＞ 36 g）. Adult and elderly groups were found to be the main contributors to population reproduction. Additionally，the Qinghai vole population structure displayed distinct seasonal variations. The period from January to Februarymarked the hibernation phase，with only a small number of overwintering adult individuals active. Breeding activitiescommenced in early March，primarily driven by juvenile，sub-adult，and adult individuals. The peak breedingseason occurred in July and August，with an increase in the proportion of sub-adult and adult individuals. Breedingconcluded in October，with the population primarily comprised of adult and elderly individuals.【Conclusion】 In summary，using carcass weight to classify the age of Qinghai vole population is the most representativemethod. Thisstudy fills the gap in the age identification criteria for Qinghai voles in China and provides basic data for studying theirpopulation biology and ecological characteristics.