洞庭湖区域黑线姬鼠（Apodemus agrarius）种群迁入湖滩后的繁殖特征

黑线姬鼠(Apodemus agrarius)是广泛分布于我国的主要农田害鼠之一,2003年三峡工程开始蓄水后洞庭湖湖滩鼠类群落结构发生了演变,黑线姬鼠已大量侵入湖滩,且逐步成为湖滩生境鼠类群落的优势鼠种。动物在新生境中的繁殖状况是了解其对环境适应的关键指标。为掌握黑线姬鼠种群侵入湖滩生境后的适应情况,为其种群动态的预测预报提供科学依据,本文对2003—2020年洞庭湖湖滩和农田生境中捕获的黑线姬鼠繁殖状况进行比较分析,并结合季节动态和生境差异等因子分析了该鼠在繁殖方面对湖滩生境的适应。结果表明:(1)湖滩生境中黑线姬鼠平均繁殖指数(0.71±0.27)低于农田生境(1.21±0.47),在2016—2020年湖滩上黑线姬鼠的繁殖指数为0.99,略高于农田的0.96;(2)湖滩生境较农田生境中的孕鼠在繁殖中偏向有更多的胎仔数,有6只以上胎仔数的孕鼠占比(65.59%)高于农田生境(49.10%);(3)湖滩生境中发现有幼年组的黑线姬鼠参与繁殖,其繁殖指数、参产率、怀孕率及雄鼠的睾丸下降率随年龄递增;(4)春季和秋季是湖滩生境中黑线姬鼠的主要繁殖季节,其繁殖指数、参产率、怀孕率都显著高于...

The reproductive status of Apodemus agrarius populations inhabiting the lake beach in Lake Dongting area after Three Gorges Project

Apodemus agrarius is one of the important pest rodents in farmland and broadly distributes in China. Since the establishment of the Three Gorges Project in 2003, the structure of rodent community has been evolving in Lake Dongting beach. A large number of A. agrarius has invaded the lake beach, and gradually dominated the community. The status of animals reproductive in a new habitat is one of the key indicator for understanding their adaptation to environment. It may provide scientific basis for further understanding the adaptation mechanism of A. agrarius after its invasion. It is also useful for the prediction and ecological prevention of A. agrarius. This study provided a comparative analysis of the reproductive status of A. agrarius caught in the lake beach and farmland habitat during 2003-2020 in Lake Dongting area, and analyzed their adaptability to the lake beach habitat in terms of reproduction in combination with seasonal dynamics and habitat differences. The results showed that: (1) The average reproductive index of A. agrarius was 0.71±0.27, which was lower than 1.21±0.47 in the farmland habitat. The reproductive index of A. agrarius on the lake beach during 2016-2020 was 0.99, which was slightly higher than 0.96 in the farmland. (2) Pregnant mice in the lake beach habitat tended to have more offspring than those in the farmland habitat, and the proportion of pregnant mice with more than 6 fetuses (65.59%) was higher than that in the farmland habitat (49.10%). (3) Juveniles were found to be involved in reproduction in the lake beach habitat, and their reproductive index, participation rate, pregnancy rate, and the rate of testes in scrotum increased with age. (4) Spring and autumn were the main breeding seasons for A. agrarius in the lake beach habitat. Its reproductive index, the rate of breeding female and rate of pregnancy were significantly higher than those in summer and winter, while the female-male ratio was significantly lower than that in summer. (5) Different vegetation structures in the lake beach habitat had an effect on the reproduction of A. agrarius, and the reproductive ability of the A. agrarius was stronger in the lake beach habitat of Carex sp.+ Miscanthus sp., and weaker in the reed land and wood land. These results suggested that the A. agrarius had adapted to the lake beach habitat and there were some difference in reproductive characteristics of the beach habitats compared with those of traditional farmland habitats.