不育调控的布氏田鼠种群内占位竞争和繁殖干扰机制

Fertility control is one of the hot technologies in management of pest rodents in the last decade, which could contribute significantly to benign, sustainable, and little adverse-effects rodent-management strategies. Up to present, little is known about the mechanisms of anti-fertility treatments for rodents at the population level. In this project, quinestrol will be delivered by oral gavage to 80% male and female Brandt's voles in an enclosed population. population density and structure characteristic will be monitored for 3 years, and building a model of Brandt's vole populations subjected for one generation to 80-percent sterilization of both sexes for 3 years, test Knipling's theory that sterilizing both sexes of an organism in a natural population is inherently more advantageous than conventional killing for suppressing both vertebrate and invertebrate pest animals population density. At the same time, the social behavior including possessiveness of territories, mating and dispersal behaviors of control and treated animals will be recorded using digital video. By combining kinship assignments and different levels of relatedness measures, the mating and dispersal patterns will be assessed using microsatellite DNA markers and capture-mark-recapture, social behaviors, reproduction characters data will be used to test and verify the theories of ecology competition and interfere with the reproduction of normal individuals through social competition with infertile individuals. And population genetic structure will be then used to provide an insight into the genetic bottleneck effects on the population. This project aimed to analysis the suppression effects and mechanisms of quinestrol on enclosed Brandt's vole population. The results will rich the ecological theory of fertility control in mammals, and advance the infertility control in the field practice.

不育控制是最近10年国内外关注的人道、可持续、负作用小的鼠害控制热点技术之一。但到目前为止，对啮齿动物种群水平上的不育处理后果的机理解析仍显不足。本研究以双性不育剂炔雌醚处理围栏内布氏田鼠种群80%个体，监测种群的数量、结构变化3年，建立双性不育布氏田鼠种群的较长期发展模型，验证Knipling不育比传统的灭杀更能达到控制种群数量的理论假说；摄像观察社群中不育个体与正常个体间的领域、交配等社会行为，用微卫星DNA标记手段结合标记重捕技术确定不育和对照种群的家系结构、扩散和婚配方式差异，从种群的社会行为、繁殖特点等方面解析验证不育控制的占位竞争和繁殖干扰理论；分析不育种群遗传结构的变化，估测不育控制的可能遗传瓶颈效应。项目结果将系统阐释不育对种群的影响及其原理，丰富不育控制生态理论，为实际鼠害不育控制措施的试验推广奠定坚实基础。

不育控制是近10年国内外关注的人道、可持续、负作用小的鼠害控制热点技术之一。但到目前为止，对啮齿动物种群水平上的不育处理后果的机理解析不足。本研究以双性不育剂炔雌醚处理围栏内布氏田鼠种群70%个体，监测了种群的数量、结构变化3年；同时摄像观察社群中不育个体与正常个体间的领域、扩散和交配等社会行为；用微卫星DNA标记手段结合标记重捕技术确定了不育和对照种群的家系结构、越冬和婚配方式差异。从种群的社会行为、繁殖特点和生活史等方面解析验证不育控制的种群效应。最终，我们测定了炔雌醚对布氏田鼠繁殖抑制最适剂量为1 mg/kg左右，其持续有效作用时间可达90天。炔雌醚不育处理布氏田鼠种群的繁殖启动期推迟约15-30天，繁殖高峰期延迟40天左右。不育处理雌雄布氏田鼠的社群行为和扩散行为无明显变异，但交配持续时间显著延长。布氏田鼠种群的越冬和繁殖对策研究结果显示，寿命周期一般为1年的布氏田鼠，每年越冬鼠是种群后代遗传物质的主要贡献者，是次年种群发展的基础，不育鼠的后代越冬存活率显著下降，这将导致次年基础种群密度较低。但布氏田鼠的同胞鼠具有均等的越冬和成功繁殖几率，同胞鼠个体能否越冬和参与繁殖与否是随机的。加之该种混交制的婚配繁殖制度，即使少量的鼠具有繁殖能力，其繁殖后代的数量也不会大幅下降。对于该鼠野外不育控制的关键点是保持种群足够高的不育率和不育持续时间应能够覆盖整个繁殖期（4月-8月），这要求不育药饵具有很高的取食有效性和相应的投放频次。