Andreassen Harry P, Gundersen Gry
Faculty of Forestry and Wildlife Management, Hedmark University College, Koppang, Norway.
Ecology. 2006 Jan;87(1):88-94. doi: 10.1890/04-1574.
Turnover of individuals is assumed to cause disruptions of social organization, followed by reduced reproduction and survival. We tested how male turnover (removal of resident males and their replacement by unfamiliar males) affected population performance in experimental root vole (Microtus oeconomus) populations. The treatment simulated predation of adult males, with the subsequent replacement by immigrants, and provided insight into the interaction between extrinsic (i.e., predation) and intrinsic (i.e., social organization) factors. We showed that recruitment and female survival dramatically declined and that reproduction commenced slightly later in treatment populations compared with control populations. The treatment nearly halved the population growth rate. We suspect that recruitment failed due to infanticidal immigrating males. Reduced female survival was particularly apparent in treatment populations in which females exhibited a high degree of spatial overlap. Our experimental results show how males may significantly shape population dynamics and suggest how predation and social factors interact mechanistically.
个体更替被认为会导致社会组织的瓦解，进而导致繁殖和生存能力下降。我们测试了雄性更替（将常驻雄性移除并用陌生雄性替代）如何影响实验性根田鼠（Microtus oeconomus）种群的种群表现。该处理模拟了成年雄性被捕食，随后由移民替代，从而深入了解外在（即捕食）和内在（即社会组织）因素之间的相互作用。我们发现，与对照种群相比，处理种群中的招募和雌性存活率显著下降，繁殖开始时间稍晚。该处理使种群增长率几乎减半。我们怀疑招募失败是由于杀婴的移民雄性。雌性存活率降低在雌性表现出高度空间重叠的处理种群中尤为明显。我们的实验结果表明了雄性如何显著影响种群动态，并揭示了捕食和社会因素如何在机制上相互作用。
