Baars M A
Netherlands Institute for Sea Research, P.O. Box 59, Texel, The Netherlands.
Oecologia. 1979 Dec;44(1):125-140. doi: 10.1007/BF00346411.
Tracking of individual Ir-labeled ground beetles released in the field revealed that both the day-active and night-active species studied showed periods of small distances covered per day in random directions, alternating with periods of directed movement with large distances covered per day. This pattern occurred not only in the reproductive period but outside the breeding season as well in juvenile Pterostichus versicolor and spent Calathus melanocephalus. Although mean locomotory activity increased with temperature, great daily differences occurred between individuals, pointing to asynchronous behavior. In an unfavorable habitat directed movement occurred both more frequently and more extremely, sometimes resulting in escape to more favorable areas. Most of the radioactive beetles died within 7 weeks due to radiation effects, but independent field experiments and simulations showed that the recorded patterns were valid. Simulated individuals of P. versicolor living on 1 ha spread over 49 ha, whereas simulated C. melanocephalus covered only 9 ha after one activity season. Normal locomotory activities lead to both exchange of individuals between subpopulations and dispersal out of the habitat. The significance of these phenomena for population stability and for the survival of the species is discussed.
对野外释放的个体铱标记地甲虫的追踪显示，所研究的日行性和夜行性物种都表现出每天随机方向移动距离较短的时期，与每天定向移动且移动距离较长的时期交替出现。这种模式不仅出现在繁殖期，在杂色步甲幼虫和黑首步甲成虫的非繁殖季节也会出现。尽管平均运动活动随温度升高而增加，但个体之间每天存在很大差异，这表明行为不同步。在不利的栖息地，定向移动更频繁且更极端，有时会导致向更有利区域的迁移。大多数放射性甲虫由于辐射影响在7周内死亡，但独立的野外实验和模拟表明所记录的模式是有效的。模拟的生活在1公顷区域内的杂色步甲个体扩散到了49公顷的范围，而模拟的黑首步甲在一个活动季节后仅覆盖了9公顷。正常的运动活动导致亚种群之间个体的交换以及栖息地外的扩散。讨论了这些现象对种群稳定性和物种生存的意义。
