Faculty of Applied Ecology, Agricultural Science and Biotechnology, Inland Norway University of Applied Sciences, 2480, Koppang, Norway.
BMC Ecol. 2019 Jan 25;19(1):5. doi: 10.1186/s12898-019-0222-3.
Social behaviour has been linked to hypotheses explaining multiannual population cycles of small rodents. In this paper we aimed to test empirically that the degree of space sharing among adult breeding female voles is higher during the increase phase than in the crash phase, and that the degree of sociality is positively related to population growth rate as suggested by Lambin and Krebs (Oikos 61:126-132, 1991) and Andreassen et al. (Oikos 122:507-515, 2013). We followed 24 natural bank vole Myodes glareolus populations over an area of 113 km by monthly live trapping throughout a complete population cycle of three summers and two winters.
Using spatially explicit capture-recapture models, we modelled the overlap in adult female home ranges and total population growth rate per season. We identified an increase phase before and during the peak density observation and a crash phase following the peak. Female home range overlap were seasonal- and phase-dependent, while population growth rate was associated with season and female home range overlap. High female home range overlap in the increase phase corresponded to a high population growth rate.
We suggest that intrinsic social behaviour plays a key role in the increase phase of vole population cycles, as social behaviour leads to an increased growth rate, whereas extrinsic factors (predation and/or food) initiate the crash phase. Our results are consistent with those of other studies in a variety of small rodent species.
社会行为与解释小型啮齿动物多年种群周期的假说有关。在本文中，我们旨在通过实证检验以下假设：在增加阶段，成年繁殖雌性田鼠的空间共享程度高于崩溃阶段，并且社会性程度与 Lambin 和 Krebs（Oikos 61:126-132, 1991）和 Andreassen 等人提出的种群增长率呈正相关。我们通过每月进行活体诱捕，在一个完整的三个夏季和两个冬季的种群周期中，对 113 公里范围内的 24 个天然田鼠 Myodes glareolus 种群进行了跟踪。
我们使用空间显式捕获-再捕获模型，对成年雌性家域重叠和每个季节的总种群增长率进行建模。我们确定了在高峰期观察之前和期间的增加阶段以及随后的崩溃阶段。雌性家域重叠与季节和阶段有关，而种群增长率与季节和雌性家域重叠有关。增加阶段雌性家域重叠高对应于高种群增长率。
我们认为内在的社会行为在田鼠种群周期的增加阶段起着关键作用，因为社会行为导致增长率提高，而外在因素（捕食和/或食物）引发崩溃阶段。我们的结果与其他各种小型啮齿动物物种的研究结果一致。
