典型草原区布氏田鼠的活动节律及其季节变化

采用标志重捕、染色标记和野外观测法研究典型草原区布氏田鼠野外实验种群,采用4 种活动模式指数(日活动差异指数θ,昼行性指数λ,峰型指数;活动强度指数η)分析田鼠昼夜活动节律及其季节变化。结果表明,布氏田鼠全年12 个月的昼行性指数λ 均高于0.542,为典型的昼行性种类。其活动节律的季节变化主要与环境温度有关:1、2、3、4、11、12 月,气温较低,布氏田鼠的活动模式呈典型的单峰型;5、6、7 月气温较高,为典型的双峰型;而8、9、10 月则属于单双峰过渡类型。田鼠的峰型指数 在冬季最低,夏季最高,与月均气温呈显著的正相关关系(r=0.89,n = 12,P<0.05)。活动强度指数η与气温也存在显著的正相关(r=0.94,n = 12,P < 0.05)。5～9 月,布氏田鼠的活动强度最高,每日活动时间在6 h 以上;冬季布氏田鼠的日活动量骤降,很少外出活动,尤其在1～2 月,布氏田鼠日均地面活动时间不足1min。另外,室内实验表明,布氏田鼠具有在黑暗环境中活动能力,但在野外条件下,夜间活动极少发生。

Seasonal changes of the activity patterns of Brandt's vole (Lasiopodomys brandtii) in the typical steppe in Inner Mongolia

Capture-recapture, hair-dying, and direct sighting techniques were conducted on the field population of Brandt's vole (Lasiopodomys brandtii) in typical steppe in Inner Mongolia. Four activity indices (daily-discrepancy index θ,diurnal-nocturnal index λ,peak-type index, absolute-active index η)were used to analysis the seasonal changes of the activity patterns of voles. Result show that the diurnal-nocturnal index (λ)of voles is higher than 0.542 through out the year which suggest the vole is a typical diurnal animal. The seasonal change of activity patterns is related to the environmental temperature. In January, February, March, April, November, and December, as the environmental temperature is low, the activity patterns of the Brandt's vole exhibit a single-peak feature. On the contrary, in May, June, and July, as the environmental temperature is high, the activity patterns possess a double-peak feature. Furthermore, the activity types of August, September, and October are between the single-peak and double-peak. There is a significant positive correlation between the peak-type index and the mean temperature (r= 0.89, n = 12, P < 0,05). Moreover, the absolute-active index η is also apparently correlated with the environmental temperature (r=0. 94, n=12, P< 0.05). From May to September, the daily active time of the Brandt's vole is more than 6 hours. In cold season, however, the daily active time of Brandt's vole is highly reduced. In January and February, the average daily active time on the ground is not more than one minute. Additional lab experiments show that the Brandt's vole is able to be active in dark. However, the night activity is seldom happened in the field population.