黔西北地区农田黑线姬鼠种群数量动态及繁殖特征变化

Population dynamics and propagation characteristics of Apodemus agrarius in the field of northwest Guizhou Province

对1995-2014年贵州省大方县农田黑线姬鼠种群数量动态及繁殖特征进行分析,结果表明:黑线姬鼠主要分布于稻田区和旱地耕作区,占总鼠数的22.01%,为当地农田害鼠第二优势鼠种。多年平均捕获率为0.75%,一年中在6月出现1个种群数量高峰,平均捕获率为1.18%。种群总性比为0.94,雌、雄个体数量差异不显著,多年平均怀孕率为25.49%,平均胎仔数为5.43只,平均睾丸下降率为81.25%,平均繁殖指数为0.67。不同月份之间种群繁殖特征变化存在明显差异,主要繁殖期为4-9月,一年中在4-5月和8-9月出现2个怀孕高峰,平均怀孕率分别为37.50%-55.88%和42.11%-50.00%,怀孕率变化曲线呈典型的双峰型。

According to the statistical analysis of population dynamics and propagation characteristics of Apodemus agrarius in Dafang County, Guizhou Province from 1995 to 2014, A. agrar/us, the second dominant species in local field, mainly perched in paddy and dry farming area, accounting for 22.01% of all rodents. The average annual capture rate was 0.75%. The population peak appeared in June. The population sex ratio was 0.94, the average capture rate was 1.18%, and the quantities of female and male were insignificantly different. The average pregnancy rate was 25.49%, the average litter size was 5.43, the average testicular descent rate was 81.25% and the average propagation index was 0.67. Meanwhile there was significant difference in population propagation characteristics between different months. The mainly reproductive period was April to September. There were two preg- nancy peaks during April and May and during August and September. The average pregnancy rate was from 37.50% to 55.88% and from 42.11% to 50.00%, respectively. The peaks presented a typical bimodal curve.