Abstract: Objective　To assess the effect of the EP-1 on the population reproduction of the desert hamster Phodopus roborovskii. Methods　Baiting bags containing a mixture of wheat and contraceptive compound EP-1 were placed in the field of Hunshandake Sandland, Xilin Gol League, Inner Mongolia, in late April, 2003. Monthly live-trapping survey were conducted from June to October to investigate the impact of EP-1 on the reproductive parameters and structure of the P. roborovskii population. Results　EP-1 did not influence the sex ratio of the P. roborovskii population during the breeding season. In the baited area, EP-1 resulted in a 70%-80% decline in the proportion of juvenile hamsters, which lasted over 4 months. EP-1 profoundly damaged the uteri of approximately 80% of adult female hamsters within 2 months and such impact lasted more than 5 months. In addition, EP-1 significantly reduced the average litter size, which was 1-3 times smaller in the baited area than in the control area. Conclusion　In Hunshandake Sandland, a single delivery of EP-1 in spring is effective in controlling the population of P. roborovskii during the breeding season. However, the impact of EP-1 on the reproduction of P. roborovskii population declines over time, which may be explained by the dispersal behavior of P. roborovskii.

Key words: Phodopus roborovskii, Population reproduction, Fertility control, Hunshandake Sandland

摘要： 目的　检验EP-1不育剂对浑善达克沙地小毛足鼠种群繁殖的控制效果。方法　2003年4月下旬在内蒙古锡林郭勒盟浑善达克沙地,将配好的EP-1不育剂小麦诱饵装袋进行野外大田投撒实验,并在6－10月采用夹线法进行调查,分析EP-1不育剂对浑善达克沙地小毛足鼠种群繁殖参数与种群结构的作用。结果　在小毛足鼠的繁殖期,EP-1不育剂对小毛足鼠的种群性比无影响,EP-1不育剂会造成小毛足鼠种群幼鼠比例下降70%～80%,持续时间达4个月以上;EP-1不育剂会显著损伤小毛足鼠成年雌鼠的子宫,2个月内的损伤率可达80%,作用持续时间可达5个月以上;此外,不育剂还显著降低了小毛足鼠的胎仔数,投药区的平均胎仔数比对照组下降了1～3倍。结论　在浑善达克沙地,春季一次性投放EP-1不育剂,基本可抑制小毛足鼠种群在整个繁殖季节的繁殖成效。但EP-1不育剂对小毛足鼠的繁殖控制成效,也随着时间的推移逐渐下降,可能与沙地小毛足鼠种群间的扩散迁移习性有关。

关键词: 小毛足鼠, 种群繁殖, 不育控制, 浑善达克沙地