关键词: 东方田鼠, 繁殖, 温光条件, 迁移, 洞庭湖区

Abstract: The Yangtse voles (M. fortis) colonize the beach of Dongting lake area (28º13'-29º55'N，111º11'-113º43'E) from early autumn to spring when the water level is low and migrate to farmlands during the flood season (from May to June).The Yangtze voles have a high breeding potential during autumn to spring when they inhabit on the lake beach, but the breeding rate largely declines after they move to farmland. It was found that following the migration the testes of males became smaller，and also the pregnant rate of females declined. This makes the breeding rate of the animal's declines to lowest level in June and Ju1y. Our studies by field observations and laboratory experiments show that the temperature and light cycle in summer in Dongting Lake region depress the breeding of Yangtse voles. This is opposite to the most ofMicrotus species that live at high latitudes (above 35ºN).The physical stress of the animals from migration during the flood reinforces the influence.

Key words: Yangtse voles(Microtus fords), Breeding, Temperature, Stress, Dongting lake