STUDIES ON ACTIVITY AND HOME RANGE OF PLATEAU ZOKOR

Abstract

This work was carried out at Haibei Research Station of Alpine Meadow Ecosys-tem from 1986 to 1988. Plateau Zokor, a fossorial rodent, ranging in the northwest China, lives underground in all its life. By grazing and digging , the zokor causes great damages in grassland, field and forestland. But so far an effective method to study ecology, behavior, and control of plateau zokor has been lacking. Radiotelemetry has been used in this work. 100 animals were monitored by transmitters for studying on the home range and activity rhythm of the zokor. The mainly results were appro-ached. 1. Zokors are polyphasic in daily rhythm. They are active both in the daytime and at night. Although the zokor lives underground in dark, its activity is obviously in circadian rhythm. In summer and autumn, two peaks of activity appeared during 15:00 to 22:00 (65.3% of a day) and 0:00 to 7:00 (21.6% of a day), respectively. In spring, for the soil thawing in the afternoon, activity of the zokor is concentrical from 12:00 to 22:00 (79.7% of a day). In general, activity of the zokor at night is more than, that in the daytime. 2. Zokors are active throughout the day with activity periods interspersed with rest, a greater part of time stay at nest, for example, 100% of daily time is at nest in winter, 90% of daily time at nest for females at nurse, and 75% of daily time is at nest during spring and autumn. Zokors at nest is not only for sleeping and resting, but for eating, excreting, nest building, body cleaning, giving birth, suckling, ect. 3. Zokors begin to copulate in April. During this time males are especially ecti-ve. Adult male and female are not cohabitants even in reproductive period, the mati-ngs occur at a tunnel cross of the male and female in a short time, after mating, they separate from each other. 4. Activity of the zokor above ground has been found not only in summer , but also in autumn, such phenomenon is often at night. For short of foods, underground in summer, zokors may go to the ground to feed on aboveground vegetation, especially the young. Autumn is the most important season for population dispersion . In this time, most of the males and the young will leave their burrow systems for dispersion on the ground. The distance of dispersion is about 200m and a maximum is over 1km. Such result would tend to increase population dispersion throughout the local habitat and would provide a source for newly available habitat. 5. Zokors are living in solitude. Adult male and female occupy seperate home range. In the population the number of females are more than males. Along with dif-ferent season,the home range is quite variable. For males the home range is in spring in autumn in summer in winter, and for females the home range is in autu-mn in summer in spring in winter. Home range of males is larger than that of females. The male has the largest home range (1625m2) and the longest tunnel(226 m) in mating period. The female has the largest home range ( 574 m2 ) during foods collecting season.