Population dynamics and population trends of Meriones gerbils in the northwestern Caspian basin and their connection with atmospheric circulation.

摘要

Gerbils of the genus Meriones dominate among small mammals in arid zones of the northwestern Cas pian basin. Animals of this genus play a significant role not only in the biotic community, but also in the main tenance of the natural focus of plague in the Caspian Sea region. The midday (Meriones meridianus Pallas, 1773) and tamarisk (Meriones tamariscinus Pallas, 1773) gerbils form adjacent and frequently mixed pop ulations in a vast area. At the same time, both species have distinctive ecological characteristics. The midday gerbil is a predominantly psammophilous species that prefers fixed and semifixed pitandmount sands. In contrast, the tamarisk gerbil is one of the most hydro phylous species widespread in relatively mesophytic areas [1, 2]. Indirectly, the variation in the dependence on water supply between these species is characterized by a gradual northward rise in the number of tamarisk gerbils.