Reproductive characteristics of the zokors (Myospalax, Rodentia, Spalacidae) in eastern Russia

Original data on the dates of rutting, the birth of cubs, the dispersal of the young, and the brood size of zokors, Myospalax aspalax and M. armandii in Transbaikalia, and M. psilurus both in Transbaikalia and the Primorsky krai are presented. The available literature data on the reproduction of the members of the subfamily Myospalacinae from China, Russia and Kazakhstan are analysed and compared with data on the Myospalacinae from eastern Russia. The lowest fertility is shown to be characteristic of M. armandii in Transbaikalia and a generally low fertility – of the species from eastern Russia in comparison with M. myospalax distributed in western Siberia. Many features such as a small brood size (from 1.75 in M. armandii to 4.67 in M. myospalax in Kazakhstan), the seasonal spring reproduction once a year, a solitary lifestyle even during the rutting, the prolonged breeding, the dispersal of the young, and the predominance of females among adults are characteristic of all study species of both genera of the family, Myospalax and Eospalax.