Survival of unweaned and juvenile bank voles under field conditions

With 3 Figs.& 2 Tables] The progress of moults in the annual cycle of the mole was investigated.Material (N = 800) was collected for the most part in one habitat in the grasslands of Krakow.Changes in hair were estimated by the planimetric measuring of pigmented areas on the skin.The spring moults of males and females resemble each other in pattern but differ in time.Unfertilized females moult at the same time as males.The moles from the Tatra Mts.finished the spring moult 10 days later than those of the Krakow region.The summer moult occurs at the same time in all moles.Adult females and young males moult more intensely.Males begin the autumn moult first, but in females the moult proceeds faster.Changes in hair were also ascertained in the winter, especially during the spells of warmer weather.The intensest pigmentation was found in moles from areas with poor edaphic conditions.There were considerable changes in the times of moults of the captive moles.I. INTRODUCTION The seasonal changes of the pelage in the mole Talpa europaea Linnaeus, 1758 have not been studied in the territory of Poland.The purposefulness of taking up such studies is connected, among other things, with the fact that since World War II moles have become an object of interest as fur-bearing animals in Poland, in spite of their being State-protected (Skoczen, 1962).Besides, moulting is an interesting fenological process in mammals, which was given comparatively little attention, especially as regards its dependence upon ecological conditions.Some extensive studies on the seasonal changes of the pelage in small mammals contributed to the knowledge of their evolution (K r y 1 c o v, 1962).In the neighbouring countries, especially in Russia, the seasonal changes of hair in the mole have been investigated by Vjazlinski (1927, after O g n e v, 1928), Folitarek (1932), Baskirov & 2arkov (1934), Kuzjakin (1935), Serianin (1938, cit.after G r i g o r e v, 1956), Pavlinin (1949), Deparma (1951), Borodulina (1953) and G r i g o r e v (1956).* This paper is a part of the series "Studies on the Biology and Ecology of the Mole (Talpa europaea L.) in Poland", [537]') In a lactating female caught in Dr. Jordan's Park on May 6, 1965 the unmoulted area formed 80°/o of the whole skin.