Seasonal Changes in Weight and Reproductive Activity of Suncus murinus in West Bengal, India

A study of seasonal reproductive activity in the house shrew, Suncus murinus, was carried out from December 1962 through September 1963 in Calcutta, West Rengal, India. Data from this study are compared to data reported from Malaya and Guam. Average weight for male Suncus in Calcutta was 105.6 g and that for females was 67.7 g. These weights are higher than the mode of 55 g for males and 45 g for females reported from Malaya, and still higher than the mean of 30 g for males and 21 g for females reported from Guam. The Calcutta sample had an almost equal sex ratio, while a significantly higher proportion of males was reported from both Malaya and Guam. A high level of reproductive activity was found in both sexes throughout the study period in Calcutta with a slight peak in the pregnancy rate during the spring. Comparisons with data from Malaya and Guam indicate that a peak in pregnancy rate occurs in all three areas following a period of relatively low rainfall. This is in the spring in Calcutta and Guam, and in the fall in Malaya. Average litter size in the Calcutta sample was 3.8, which is somewhat larger than the 2.7 and 2.1 reported from Malaya and Guam, respectively.