O. G. Dely szerk.: Vertebrata Hungarica 15. (Budapest, 1974)

Topál, Gy.: Field Observation on Oriental Bats. Sex Ratio and reproduction 83-94. o.

Vertebr. Hung. XV. 1974. Field Observations on Oriental Bats Sex Ratio and Reproduction TOPÁL, György Natural History Museum, Budapest ABSTRACT: The paper deals with field observations on sex ratio and reproduction of 32 and 28 species of bats respectively, collected during author's two journeys to North Vietnam and his thirteen months stay in India. There were studied 11 species in Vietnam and 22 in India, whilst further 4 in both countries. INCTRODUCTION In this paper I report some of my field observations made on bats, during my trips to Vietnam in April-May 1966, November-December 1971 and during my stay in India from November 1966 till December 1967. Both journeys to Vietnam took place between the 23° and 20° northern latitudes. During these excursions 25 species of bats were studied and collected, including data on hiding places, biotopes, activities, reproduction, etc. In India - with the exception of the South - I studied 40 species. Some of the data from the eastern parts of the country compare well with those of others from West India. Present paper treats sex ratio and reproduction. The ratio between sexes depends from the biology of a species at a given locality and the season of year, and is often the indicator of the reproductive phase. We already had such data from India (ABDULALI, 1949, GOPALAKRISHNA, 1949, BROSSÉT, 1962, a, b, etc.), but these types of observations were lacking on bats from Vietnam. I give the results of my observations on these subjects, although they seem to be rather scattered, but they might have some value for future investigations. I give the main localities, each with a number, on a map. In text the same numbers are after the name of locality in parentheses. A detailed description of these places and biotopes wiU be published elsewhere. OBSERVATIONS Pteropidae Rousettus leschenaulti (DESMAREST, 1820) In a population of this species 4 adult males were caught by net along with 10 adult females in the Parvati Cave at Poona(9) on August 5. Apart from these, the sex ratio of 6 juveniles obtained was 1:1. It seems clear that there is no segregation of sexes within adult groups, not even during the period of reproduction.