POPULATION STUDIES OF THE EGYPTIAN FRUIT-BAT, Rousettus aegyptiacus, IN GREATER CAIRO, AND ITS ANTIFERTILITY-BASED MANAGEMENT

Abstract

The present work incorporates both population and laboratory studies on the Egyptian fruit bat, Rousettus aegyptiacus. The purpose of these studies is to control this serious vertebrate pest by the use of alpha-chlorohydrin, which is a male antifertility compound. Monthly bat samples of this bat species were collected from a cave in the Aquarium Grotto Garden in Zamalik, Greater Cairo Area for a period of 13 months (June 2017-June 2018).

Population studies included the determination of individual relative ages, mean age at the onset of sexual maturity, seasonal changes in sex-ratio, reproductive activity cycle, seasonal changes in relative weights of male reproductive organs, seasonal changes in sperm count, population age structure, and monthly changes in body weights. Laboratory studies were conducted to evaluate the efficacy and acceptability of alpha-chlorohydrin water-baits by sexually active male bats.

The dried eye-lens weight proved to be a more suitable and accurate tool for the determination of individual ages, compared with traditional tools used in this respect such as the forearm length, and lengths of digit 3 and digit 5. When compared with these latter measurements, the eye-lenses proved to increase in weight for a longer time of the bat's life span, thus allowing for the classification of bat samples to more relative age-classes.