STUDIES ON SOME EGYPTIAN BATS AS POTENTIAL ECOLOGICAL INDICATORS FOR MEASURING CERTAIN CHEMICAL POLLUTANTS

Abstract

Field as well as laboratory studies were carried out on two Egyptian sympatric insectivorous bat species, namely, the Tomb Bat, Taphozous perforatus and the Lesser Mouse-tailed Bat, Rhinopoma hardwickii, inhabiting Saqqara area, Giza Province, Egypt. The study area is located some 17 km south of Giza town and some 40 km southwest of Cairo. Studies were conducted for 24 months extending from January 2012 to December 2013, inclusive, and included both ecological and toxicological studies. The results of the present work are of special interest to wildlife conservationists, agricultural and pest control specialists, public health authorities, and authorities responsible for the control of environmental pollution. A total of 331 individual bats (211 individuals of T. perforatus and 120 individuals of R. hardwickii) was collected throughout the study period. Ecological and population studies included such aspects as age determination of individual bats, sex-ratio, reproductive cycle, age structure, and body weight changes. The determination of relative ages of both bat species depends on measuring the lengths of their forearms. The lengths of digits number three and number five proved to be less useful for arranging individual bats into relative age-groups. However, the relationship between forearm lengths and digital lengths in both bat species are represented by mathematical equations. 254 SUMMARY The study of sex-ratios indicates that males of both bat species slightly outnumbered females in the total sample collected during the study period. These ratios showed noticeable differences between sub-adults and adults of both bat species. The seasonal changes in sex-ratio were more prominent in T. perforatus than in R. harwickii. The reproductive strategy of T. perforatus depends on storing sperms by females after copulation in late autumn months followed by delayed pregnancy, delivery and lactation in late winter, spring, and early summer month. Females thus pass through the following three broad reproductive phases: 1. sexual quiescence (in late summer and early autumn months), 2. insemination and incubation of sperms (in late autumn and early winter months), and 3. delayed pregnancy, delivery and lactation (in late winter, spring, and early summer months). The delivery of young is suggested to occur in late spring. Each pregnant female gives birth to only one young. Reproductively active males