AGE-SPECIFIC REPRODUCTIVE STRATEGIES AND DELAYED EMBRYONIC-DEVELOPMENT IN AN OLD-WORLD FRUIT BAT, PTENOCHIRUS-JAGORI

Ptenochirus jagori (Megachiroptera, Pteropodidae) is a tropical cynopt erine fruit bat restricted to the Philippine islands. Samples of bats were obtained over 4 years, and reproductive tracts were preserved and examined using standard histological techniques. Reproductive status also was recorded for bats captured, marked, and released. A facultati ve post-implantational delay in embryonic development was detected in young P. jagori females reproducing for the first time. The delay occu rred at the stage of gastrulation and could last up to 5 months. Adult females showed little evidence of a delay in development. With this d elay, young females gave birth only once in their first year and synch ronized parturitions with those of adults. Adult females had a gestati on period of 4 months and gave birth twice a year, once in late March and early April and once in August. Morphology of early development wa s similar to that of other cynopterine fruit bats. The evolution and s ignificance of a post-implantational delay in development are discusse d.