Abstract
Recent studies have emphasized the ecological significance of bats as insect regulators. This recognition has prompted an increased scientific interest in Mormoops megalophylla, a notable neotropical insectivorous bat species. The extant literature on its biology remains limited and substantial knowledge gaps persist, particularly regarding its reproductive cycle. This study sought to examine morphological and histological variations in the reproductive organs of male and female M. megalophylla over the annual cycle to elucidate the stages of its reproductive process. Over the course of the year, five sexually mature individuals of each sex were sampled monthly, culminating in a total of 120 specimens, to document variations in external sexual characters, the testes, epididymides, uterus, and ovaries; all sampled individuals underwent morphological, morphometric, and histological analyses. The findings indicate that M. megalophylla has migratory testes with seasonal spermatogenesis occurring from October to December, a bicornuate uterus, and a single folliculogenic period that is synchronized with spermatogenesis. This suggests a monoestrous, seasonal, and synchronous reproductive pattern. At the population level, copulation occurs between November and December, gestation occurs between December and May, and parturition occurs between late May and early June. The lactation period extended from June to September.