Reproductive timing and postnatal development of the Geoffroy’s bat Myotis emarginatus (Chiroptera: Vespertilionidae) in a breeding colony in Kerend cave, western Iran

Three species of bats Rhinolophus euryale, R. ferrumequinum and Myotis emarginatus housed Kerend Cave,western Iran. In 2016, data were collected for various purposes including cave occupancy, reproductive phenology, and postnatal growth of M. emarginatus. The first bats colonized the cave in late April and the last individuals left the cavein late July after 95 days of occupancy. In the first week of May, average body mass of pregnant females was 8.31±0.29g, n=5, reaching 10.92±0.54 g, n= 12 in early June. In M. emarginatus, births occurred in with high level of synchrony beginning from June 3 and ending in June 15. Mean length of forearm and body mass of neonates followed alinear pattern of growth until 20 days of age with mean growth rates of 1.17 mm/day and 0.20 g/day, respectively, and thereafter growth rates decreased, however, lactating females gained body mass steadily with time. Length of the total epiphyseal gap of the fourth metacarpal-phalangeal joint showed a linear increase up to 8-10 days followed by a linear decrease until day 40 with a mean rate of 0.08 mm/day. The independent juvenile bats had attained more than 90% of the adult dimensions at the time when they started to regularly leave the cave to forage on their own during the first half of July, when young were 5-6 weeks old.

Keywords:

Birth timing , Myotis emarginatus , reproductive synchrony , Kerend cave