Reproduction in the Female White-Striped Mastiff Bat, Tadarida australis (Gray) (Molossidae)

Abstract

The reproductive cycle of female T, australis is outlined from examination of reproductive organs in situ and from histological techniques on museum specimens collected in Australia, south of latitude 22°S., over the last 88 years. Features of the reproductive tract and ovaries during important repro- ductive phases are described. There is a marked asymmetry of the reproductive organs, only the right ovary and uterine horn being functional. T. australis is monoestrous; there is no indication of marked differences in the timing of reproductive phases between regional populations. A single, deeply embed- ded corpus luteum occupies up to 60% of the ovary and degenerates at about the time of parturition. Apparently, most females, including young of the year, become pregnant each year, and give birth to a single young, usually between mid-December and late January, although occasionally as late as the end of February. Most young are weaned by early May. There is a short anoestrus, which is probably restricted to early lactating females, followed by a relatively long pro-oestrus. Copulation, ovulation and fertilization occur around late August. There is no evidence of hibernation.