A histological study of Miniopterus schreibersii was carried out in north-eastern New South Wales from April to September 1975. Reproductive tracts were examined from a total of 43 females collected during autumn and winter from three bat colonies in the New England region, Australia.

Copulation, ovulation and fertilization appeared synchronized over a one to two week period amongst all females observed. The conceptus developed to a blastocyst stage prior to commencement of hibernation and remained unattached during at least part of the hibernation period. Unlike populations from the south of France, implantation occurred before hibernation was completed, prior to resumption of regular activity and was not accompanied by an increase in corpus luteum development. The disparity in corpus luteum morphology and activity, suggests that mechanisms of control of delayed implantation in Australian M. schreibersii may differ from those proposed for populations from the south of France.