Facultative storage of spermatozoa by the female Geoffroy's horseshoe bat (Rhinolophus clivosus)

Abstract

The winter breeding biology of Rhinolophus clivosus on the Gauteng Highveld, South Africa (25°S), was investigated. In contrast with a previous study in Natal (29°S), spermatozoa were not found to be stored in the uterine lumen and glands, since the spermatozoa were phagocytosed by polymorphonuclear leucocytes in the uterus. Only 25% of the females collected contained spermatozoa in their uterotubal junctions and oviducts, where the spermatozoa were oriented towards the epithelium with their heads parallel to one another, an arrangement that is characteristic of sperm-storage sites. The uteri of 66% of the females were infiltrated by large numbers of polymorphonuclear leucocytes, most probably in response to recent inseminations. The results indicate that only 25% of the females retained spermatozoa in their reproductive tracts for an undetermined length of time, whereas 66% of the females were most likely inseminated but did not store spermatozoa for the duration of the winter (May to August). In contrast with R. clivosus in Natal, females of this species on the Gauteng Highveld do not uniformly store spermatozoa for prolonged periods and sperm storage seems to be the responsibility of the males. This illustrates the divergent geographic variability in the reproduction of this species.