Abstract:
The genus Heliophobius comprises of at least six cryptic, topotypical species in the Heliophobius
argentocinereus species complex. The current study investigated the breeding patterns of a wildcaught
population from Tanzania where the putative species H. emini resides. Individuals were
collected on a monthly basis for an entire calendar year. Assessment of foetus presence, gonadal
histology, reproductive tract morphometrics in combination with gonadal steroid (plasma
progesterone and oestradiol-17β in females and testosterone in males) measurements and field
observations revealed that rainfall is important for the onset of breeding. The results further
confirmed that breeding is limited to a single, yearly reproductive event synchonised to the long
rainfall pattern. The distinct breeding peak in July is associated with an elevation in gonadal
mass, increase in concentrations of reproductive hormones and presence of Graafian follicles
and corpora lutea in the ovaries of females. These reproductive parameters coincided with the
end of the long rainfall period, whereas presence of young in the maternal burrow system
corresponded with the start of the short rainfall of East Africa. These findings confirm
Heliophobius has a single breeding opportunity each year, and this species is therefore
vulnerable to any changes that may impact their climatically attuned breeding patterns.
