Seasonal variation in gonadal steroids of males and females in the Cape mole-rat (Georychus capensis): The potential for opportunistic breeding

Abstract

Urinary testosterone concentrations in males and urinary progesterone and oestradiol concentrations in females were measured in the Cape mole-rat (Georychus capensis) and compared for the summer and winter periods. The Cape mole-rat breeds  seasonally, with sexual activity and subsequent pregnancy recorded during the winter months in the southern hemisphere.  Despite the fact that it has a distinct breeding season, seasonal differences in urinary hormone concentrations of both male and female Cape mole-rats were not statistically significant. This finding supports the notion the Cape mole-rat may have the  opportunity to operate as an opportunistic breeder if fortuitous  environmental conditions arise, such as unseasonal rainfall,  occurring at these normally non-favourable times of the year.

Key words: Cape mole-rat, progesterone, testosterone, oestrogen, seasonal breeding.