The reproductive biology of the Ethiopian hedgehog, Paraechinus aethiopicus, from central Saudi Arabia : the role of rainfall and temperature

Abstract

We set out to test whether the Ethiopian hedgehog, Paraechinus aethiopicus is a seasonal or aseasonal breeder and assess which environmental cues bring about both reproductive recrudescence and its subsequent regression. In this study, the body mass, morphometry of the reproductive tract the histology of the reproductive organs and the hormone concentrations of males and females were studied over 12 consecutive months in a wild population of the Ethiopian hedgehog from central Saudi Arabia. Using these data we investigated the potential proximate environmental cues that may trigger the onset of reproduction. Temperature is important for the initial activation of the males by bringing about an increase in testosterone concentration. In female hedgehogs the first rains trigger the onset of reproductive activation with ovulation. In turn increased temperature brings about the final activation of the males with increased testes size and seminiferous tubule diameter. Pregnancies were first recorded in early spring and summer coinciding with a rise in plasma progesterone concentration that peaked in spring. The Ethiopian hedgehog was found to exhibit marked seasonal reproduction. This study strengthens the findings that changes in rainfall and temperature in the Middle East are crucial cues for the onset of reproduction in small mammals.