Gestation Period and Neonatal Weight of the Hyrax

Abstract

THE literature contains only one record of the gestation period of hyrax, namely, that of Murray¹, which was for Procavia capensis in South Africa. Copulation was observed on April 3 and the nine-year-old female gave birth to a single young on November 21, a gestation period of 7.5 months (232 days), a little longer than a previous estimate of 6–7 months². A recent observation on a Mount Kenya hyrax (Procavia johnstoni mackinderi Thomas) provides confirmatory evidence. A mature female, which had been in captivity in the company of two males for nine months, showed a rise in rectal temperature at the end of March (1963), reaching a peak of 38.9° C on April 6. On April 4 what appeared to be seminal fluid was present at the vulva. The female gave birth to a pair of male young on November 3, giving a gestation period of more than seven months (214 days). This suggests that there is little difference between the gestation periods of P. capensis and P. johnstoni, especially when the possibility of parturition being delayed in Murray's animal, due to it being a very old primipara, is borne in mind. The probability that the two gestation periods are the same is consistent with the anatomical evidence that all Procavia are races of one species³.