Mating post partum and length of gestation in the Mongolian gerbil (Meriones unguiculatus)

Abstract

In gerbils mated post partum gestation was prolonged when 3 or more young were nursed. A well-defined linear, positive relationship existed between the length of gestation and number of young nursed, with an increase of 1·9 days per individual young. No evidence was found for the existence of implantation periods approximating in length to a normal oestrous cycle.