Monday, June 4, 2012
Another way to ensure that a pup is born at an optimal time is to delay implantation of the embryo inside the uterus. In seals, fertilization (the meeting of egg and sperm) may take place in April, but the embryo might not implant in the mother's uterus until October. This phenomenon of delayed implantation also occurs in roe deer, armadillos, and badgers. The total gestation period (the time it takes for the pup to develop inside its mother) is 9-15 months, depending on the species. The average active gestation period (the time from implantation to birth) is probably about 3-5 months.