The opossum’s breeding season begins at the end of winter – in this area January and February. While foraging during the night, the male opossum smells a female in heat. Female opossums will accept a male only once during the estrus period. However, if a pregnancy does not result during the 36 hours or so that she is in heat, she will continue to come into estrus in 28 day cycles until breeding is successful.
The opossum gives birth to 16-20 (often more) babies, only 12-13 days after mating – the shortest gestation period of any North American mammal. Newborn opossums are about the size of a grain of rice. They cannot see, but will scramble from their birthplace under their mother’s tail, and wriggle across her hairy belly to the safety of her pouch. Most do not survive the journey, as the youngsters must find a nipple, and there are only 13 nipples. Neonates who do not locate a nipple will perish – each infant opossum must attach itself to one of her nipples.
After just 1 week of suckling, the babies triple their size. In 1 week the birth weight increases ten times. After about 60 to 70 days in the pouch, the youngsters’ eyes finally open, they have some control of their body temperatures, and they have grown to the size of a white-footed mouse, weighing about an ounce. At this time they occasionally release their hold on the nipple. Soon they will venture out of the pouch. When they reach 75 to 85 days of age, they are weaned and seldom go back in the pouch. They will stay with their mother until they are about 3 to 4 months old.
Credit : Wildlife Rescue League
Picture Credit : Google
