The stripe-faced dunnart, a tiny carnivorous marsupial found in Australia, has the shortest gestation period of any mammal at just 11 days. Females and males mature at 4 and 9 months of age, respectively. They breed from July through February.
A maximum of 8 joeys are born per litter, as that is the number of teats present in the female. Around two litters are born per season. The young ones first enter the pouch of the female, after which they exit to enter the nest, where they suckle for about a month before leaving the nest.
Virginia opossum is the only marsupial found in the United States. It has a gestation period of only 12 days. A female gives birth to one to 3 litters a year. About 8 to 9 young ones, the size of honeybees, are born per litter. Upon birth, they enter the female’s pouch to suckle. A female has 13 teats on her.
For about 2 months, the joeys remain latched to her teats and leave the pouch at about 2.5 months. After exiting the pouch, they ride on the back of their mother for another 2 months, during which they learn survival skills before they are ready to live a life on their own. However, the survival rates of these joeys is extremely low. Only 1 in 10 reach reproductive adulthood.
Mouse (Domestic White)
Domestic mice have a gestation period of only about 19 days. About 4 to 12 pups are born per litter but occasionally, as many as 30 offspring can be born in a litter. These mammals have an extremely high reproductive rate, so males can mate with females as soon as a litter is born.
Hence, a female can become pregnant again in only 3 days after giving birth. The pups are born naked, deaf, and blind. By 14 days, they can see, hear, and also have fur on their bodies. By the age of 3 weeks, they look like miniature versions of the adult mice.
Hamsters are a group of rodents with 19 species. They are often kept as pets in homes. The average gestation period of a hamster is 20 days. Hamsters give birth to several litters a year with 1 to 13 pups being born in each litter.
The pups are born blind and hairless. They stay in the nest for about a week after birth and then come out to explore the outside world.
Mouse (Meadow) Mouse
The average gestation period of a meadow mouse, also called meadow vole, is 21 days. The species is found across North America. On average, a litter has 4 to 6 pups but sometimes it can be as high as 11.
The neonates are deaf, blind, and hairless just like domestic mouse pups. Weaning lasts for 12 to 14 days.