Opossums are unique mammals native to the Americas. The Virginia opossum, Didelphis virginiana, is North America’s only marsupial, known for raising its young in a specialized pouch. These adaptable creatures have a rapid and highly specialized reproductive cycle, allowing them to thrive across diverse environments.
Key Breeding Seasons
The breeding period for Virginia opossums spans a significant portion of the year, with exact timing varying by geographic location and climate. In northern areas, breeding typically occurs from February through September. In warmer, southern regions, this period can extend from January to August, or even longer. Females usually reach sexual maturity around six months, and males at approximately eight months, though breeding commonly begins around ten months. Food availability and favorable weather influence the duration of these cycles.
From Birth to Independence
The opossum’s reproductive process begins with an exceptionally short gestation period. After only 11 to 13 days, the shortest of any North American mammal, the female gives birth to undeveloped young. These newborns, often described as “honey bee-sized” or resembling a grain of rice, are blind, hairless, and weigh less than a gram.
Immediately following birth, joeys crawl from the birth canal, navigating through their mother’s fur to reach her abdominal pouch. Once inside, each joey locates and firmly attaches itself to a nipple, which then swells within its mouth, securing it in place. They remain in the pouch for approximately two to two-and-a-half months, opening their eyes around 55 to 70 days of age.
As they grow too large for the pouch, young opossums begin to emerge, often riding on their mother’s back. This “piggyback” phase allows them to learn foraging skills and predator avoidance. Independence is typically achieved when the young are around four to five months old, at which point they are weaned and capable of fending for themselves.
How Many and How Often
Opossums produce many young, with litter sizes ranging from 4 to 25 joeys. The average litter typically consists of 8 to 9 infants. A female opossum has an average of 13 nipples, which often limits the number of joeys that can survive, as each must secure a nipple to thrive.
A female opossum can give birth to multiple litters annually, usually one to three, with two being common. This frequency is influenced by environmental factors such as food availability and climate, with warmer regions supporting more breeding cycles. If a female’s first litter does not survive, she may re-enter estrus and breed again.
What to Do If You Find Young Possums
If you find young opossums, first assess if intervention is necessary. A healthy opossum measuring approximately seven to eight inches or more from its nose to the base of its tail is likely old enough to be independent. In such cases, observe from a distance without interfering.
If a young opossum is visibly injured, sick, or smaller than seven inches from nose to rump, it requires assistance. Avoid direct handling without protective gloves. Place the animal in a quiet, dark container, such as a box, and keep it warm without offering food or water, as inappropriate feeding can cause further harm. Immediately contact a local wildlife rehabilitator or animal control for guidance, as it is often illegal for unlicensed individuals to care for wild animals. If a deceased adult female opossum is found, check her pouch for any surviving young, and if present, transport the entire animal to a rehabilitator.