Virginia opossums are marsupials native to North America, known for their adaptable nature. These solitary, nocturnal animals thrive in diverse environments, from forests to urban backyards, making them a frequent sight across the continent. While often referred to as “possums,” the species found in North America is specifically the Virginia opossum, distinct from the “possums” of Australia. This adaptable creature, roughly the size of a domestic cat, has successfully expanded its range northward over time, inhabiting areas from southern Canada down to northern Costa Rica.
The Possum Breeding Season
The breeding season for Virginia opossums typically begins in late winter or early spring, often starting as early as January or February. This period can extend through the summer months, with most births occurring between February and June. Opossums exhibit a short gestation period, lasting only about 11 to 13 days, which is among the shortest of any North American mammal.
Female opossums can have one to three litters annually, with the exact number often depending on environmental factors like climate and food availability. In warmer regions, it is more common for them to produce two or even three litters. The female’s estrus cycle lasts approximately 28 days. While females can reach sexual maturity as early as six months, and males at eight months, they generally begin breeding around ten months of age.
From Pouch to Independence
Following the brief gestation period, opossum newborns are remarkably underdeveloped, blind, and hairless. They are tiny, about the size of a grain of rice. Immediately after birth, these young must instinctively crawl into the mother’s abdominal pouch, known as a marsupium. Inside the pouch, each surviving young latches onto one of the mother’s 13 teats, which then swells to secure them in place.
The young remain attached to the teat for approximately two months. Their eyes typically open around 55 to 70 days into this stage. As they grow too large to fit for the pouch, usually after about two months, they begin to emerge and cling to the mother’s back. They continue to ride on her back as she forages. Young opossums are weaned around three months of age and achieve full independence when they are about four to five months old.
Encountering Young Possums
Finding a young opossum alone does not always mean it is orphaned or in distress, as mothers sometimes temporarily leave their young. However, if a small opossum is found alone, particularly one that appears injured or if the mother is confirmed to be deceased, intervention may be necessary. Mother opossums do not typically return for babies that have fallen off their backs.
If a young opossum is less than seven to eight inches long (excluding its tail) or weighs under 200 grams, it is likely too young to survive independently. In such cases, avoid direct handling; if handling is unavoidable, wear thick gloves. Do not attempt to give the young opossum any food or water. Instead, place the animal in a warm, dark, and quiet container, such as a box, and immediately contact a local wildlife rehabilitator or animal control for guidance.