Opossums are marsupials native to North America, known for their nocturnal habits. Understanding their early development and maternal care is key to appreciating their life cycle. This article details the stages of development for baby opossums, known as joeys.
Early Life and Maternal Care
Opossums have a short gestation period, lasting only about 11 to 13 days. At birth, the joeys are tiny, often described as being the size of a honeybee or a grain of rice. Despite their underdeveloped state, these newborns instinctively crawl from the birth canal into their mother’s abdominal pouch, called a marsupium. Once inside, each joey must locate and firmly attach itself to one of the mother’s nipples, which then swells to hold them in place.
Joeys remain attached to a nipple within the pouch for approximately two to three months. During this period, they grow rapidly, with their eyes typically opening around 55 to 70 days of age. Around two months old, as they become too large for the pouch, they begin to emerge and cling to their mother’s back. The mother carries her growing litter on her back as she forages, providing protection and transportation.
The Journey to Independence
After emerging from the pouch, young opossums continue to ride on their mother’s back for an additional two to three months. This “piggyback” phase is a period of active learning where they observe and imitate their mother. During this time, they learn essential survival skills such as identifying food sources, navigating their environment, and recognizing potential predators.
Weaning typically begins around three months of age, with joeys gradually transitioning from milk to solid foods. By 4 to 5 months old, young opossums are considered independent. At this stage, they are usually about 7 to 9 inches long from nose to rump, excluding the tail. Once they leave their mother, they do not typically reunite, as mother opossums do not return for joeys that fall off their backs.
When to Help a Young Opossum
If a young opossum is found alone, assessing its size is a primary indicator of whether it needs assistance. An opossum measuring less than 7 inches from nose to rump, not including the tail, is generally too young to survive on its own.
Beyond size, certain signs indicate a young opossum requires immediate help. These include visible injuries such as bleeding, open wounds, or contact with a cat or dog, even without obvious wounds. An opossum that appears cold, wet, covered in fly eggs, or is crying continuously also needs help. If any of these conditions are present, avoid offering food or water and instead contact a licensed wildlife rehabilitator for guidance.