Opossums are common in many areas, and identifying their sex can offer insights into their behavior. Several distinct physical characteristics provide reliable clues. This article outlines methods to determine a possum’s sex, focusing on anatomical features and safe observation guidelines.
Identifying Females by Their Pouch
The most definitive characteristic for identifying a female possum is the presence of a marsupial pouch. This specialized anatomical feature, located on the female’s abdomen, is a skin fold that opens towards the tail. The pouch serves as a protective incubator where underdeveloped young, known as joeys, continue their development after birth. Only female possums possess this pouch, which is readily visible, particularly when it contains young.
Inside the pouch, joeys attach themselves to milk-secreting teats, remaining there for several weeks to nurse and grow. The pouch is lined with soft fur and features a small opening that the mother can control, ensuring the safety and security of her offspring.
Observing Genitalia for Sex Determination
Observing external genitalia offers another method for sex determination, particularly for male possums. Male possums possess prominent testicles, which are noticeably large and furry, especially during the breeding season. These testicles are positioned anterior to the penis, a characteristic often described as “pre-penile” in their anatomy. Additionally, male opossums have a bifurcated, or fork-shaped, penis, which is a common trait among marsupials.
Female possums, in contrast, have a single urogenital opening located posterior to where the pouch would be present. Internally, the female reproductive tract is also bifurcated, featuring two lateral vaginas and uteri that open externally through this single orifice. While observing genitalia provides a definitive identification, this method often requires closer proximity, which is not always practical or safe with wild animals.
Other Characteristics and Safe Observation
Beyond primary reproductive features, other less reliable characteristics can offer supplementary clues for sex identification. Male possums tend to be larger and heavier than females, typically weighing between 7 to 13 pounds, while females usually range from 5 to 10 pounds. However, this size difference is not absolute, as factors like age, diet, and geographic location can influence an individual’s size, leading to considerable overlap between the sexes. Males may also exhibit a yellow staining on their chest fur due to secretions from scent glands used for chemical communication.
Behavioral cues can sometimes provide hints, though they are not foolproof. Males may display more territorial behavior, particularly during the mating season, and are known to emit clicking sounds to attract females. Females, especially when caring for young, tend to be highly protective. When observing possums, always maintain a safe distance and never attempt to handle them, as they are wild animals that can bite or scratch if they feel threatened. If an injured or orphaned possum is encountered, contacting a local wildlife rehabilitator is the recommended course of action for their safety and well-being.