The Tasmanian devil (Sarcophilus harrisii) is a distinctive carnivorous marsupial found exclusively on the island of Tasmania. Roughly the size of a small dog, it is known for its stocky build, black fur, and powerful bite. Following the extinction of the thylacine in 1936, it became the world’s largest carnivorous marsupial and plays an important role in its ecosystem.
Addressing the Query
Tasmanian devils do not typically eat their babies; infanticide is not a common behavior for females. However, larger, predatory devils, particularly males, might consume young if encountered; young devils have adapted climbing behaviors possibly to escape this threat.
The misconception may stem from the fierce competition among joeys immediately after birth. A female devil can give birth to 20 to 30 tiny, underdeveloped young, each weighing around 0.20 grams. Despite this large litter, the mother only has four nipples in her pouch.
This creates a literal race for survival, where only the first four joeys to attach to a nipple will survive and develop within the pouch. The remaining newborns, unable to secure a feeding spot, perish, and the mother may consume them to recycle nutrients. This is driven by limited resources, not a deliberate act of parental predation.
Understanding Devil Parental Care
Tasmanian devil reproduction is a distinct marsupial process. Mating typically occurs in March, with females reaching sexual maturity in their second year. After a gestation period of approximately 21 days, the female gives birth to a large litter of extremely underdeveloped young, often the size of a rice grain. These tiny, blind joeys then instinctively crawl from the birth canal into the mother’s backward-facing pouch.
Once inside the pouch, the surviving joeys firmly attach themselves to one of the four available nipples. They remain in the pouch for about four months, growing rapidly from their jellybean-like size. After about four months, weighing around 200 grams, they are ejected from the pouch and continue development in a den, such as a hollow log, cave, or burrow. The mother continues to care for them, providing milk until they are fully weaned between five and six months of age, becoming independent around nine months.
Factors Affecting Joey Survival
Beyond the initial competition for nipples, several other factors significantly impact the survival of young Tasmanian devils in the wild. Devil Facial Tumour Disease (DFTD), a contagious cancer, is a major threat that has reduced devil populations by 80% or more since the mid-1990s. While DFTD primarily affects adult devils, it indirectly impacts joeys by reducing the number of breeding females and shortening their reproductive lifespan.
Young devils also face predation. Wedge-tailed eagles and large owls can prey on young devils, especially if they are active during the day or become separated from their mothers. Spotted-tailed quolls, another native marsupial carnivore, can also pose a risk to juvenile devils. Habitat loss and disturbance, often due to human activities, can expose den sites, making young devils more vulnerable. Roadkill is a significant cause of mortality for devils of all ages, including newly independent young.