Honey Possum - Reproduction

Reproduction

Breeding depends on the availability of nectar and can occur at any time of the year. Females are promiscuous, mating with a large number of males. Competition has led to the males having the largest testes relative to their body weight for any known mammal, being 4.2 percent. Their sperm is also the largest in the mammal world, measuring 0.36mm. Gestation lasts for 28 days, 2-3-4 young being produced. At birth they are the smallest of any mammal, weighing 0.005g. Nurturing and development within the pouch lasts for about 60 days, after which they emerge covered in fur and with open eyes, weighing some 2.5g. As soon as they emerge, they are often left in a sheltered area (such as a hollow in a tree) while the mother searches for food for herself, but within days they learn to grab hold of the mother's back and travel with her. However, their weight soon becomes too much, and they will stop feeding off milk at around eleven weeks, and start to make their own homes shortly after this. As is common in marsupials, a second litter is often born when the pouch is vacated by the first, fertilised embryos being stopped from developing - see diapause.

Most of the time, honey possums will stick to separate territories of about one hectare (2.5 acres), outside of the breeding season. They live in small groups of no more than ten, which results in them engaging in combat with one another only rarely. During the breeding season, females will move into smaller areas with their young, which they will defend fiercely, especially from any males.