Did you know?
Largely solitary, possums do not form strong pair bonds or social groupings. Adult possums have a relatively long life expectancy compared with similar sized animals - in excess of 9 years for males and 12 years for females. Young possums, however, have a very low survival rate unless food supplies and den sites are in good supply. In one study, more than 70% of female offspring disappeared before their second birthday.
Most female possums breed from age 1 onwards. They usually give birth to one young a year, although they sometimes produce two. Autumn, April through to July, is the peak time for births, but a second offspring may be born in spring if food supplies are adequate. The pregnancy lasts for just 17–18 days, when a tiny (0.2 gram), furless, blind baby is born. The baby possum immediately crawls into its mother’s pouch and attaches itself to a nipple for about 70 days.
Young possums are weaned at 5–8 months, but they remain close to their mother until they are almost a year old.
A good food supply means lots of young. The ability to produce more than one offspring per year, and the enhanced survival of juvenile females when conditions are good, allows possum populations to increase rapidly in newly invaded areas or after populations have been reduced and controls have not been maintained.