A mother possum is only pregnant for 16-18 days before her tiny baby is born.
The baby climbs through her fur and into her pouch where it sucks on to her teat. It stays in the pouch drinking the mother’s milk for 4-5 months. When it is too big for her pouch it rides on its mother’s back until it is 7-9 months old.
A newborn brushtail possum is only 1.5cm long and it weighs about 2 grams. That’s the size of a jellybean!
How did possums get to New Zealand?
Possums have thick, soft fur. In 1837 some of New Zealand’s early settlers decided it would be good to start a fur industry, so they brought Australian possums to New Zealand. These first possums did not survive, but people kept trying. Twenty years later they succeeded. The first possum population to survive was in Southland in 1858.
In 1921 the Government made it illegal to bring any more possums to New Zealand. But by then, possums were already living in 450 different parts of New Zealand. In 1946, possums were officially declared a pest in the New Zealand environment.
By 1950 possums were found in over half of New Zealand, and they kept spreading.
In NZ possums are either black or grey. That’s because most of the possums brought to NZ in the 1800s and 1900s came from Tasmania where they are mostly black. The copper coloured possums that live in Queensland weren’t introduced to NZ because their colour wasn’t as popular in the fur trade.
Fiordland and Northland were the last areas of New Zealand to be free of possums. In the 1960s there were hardly any possums in Northland but in the 1990s – only 30 years later – there were 10-15 million possums living in Northland.
Possums numbers reached their highest point in the 1980s when there were 50-70 million possums in New Zealand. Once possum populations got very high, trappers began to make a good living from hunting them. Throughout the 1970s prices for possum skins were good. In 1981, the best year for trappers, 3.2 million skins were exported.
Trapping, poisoning and shooting has now reduced the possum population. But there are still about 30 million possums in New Zealand today.
What’s wrong with possums?
Possums are a serious pest animal in New Zealand and a threat to our forests and native wildlife. They eat leaves, flowers, leaf buds, fruit, eggs, birds, insects and snails.
People used to think that possums only ate plants. But in 1993 possums were filmed eating the eggs and chicks of endangered kōkako. They have since been filmed eating the eggs, chicks and even adults of many other native birds including kererū, kiwi, harrier hawk, fantail, muttonbird, and tūī. They also eat the nectar and berries that native birds like to eat so that there is less food for the birds.
Possums eat about 21,000 tonnes of leaves and flowers in just one night. That’s a lot of forest disappearing while you sleep.
Possums also eat native weta and giant land snails. One possum can eat 60 giant Powelliphanta snails in a single night.
Possums carry a disease called bovine Tb (tuberculosis) which they spread to cattle. They also eat pasture so there is less food for farm animals. The damage done by possums costs NZ farmers about $35 million every year. The New Zealand Government spends over $110 million per year on possum control.
What’s useful about possums?
Possum fur is soft and warm. Possum skins can be used to make clothing and possum wool is mixed with merino sheep wool to make knitting yarn. Possum meat has been found to have a high quality protein which is rich in healthy omega-3 and omega-6 fatty acids. Some New Zealand companies use possum meat to make healthy pet food for cats and dogs. In the 1980s, possum meat was also exported to Taiwan, Hong Kong and Malaysia for people to eat. In these countries it was considered a special food delicacy and was called ‘kiwi bear’.