Raising Brushtail Possums
Brushtail possums are one of two species which are commonly found in suburbia (the other is the ringtail possum). As such, they can be subject to road trauma, dog attacks and bushfires. Should you come across a dead possum, always check the pouch as there could easily be a baby waiting for Mum to wake up and get his breakfast.
A wildlife refuge centre is the best place for a baby possum. Rearing any young animal is a huge commitment in time and raising a young native animal even more so. With a brushtail, six to nine months may pass before you can return to 'normal' living.
However if, for whatever reason, you take on an orphan brushtail, all care should be geared towards its eventual release back into the wild. Brushtails can form strong bonds to their carer, and they are certainly cuddly and lovable while young, but they do not make good long-term pets. Firstly they are nocturnal and the joys of owning a furry, though uncommon pet, pall about one week after they start gallumping through the house while you're trying to sleep. Secondly they cannot be house-trained. Enough said! Brushtail possums are wild animals and much happier in their natural environment.
You will need to check the legalities of keeping a native animal. Each Australian state has different laws regarding this. You may have to apply for a licence not only to keep a possum but also to release it.
In its native habitat, the brushtail frequents a number of different habitats from open woodlands to desert regions and lush forests. They like a variety of older trees which provide the hollows they need to make nests or 'dreys'. A possum likes to have several dreys. Possums come together to mate but are otherwise solitary although they may share feeding sites. Like the ringtail, they have adapted well to suburbia and are not above nesting in ceilings and eaves of buildings. They can become a nuisance if this happens as they chew the coverings of wires and their urine may penetrate the ceiling.
Like the kangaroo and koala, possums are marsupials. The young (joeys) are born blind and naked. The eyes of a brushtail start to open when the baby is three months old and ten days later, a fine covering of fur develops. At 4 to 5 months, the joey will begin to spend a little time each day on the back of the mother. Another fortnight or so and it will start nibbling food while still drinking milk. They will be weaned by 8 or 9 months of age.
Brushtail are tougher and easier to raise than ringtails. Once they are furred, the main danger period is over and as long as there are no complications, the animal should survive.
Orphan babies are fragile and just being orphaned will leave them stressed and traumatised. Keep them warm and quiet. Don't handle them more than is needed for their care and certainly don't hand them round for others to admire. Time enough for that when they're well and strong.
The most important step is to bring the body temperature up to 30 to 32oC. Don't attempt to feed the baby until he is warm. You will need a substitute pouch such as an old sock or beanie. A sleeve of a jumper can be sewn up and makes a good pouch. Fold a hand-towel in half and sew up two edges to make a liner. Make several of these and change them whenever they become soiled or wet. Hygienic conditions are vital with young native creatures. You will need to lay a piece of towelling or cloth over the top to make sure the joey doesn't vacate his pouch and get cold. A hospital box, foot warmer or heat pad is much the easiest way of keeping the youngster warm. Hot water bottles tend to be too hot to start with but then lose heat rapidly.
A home-made warmer can be constructed by placing a 15 watt globe in a large tin. Punch holes in the top to avoid heat build-up. Wrap the tin in a cloth or towel and place it in the corner of a box.
Once the baby is warm, a transition between mother's milk and a commercial preparation can be concocted by mixing 100ml of boiled water with one teaspoon of glucose. Regularity as regards feeding is most important with native animals. Tiny joeys will need feeding every two to three hours Bold round the clock. After each feed, gently massage the genital area to encourage defecation and urination. The joey would normally be stimulated to pass his excrement by the mother licking the area. Marsupials are lactose intolerant and you will need to buy a commercial dry milk product which is especially formulated for possums. As the baby grows, the composition of the natural mother's milk changes to suit the joey's needs. Wombaroo makes two dry milk products which can be used to feed possums.
Baby native animals are particularly susceptible to infection. Sterilise feed bottles and teats and wash the liners regularly. Prepared milk can be kept in the fridge but discard after 24 hours.
Measure the amount of milk the baby drinks. An unfurred baby should be fed every 2 ½ to 3 hours. For joeys weighing 70 grams, less than 2ml should be given. Once they reach 100 grams, this can be increased to 3ml. Always adjust amounts very gradually. Brushtails need 10 to 20% of their bodyweight in milk which is why it's necessary to weigh them. As they gain weight and get stronger, gradually increase the time between feeds and the amount offered. Make all changes very gradually. It is disappointing to raise a possum successfully for some weeks then have it develop an attack of diarrhoea because its milk quota has been increased too quickly.
Once he weighs 250 grams, he should be encouraged to lap. He might take baby custard or cereals. At five months old (and hopefully about 400 grams) he can be introduced to an indoor cage.
At 500 grams, he should have been weaned onto solids. Possums prefer native vegetation and offering native flowers is probably the easiest way to get him started on vegetation. Soft, nicely scented, new-growth tips of native shrubs and trees are also likely to be appreciated. At this time, he can be introduced to an aviary and left alone for short periods. Give him a hollow log so he can start practising making nests. At 750 grams, he should be permanently in the aviary and by the time he weighs 800 grams human contact should be down to a minimum.
Foliage, flowers, buds and berries can be offered. Suitable varieties include plumbago flowers, lilly-pilly, calliandras, river and forest red gum, grevilleas and callistemons. Bananas, pears and mangoes can be offered and many native animals, kangaroos included, seem to love roses. Do not feed oleanders, azaleas or lantana as these are poisonous to most animals. If you have to collect native vegetation from the roadside be sure to wash it thoroughly to remove pollutants and/or pesticides.
Once female brushtails reach 1.2kg or slightly more, they can be released into the wild. Males need to be 1.4 to 1.6kg. Adults weigh between 2 and 4 ½kg depending on sex and the area they come from. Sexual maturity is reached at 18 to 24 months for males and 14 to 16 months for females. Usually only one baby is born at a time.
The possum will have an easier time establishing itself in the wild if it is not fully grown. Adult males will fight viciously if one encroaches on another's territory. The possum will often show signs of being ready for 'life on the outside'. The scent gland becomes prominent; they will become very territorial and will mark their area incessantly.
For a period before releasing them, place food in the cage in daylight and remove uneaten food each morning. Placing branch ends in tins of water will help keep foliage fresh. If possible, before final relinquishing your possum, place the aviary in the release area. This gives the possum a chance to get used to the sights, smells and sounds of his new habitat. Next, leave the door open so they can come and go at will. Brushtails will often come back to the aviary to sleep at night for a week or so. Place branches on the roof to encourage them to leave the aviary.
Finally brushtails do not make good pets. Have I already said that? If there is some reason why they must be kept in captivity, males should be castrated. Although you will be sad to see them go, it really is best to release possums back into the wild.