At last light, a silhouette detaches itself from the shadows on the roof. It is round and fuzzy, with a tail curled into a comma at the tip. It clambers on to the power line and trundles along until it reaches the trees. Parking its fluffy backside on a branch, it starts on the ripening fruit that will never make it to my kitchen.
My guest is a coppery brushtail possum, the blinged-up tropical cousin of the common brushtail possum so familiar in cities. Although I rarely see it, the possum makes itself known. The heavy footfall shifting between march and gallop. The scrabbling as it squeezes into impossibly small spaces. And the staccato hisses and growls when it runs into a rival. Brushies might tolerate humans in their territories, but they draw the line at other possums.
As cities expand and urban areas join up like colonies of mould in a petri dish, wildlife habitat is declining. But coppery brushtail possums and common ringtail possums survive in parks and gardens and in the green ribbons along riverbanks. Roof spaces and garages are substitutes for tree hollows. Fruit trees, vegetable gardens and bird feeders supplement their natural diet. There are new dangers to face – possums must deal with dogs, cats and traffic – but still they persist.
Harry Saddler, a nature writer based in Melbourne, shared his house with a family of common ringtails. When the old metal grille dislodged from an air vent in the wall, possums found the space to their liking.
“I first noticed them when I saw leaves sticking out of the air vent,” Saddler says. “I could tell the number of possums in residence by the amount of sunlight coming through.”
At one point, two adult and two young possums lived in these cosy lodgings. Only pinpricks of light made it past them.
They are polite house guests. Unlike the boisterous and pugnacious brushtails, ringtails tend to keep to themselves.
While brushtails and ringtails are the most commonly encountered possums in cities, they are not the only species present. Krefft’s gliders and sugar gliders often live in well-vegetated locations. Even where numerous, they can be difficult to spot.
“They’re fast, small and well-camouflaged,” Saddler says.
In the absence of tree hollows, these little possums will adopt alternative accommodation. A nest box project in a Melbourne park was a near instant success.
“Within three weeks of installing nest boxes, gliders had moved in.”
Mammal expert Dr Stephen Jackson of the Australian Museum, also suggests nest boxes as a good way to encourage possums.
“In residential areas, possums live where they can,” Jackson says. “Nest boxes are appreciated. They need to be high enough off the ground and to have the right-sized entrances to avoid predation.
“But also plant trees and shrubs that possums will use for food and which will eventually provide real tree hollows.”
The presence of urban possums can have a positive impact on other wildlife. The powerful owl – Australia’s largest owl and one of its rarest – preys on ringtail possums. The abundance of ringtails in Melbourne and other east coast cities supports a small population of these birds.
“When I was a kid, the powerful owl was an almost mythical bird of wet gullies,” Saddler says. “Now it’s out and about in the suburbs of Australia’s largest cities.”
Of the 30 or so possum species in Australia, only a few live close to us. Even in rural areas, encountering other species is a rarity. They might be around, but most possums conduct their lives in darkness and avoid people.
Jennifer Browne is an enthusiastic birdwatcher and avid gardener. Her property on the Atherton Tablelands in Queensland is planted with native trees that attract wildlife. Green ringtail possums sometimes visit.
With their grey-green fur and quiet demeanour, these possums blend in among the lush vegetation. Seeing them requires luck or determination and often both.
“They are very different from the coppery brushtails,” Browne says. “They stay away from the house. There’s no rampaging across the roof, no brawling on the back deck.
“I feel privileged to have them living so close.”
I feel the same way about the brushtail in my ceiling.
Just before first light, it will retrace its path along the power line, its outline rounder and its movement slower, and then wriggle back under the corrugated iron. I never see the return journey, but I hear the possum making little sounds above my head. They could be snores … or complaints about the noisy neighbour downstairs.
How to build a possum-friendly nest box
Possum nest boxes are widely available ready-made, but local wildlife organisations and government departments offer detailed instructions on building your own, tailored to the species in your area.
Size: Boxes should be deep and roomy with an overhang or baffle to protect the interior from rain. The diameter of the entrance is important: 100-120mm for brushtails, 60-80mm for ringtails and 30-50mm for smaller gliders.
Location: Possum nest boxes should be attached to trees and located in protected spots, away from wind and direct sunlight. Height depends on the species. For brushtails and ringtails, about 3 to 5 metres off the ground is adequate. Sugar gliders and their relatives spend their time in the tree tops so prefer their nest boxes at about 4 to 8 metres from the ground.
