Creating a haven for critically endangered western ringtail possums

By Jennifer McMillan 11 October 2023

Australia has the highest number of possum species in the world, each with its own enchanting qualities. There’s the honey possum that delicately delves into flowers with its brush-tipped tongue in search of a sweet treat. And the elusive mahogany glider that disappeared from the scientific radar for 100 years, only to be rediscovered in 1989. Each species possesses unique characteristics and adaptations, but what unifies all possums is their shared reliance on trees.

Protecting habitat is critical to the survival of these iconic Australian animals. Even more so in Western Australia, where mammal extinction rates are among the highest in the world. One species facing serious threat is the ngwayir, or western ringtail possum, whose population has plummeted by 80 per cent over the last 15 years. Ngwayir is the Aboriginal name for this shy relative of the common brushtail possum that is rarely seen on the ground.

Western ringtails are one of 100 threatened species prioritised for protection by the federal government under the Threatened Species Action Plan 2022-2032. They are also on the International Union for Conservation of Nature’s critically endangered list – a classification given to species that face an extremely high risk of extinction. At present, estimates put the figure of adult possums left in the wild at less than 8,000.

Western ringtails are endemic to the southwest corner of Western Australia, where community members are fighting to keep them safe. GeoCatch, a not-for-profit in the Geographe Bay Catchment area, is leading a volunteer effort to protect possum habitat through education and tree planting. This year marked the group’s fourth consecutive National Tree Day event, with 1,000 native seedlings planted with support from Planet Ark’s Seedling Bank.

A major threat to western ringtails is the loss of large, mature trees that keep them high above the ground. As the trees diminish, possums are forced to make their way to the ground more frequently, leaving them vulnerable to predators. Each year, as many as 200 western ringtails end up in the homes of wildlife carers due to loss of habitat or injury.

The towns of Busselton and Dunsborough on the banks of Geographe Bay serve as a crucial stronghold for one of the last remaining populations of these endangered critters. Through habitat creation and possum-aware behavior – such as planting possum-friendly gardens, installing possum boxes and keeping domestic pets inside at night – the GeoCatch community hopes to bring western ringtails back from the brink of extinction.

Recent research adds even more urgency to their mission. The latest predictions estimate western ringtails will become extinct within the next 20 years if immediate action isn’t taken to safeguard their populations and habitat.

This year, GeoCatch volunteers planted infill canopy trees (Agonis flexuosa) as a food source for western ringtails. These trees also provide materials that possums can use to build their homes. If tree hollows aren’t available, western ringtails rest in self-made spherical nests known as ‘dreys’. These cosy beds are made from grass, bark and other plant material loosely woven together by possums.

The group also planted native understory species (Lepidosperma gladiatum) to provide safe passage between trees and protect possums from the heat. Local western ringtails can rest easy in this new safe haven thanks to the work of this dedicated community group.

This story is part of this year's Tree Talk: Stories from Planet Ark's Seedling Bank.

Jennifer McMillan
Jen worked as a vet nurse while studying environmental science and completing her master's degree in Journalism. She loves bushwalking, storytelling, caring for baby animals, Australian birds and river red gums. Jen works on the National Tree Day campaign and Planet Ark's Seedling Bank.