Critically Endangered
Western ringtail possum
Pseudocheirus occidentalis
Western ringtail possum is a mammal in the family Pseudocheiridae (order Diprotodontia) — Pseudocheirus occidentalis, recorded as Critically Endangered.
Appearance
The profile of the black back and rump slopes toward a prehensile tail that tapers to a fine white point. Western ringtail possum has dark grey-brown-black fur with light patches behind the ears and a creamy white, sometimes greyish, colour at the underside of the body that extends to the chest and throat. It differs from the common ringtail possum found on the east of the continent, by lacking any rufous colouration in the fur.
The species has a head and body length of 320–400 mm, a tail length of 300–400 mm, and a weight of 750 to 1350 g.
Range and habitat
The western ringtail is endemic to south-western Western Australia where it is now found in three main areas. The Swan Coastal Plain, Southern Forests around Manjimup, and the South Coast between Walpole and Cheynes Beach. In the Swan Coastal Plain and South Coast, the species favours habitat dominated by Peppermint, as well as Tuart, marri, jarrah, karri, Bullich, Albany blackbutt, Allocasuarina, Banksia, Kunzea, Nuytsia, and Xylomelum. In the Southern Forests, peppermint is generally absent and the western ringtails live in jarrah-dominated eucalypt forests.
However since then, surveys of over 40 public reserves across the south-west have found more than 20,000 western ringtail possums.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
The western ringtail is an arboreal and nocturnal herbivore with a relatively small home range of 0.5-6 ha, dependent on habitat type. It uses tree hollows and builds dreys for shelter in tree canopies, their nest-like drey is an assemblage of shredded bark, twigs and leaves.
Western ringtails are folivorous. Their diet includes leaves, shoots, fruit and flowers of a range of plants, both native and introduced. Ngwayir forage at night through the upper canopy of trees, feeding on young leaves, flowers and fruit, especially in groves of the weeping peppermint Agonis flexuosa.
In crisis
The population has declined by more than 95% since British settlement, due to clearing of habitat, fire and the introduction of the red fox Vulpes vulpes, and is classified as Critically Endangered. The population in most areas has catastrophically declined or become locally extinct, but strongholds remain in the urbanised areas near Busselton and Albany. Within these zones, the threats to western ringtails are complex, interactive and often population-specific.
In 2017, the conservation status of the species was re-assessed by the International Union for Conservation of Nature, and classified as critically endangered, with an estimated population of around 3,400 individuals.
Western ringtail possum is Critically Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Western ringtail possum, Wikidata item Q28044909. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
