Trichosurus caninus (Ogilby, 1835)

Russell A. Mittermeier & Don E. Wilson, 2015, Phalangeridae, Handbook of the Mammals of the World – Volume 5 Monotremes and Marsupials, Barcelona: Lynx Edicions, pp. 456-497 : 484

3.

Short-eared Brush-tailed Possum

Trichosurus caninus

French: Phalanger canin / German: Hundskusu / Spanish: Cuscus de cola de cepillo de orejas cortas

Other common names: Northern Bobuck

Taxonomy. Phalangista canina Ogilby, 1836 ,

“ beyond the Hunter River , about eighty miles north of Sydney in New South Wales,” Australia.

Until 2002, more southerly populations now classified as T. cunninghami were recognized within T. caninus . Morphological and genetic distinctions between T. caninus and T. cunninghami are real but modest, and the two may be better classified as distinct subspecies. Monotypic.

Distribution. E Australia, from SE Queensland to CE New South Wales, in the ranges and coastal plain along the E coast and including Fraser I. It appears the separation between the Short-eared Brush-tailed Possum and the Mountain Brush-tailed Possum (1. cunningham) lies between Sydney and Newcastle in C New South Wales.

Descriptive notes. Head-body 40-55 cm, tail 34—42 cm; weight 2-5—4-5 kg. The Shorteared Brush-tailed Possum is a medium-sized, robust possum that has dark gray coat; blackish, bushy tapering tail; and small rounded ears. An all-black morph is common. Both sexes are similar in size and appearance. The Short-eared Brush-tailed Possum can be distinguished from the Mountain Brush-tailed Possum by having smaller ears and hindfeet but a longertail.

Habitat. Tall wet sclerophyll forests and warm temperate to subtropical rainforests. Short-eared Brush-tailed Possums prefer areas with an abundance of hollows in the trees.

Food and Feeding. The Short-eared Brush-tailed Possum is typically folivorous but will often eat other food items including buds, fruits, fungi, leaves of mesophyll shrubs, lichens, and occasionally bark. Foliage of silver wattle ( Acacia dealbata , Fabaceae ) appears to be the main food source because it comprises 30-50% of diets depending on location and time of year. Flowers and leaves of mistletoes are also consumed but in small amounts.

Breeding. Female Short-eared Brush-tailed Possums are sexually mature at c.2 years of age but typically do not successfully rear young until their third year. There is a distinct breeding season in March—-May, with only occasional births being recorded outside this period. Only a single young is produced at a time, although not all females reproduce each year. Of those that do reproduce, they can give birth to a second young if the first one dies. Mean estrous period is 26 days, and gestation is estimated at 15-17 days,after which young spend 5-6 months in the pouch before they begin to emerge but continue to suckle from one of the teats for 2-5 months. Young remain in their mother’s home range after weaning until they are 18-36 months of age, with dispersal of females occurring before males. After weaning, male Short-eared Brushtailed Possums live up to c.12 years of age; females can live up to c.17 years of age. Carpet pythons ( Morelia spilota ), Dingoes (Canis lupus dingo), and Spotted-tailed Quolls ( Dasyurus maculatus ) are known predators.

Activity patterns. Short-eared Brush-tailed Possums are typically nocturnal and arboreal, although they can spend considerable time on the ground feeding. During the day, they typically rest within tree hollows that can be located in branches, trunks, or logs, but they can also rest in epiphytes.

Movements, Home range and Social organization. Home range sizes of Short-eared Brush-tailed Possums are 5-2-6-9 ha, with average density of 0-35 ind/ha. Observations from spool-lines attached to Short-eared Brush-tailed Possums showed that they spend the majority of their time on the ground. They also travel into pasture but generally not more than 10 m beyond forest edge. Vocalizations are similar to those in the Common Brush-tailed Possum ( T. vulpecula ). Short-eared Brush-tailed Possums also have similar scent glands on chin, sternum, and cloaca that produce musky smells and appear to be important in communicating information about home ranges, age, and potentially reproductive status. Unlike the Common Brush-tailed Possum in which sternal discharge stains its chest dark brown, discharge of the Short-eared Brush-tailed Possum is clear and does not discolor fur. Occurrence of males and females in traps together, extensively overlapping home ranges, and overlapping den tree use suggests a degree of pairing and possibly social monogamy. Genetic results suggest that twothirds of young are fathered by their mother’s social partner, suggesting that extra-pair mating commonly occurs.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Main conservation threats to Short-eared Brush-tailed Possums include clearing of land for agriculture and forestry in some parts of its distribution.

Bibliography. How (2008), Lindenmayer, Dubach & Viggers (2002), Menkhorst, Denny, Winter & Ellis (2008), Smith & How (1973), Viggers & Lindenmayer (2004).

Figures

1. Common Brush-tailed Possum (Trichosurus vulpecula), 2. Coppery Brush-tailed Possum (Trichosurus johnstonii), 3. Short-eared Brush-tailed Possum (Trichosurus caninus), 4. Mountain Brush-tailed Possum (Trichosurus cunningham), 5. Scaly-tailed Possum (Wyulda squamicaudata), 6. Common Bear Cuscus (Aulurops ursinus), 7. Talaud Bear Cuscus (Aulurops melanotis), 8. Mountain Bear Cuscus (Aulurops furvus), 9. Small Sulawesi Cuscus (Strigocuscus celebensis), 10. Small Sangihe Cuscus (Strigocuscus sangirensis)

Distribution. E Australia, from SE Queensland to CE New South Wales, in the ranges and coastal plain along the E coast and including Fraser I. It appears the separation between the Short-eared Brush-tailed Possum and the Mountain Brush-tailed Possum (1. cunningham) lies between Sydney and Newcastle in C New South Wales.