The range of lemuroid ringtail possums is restricted to the northeastern rainforests of Queensland, Australia. Hemibelideus lemuroides are found in an area of only 300,000 hectares in two rainforests in the Atherton Tablelands and Mount Carbine Tablelands areas.

Biogeographic Regions: australian (Native )

Lemuroid ringtail possums are small to medium sized animals, with a body length of 30 to 38 cm and a tail length of 30 to 35 cm. Male weights range from 810 to 1060 g, females from 750 to 1140 g. Covered in long fur, the body is uniformly colored: brownish-gray on the back, head, and shoulders, with a yellowish underbelly. A rare white form of H. lemuroides has been documented and is found in unusually high proportions on Mount Carbine. The tail is covered in the same dark fur, with only the tip being bare. The bare tip acts as a friction pad to allow H. lemuroides to climb and grab objects. The highly prehensile tail also aids in steering when these possums throw themselves from tree to tree in great leaps. Each forelimb ends in 5 freestanding digits with an extended hallux to improve grip. Sharp nails on the end of each digit are long and curved, acting like a grappling hook. On the hindlimbs, the second and third toes are fused, making H. lemuroides syndactylous. The most distinctive feature of lemuroid ringtail possums, and the feature most often used by field researchers to identify them, is the color of their eyeshine. The eyeshine, or the color the tapetum lucidum appears to reflect, is bright yellow. Lemuroid ringtail possums are the only animals in the area to have yellow eyeshine.

Adults and young can only be distinguished by comparing body size and eye markings. Young are slightly smaller, have silvery eyeshine, and their eyes are closer together. However, these features are not easy to distinguish when the animals are high up in the canopy.

Lemuroid ringtail possums are very distinctive because of their odd assortment of possum, lemur, and glider-like features. The similarities between these possums and lemurs are in facial characteristics, including short snouts, large, forward-facing eyes, and small ears. Furthermore, similar to gliders, H. lemuroides have skeletal and musculature adaptations to accommodate a leaping lifestyle. Sometimes said to represent an early morphological stage of gliding, H. lemuroides have a flap of skin along their sides that is about 25 mm wide.

Range mass: 750 to 1140 g.

Range length: 30.5 to 38 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: female larger

• Terrestrial

Lemuroid ringtail possums are strictly arboreal. Their habitat is further limited by both elevation and preference for particular tree types. Favoring the high canopies of the rainforest, they are found above 480 meters and 900 meters on the Atherton and Mount Carbine Tablelands, respectively. Furthermore, lemuroid ringtail possums are found only in mature forests, not secondary or regrowth forests.

Range elevation: 900 (high) m.

Average elevation: 480 m.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: rainforest

Lemuroid ringtail possums forage, on average, 16 m above the ground. They are almost exclusively folivorous, specializing in low fibrous leaves, with little variation. Lemuroid ringtail possums eat leaves only from a handful of tree species, preferring young foliage. Preferred tree species are Queensland maple (Flindersia brayleyana), brown quandong (Elaeocarpus ruminatus), and bollywood (Litsea leefeana). If there are no young leaves to be eaten they take mature leaves from their preferred trees, as opposed to eating young leaves from another species. Lemuroid ringtail possums eat other parts of trees as well, particularly the flower buds from brown bollywood (Litsea leefeana) and the fleshy covering of yellow walnut (Beilschmiedia bancroftii).

Plant Foods: leaves; wood, bark, or stems; seeds, grains, and nuts; flowers

Primary Diet: herbivore (Folivore )

Lemuroid ringtail possums may disperse the seeds of some of the fruits they eat.

Ecosystem Impact: disperses seeds

Carpet pythons (Morelia spilota) and rufous owls (Ninox rufa) are the only known predators of Hemibelideus lemuroides. Both predators hunt these possums in the forest canopy.

Lemuroid ringtail possum families band together in a tight cluster when they sense danger. This may dissuade predators from engaging due to sheer numbers. Also, this allows adults to keep their young safely in the pack's middle.

Known Predators:

• carpet pythons (Morelia spilota)
• rufous owls (Ninox rufa)

Communication among lemuroid ringtail possums is not well understood. When a young possum is separated from its mother, the young cry with a keening squeak. Reports differ when describing the behavior of adults. Some say that adults are silent, while others maintain that adults reply to lost offspring with a haunting howl. There is no record of groups communicating vocally. If an threat is sensed, all lemuroids in the area are alerted without vocalizations. They congregate in a group, back to back, maintaining physical contact with each other.

Both sexes of Hemibelideus lemuroides secrete a cream colored fluid, which they rub over themselves. Secretions, accompanied by a strong musky odor, are stimulated when lemuroids are disturbed or handled. This may be a form of communicating identity, reproductive state, or other factors.

Lemuroid ringtail possums have large, forward facing eyes adapted to night vision. It is assumed that through vision they locate food, predators, and fellow possums.

Communication Channels: visual ; tactile ; acoustic ; chemical

Other Communication Modes: scent marks

Perception Channels: visual ; acoustic

Lemuroid ringtail possums have not been held in captivity, nor have any been recorded long term in the wild. Judging by close relatives monitored in the wild, an average life expectancy might be as long as 12 to 15 years.

Average lifespan

Status: wild: 4.0 years.

Little is known about the mating system of Hemibelideus lemuroides. Adults have a strong, long lasting pair bond. Monogamous couples raise their offspring together, forage for food together, and share a den. The exact duration of the pair bond is unknown, but it lasts well into the period when the offspring finally become autonomous, about 9 months after birth.

Mating System: monogamous

Young are born in early August and crawl into the pouch on the female's underside. The young remains in the pouch until November, drinking milk from the mother. While the mother has two teats in her pouch, only one offspring is reared at a time. After 6 to 7 weeks, the young leave the pouch and ride on the mother’s back for another 6 months, from October to April.

Information about sexual maturity is unknown, but we can look for generalizations among their close relatives. Petauroides volans reach sexual maturity after 2 years, lemuroid ringtail possumss may have a similar pattern.

Breeding interval: Lemuroid ringtail possumss breed once yearly.

Breeding season: Mating probably occurs in mid winter (late June, July).

Range number of offspring: 1 (high) .

Average weaning age: 4 months.

Average time to independence: 6 months.

Average age at sexual or reproductive maturity (female): 2 years.

Average age at sexual or reproductive maturity (male): 2 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); viviparous

Average number of offspring: 1.

Parental investment after birth lasts 9 months. The offspring is carried in the mother's pouch for the first 4 months, receiving food and protection. Young Hemibelideus lemuroides are altricial, unable to provide for themselves. The young suckles milk from its mother until it leaves the pouch. Then both parents are active in caring for their young. Lemuroid ringtail possums are social, and the core unit is the adult parents and their single young. Single-family units are often seen foraging with other family groups. Outside of the family, however, there is no hierarchical social structure.

The offspring follow and learn from both parents for another 5 months before gaining independence. During this time, they rarely intentionally leave their parents' side. Both parents spend considerable amounts of time protecting and teaching the offspring. They often remain in close proximity, even when the young have reached adulthood.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female); post-independence association with parents; extended period of juvenile learning

The status of H. lemuroides is stable, but precarious. Populations currently seem healthy but the habitats that they depend on have so far been spared from extensive logging. Lemuroid ringtail possum populations decreased by 97% in secondary forests compared to primary. This is probably because of their reliance on old trees for dens, their reliance on the leaves of only a few, slow-growing tree species, and their preference for high, continuous forest canopies. Any threat to their primary forest habitats will severely threaten their populations.

CITES: no special status

IUCN Red List of Threatened Species: near threatened

There are no known adverse effects of Hemibelideus lemuroides on humans.

There are no known positive effects of Hemibelideus lemuroides on humans.