As an adaptation to being nocturnal, Pseudochirulus herbertensis relies heavily on well developed hearing. Close relatives of Herbert River ringtails have such well-developed hearing that they can easily sense the sound of a light switch clicking or mealworms crawling. Very little is known about inter-individual communication in this species, but chemical cues are a likely means of communicating reproductive state, as in most mammals.
Communication Channels: acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
Herbert River ringtail populations currently seem secure. Their dependence on primary rainforest, however, makes them vulnerable to habitat destruction.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
There are no known negative impacts of P. herbertensis.
Herbert River ringtails are important members of the ecosystems in which they live. They may help to attract ecotourism to Australian rainforests they inhabit.
Positive Impacts: ecotourism
Pseudochirulus herbertensis serves as host to up to twelve different types of parasites, the most notable of which are tapeworms and mites. Their herbivory may impact vegetation in the communities in which they live.
Commensal/Parasitic Species:
Herbert River ringtails eat primarily diet leaves that are high in protein content. Specifically, they eat the leaves of pink ash (Alphitonia petriei). Other secondary food sources include brown quandong (Elaeocarpus ruminatus), white basswood (Polyscias murrayi), bumpy satinash (Syzygium cormiflorum), paper-barked satinash (Syzygium alliiligneum), red eungella satinash (Acmena resa), pink bloodwood (Eucalyptus acmenoides), cadaghi (Eucalyptus torelliana), and a vine (Melodinus bacellianus. Ringtails have selenodont teeth which allow them to efficiently grind leaves, promoting bacterial fermentation in the gut. Herbert River rintails have a large caecum and colon specialized for housing the symbiotic bacteria involved in fermentation. Foliage remains in a ringtail's system for a long time relative to that of other animals. Upon completion of fermentation, the contents of the caecum are expelled and then reingested. The nutrient content of this "first cycle" feces is quickly absorbed by the animal's intestine.
Plant Foods: leaves
Other Foods: dung
Primary Diet: herbivore (Folivore ); coprophage
Pseudochirulus herbertensis is found in Australia, in the rainforests of north-eastern Queensland between the Mount Lee area, west of Ingram, and Lamb.
Biogeographic Regions: australian (Native )
Herbert River ringtail possums are found mainly in dense rainforests. They are also occasionally found in tall open forests of flooded gum (Eucalyptus grandis) that border the western edge of the rainforests. They are almost exclusively arboreal, rarely descending to the ground. They live mainly at elevations around 350 meters.
Average elevation: 350 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: rainforest
Herbert River ringtails live an average of 2.9 years in the wild. The maximum known lifespan for P. herbertensis is 6 years.
Range lifespan
Status: wild: 6 (high) years.
Average lifespan
Status: wild: 5 years.
Average lifespan
Status: wild: 2.9 years.
Herbert River ringtails are easily recognized by their black body with white markings on the chest, belly, and upper forearms. Males typically have white surrounding their scrota. While adult ringtails have dark blackish pelage, juveniles are a pale fawn color with longitudinal stripes on their head and upper back. Other differentiating physical features include a pointed "Roman nose" accompanied by pinkish-orange eye shine. Head and body length ranges from 301 mm (in the smallest of females) to 400 mm (in the largest of males). Their prehensile tails range in length from 290-470 mm and taper to a pointed end. Weight ranges from 800-1230 g in females and 810-1530 g in males.
Range mass: 800 to 1530 g.
Range length: 636 to 870 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
One of the only known predation threats to P. herbertensis are carpet snakes (Morelia carinatus) It is reasonable to assume that P. herbertensis is prey to the known predators of its close relative, Pseudocheirus peregrinus. These include powerful owls (Ninox strema) and rufous owls (Ninox rufa).
Known Predators:
This species is probably polygynandrous, but no information on breeding system was found.
Mating System: polygynandrous (promiscuous)
Herbert River ringtails typically breed in early winter and again in the summer. While gestation period is not known, it averages 13 days in many other possum species. Few females carry pouch young into November. The majority of litters range between one and three young, with an average litter size of two. Female ringtails replace deceased young immediately; they can produce two separate litters in the same mating season.
After leaving their mother’s pouch, baby ringtails still feed on milk until as late as February. Although the specific maturation time of Pseudochirulus herbertensis is unknown, for the genera Pseudochirulus, young leave their mother's pouch after 10 weeks. After 10 weeks old, mother possums leave their young in nests while they eat and rest. At 3 to 4 months old, young possums are fully independent and eating adult foods.
Breeding interval: Herbert River ringtails breed twice each year.
Breeding season: There is a major breeding season in early winter and a shorter, second breeding season in summer
Range number of offspring: 1 to 3.
Average gestation period: 13 days.
Range weaning age: 3 to 4 months.
Range time to independence: 3 to 4 months.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Female possums carry their young inside of their pouches for approximately 10 weeks before they are ready to emerge into the world. During this period, the mother provides her babies with milk from teats within her pouch. At the end of the 10 week period, young possums leave their mother's pouch. They stay with the mother, benefiting from her care and milk for 3 to 4 months further.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
The Herbert River ringtail possum (Pseudochirulus herbertensis) is a species of possum found in northeastern Queensland, Australia. It is a dark brown to black species, sometimes with a white belly. The Herbert River ringtail possum was long considered conspecific with the cinereus ringtail possum (P. cinereus), despite the fact that they are very different in appearance. They are, however, the only members of their New Guinea-centred genus found in Australia. The Herbert River ringtail possum is restricted to tropical rainforest from Mount Lee, west of Ingham, to the Lamb Range, west of Cairns.[3]
The Herbert River ringtail's diet mainly consists of leaves with high levels of protein.[4] Some secondary food sources are pink bloodwood, cadaghi, bumpy satinash and white basswood.[4] Pink bloodwood and cadaghi are two different types of Eucalyptus trees.[4] Since the P. herbertensis diet consists of these Eucalyptus trees, ecologist John Kanowski of the Rainforest Cooperative Research Centre at Atherton believes P. herbertensis is one of "seven rare marsupials" threatened by global warming.[5] Kanowski believes that both the Herbert River Ringtail Possum and Daintree River Ringtail Possum are at risk because the increased temperatures from global warming force them and other marsupials to retreat up the mountains, thus “reducing [their] area of favorable habitat.”[6] However, Kanowski is more worried about the increase in Carbon Dioxide (CO2) levels.[6] When CO2 levels increase, it leads to a change in the metabolic process of trees thus "chang[ing] the balance of protein in their leaves" and leading to an increase in production of tannins by the tree.[6] This is problematic because "tannins can potentially inhibit the ability of leaf eating animals to digest protein; [and] at high concentrations, tannins are actually toxic."[6] Therefore, while P. herbertensis may seem secure, their dependency on the rainforest "makes them vulnerable to habitat destruction."[4]
The Herbert River ringtail possum (Pseudochirulus herbertensis) is a species of possum found in northeastern Queensland, Australia. It is a dark brown to black species, sometimes with a white belly. The Herbert River ringtail possum was long considered conspecific with the cinereus ringtail possum (P. cinereus), despite the fact that they are very different in appearance. They are, however, the only members of their New Guinea-centred genus found in Australia. The Herbert River ringtail possum is restricted to tropical rainforest from Mount Lee, west of Ingham, to the Lamb Range, west of Cairns.
