BIRD: linking the biodiversity community
The Long-nosed Potoroo (Potorous tridactylus) is a medium sized hopping marsupial which is only found in Southeastern Australia, being confined to Tasmania and the coastal side of the Great Dividing Range on mainland Australia. The family Potoroidae once comprised nine living species in Australia but since European settlement two species have become extinct and a further two species have become extinct on the mainland. Of the five species that once occurred in Victoria only the Long-nosed Potoroo and the Long-footed Potoroo Potorous longipes remain (both endangered in Victoria). The Rufous Bettong Aepyprymnus rufescens, Southern Bettong Bettongia gaimardi and the Brush-tailed Bettong Bettongia penicillata are no longer found in Victoria (Seebeck 1995, VFD 2005). Such a severe depletion of the Potoroidae is an indication that members of this family are highly sensitive to changes in their environment brought about by disturbance to habitats and introduced predators.
Long-nosed Potoroo, captured & released in monitoring program, source: Parks Victoria, Grampians N.P. Distribution of Long-nosed Potoroo in Southwest Victoria, source: VFD (2005) Juvenile Long-nosed Potoroo in care: Andrew Dennis, Parks Victoria, Halls Gap Long-nosed Potoroo taken with remote camera, source: Glenelg Ark -DSE Feral cat at study site – photo taken with remote camera, source: Glenelg Ark -DSE Red Fox at study site – photo taken with remote camera, source: Glenelg Ark -DSE
The Long-nosed Potoroo's fur varies from shades of grey-brown to rufous brown above with pale underside. It has a head and body length about 36 cm and fully furred tail to 23 cm. Its nose is long and tapers to a naked patch of skin. Similar to kangaroos in the family Macropodidae, the Long-nosed Potoroo has large hind legs with long narrow feet and a hopping motion. The Long-nosed Potoroo also has short, muscular forelegs which are used for digging when foraging for food.
Two subspecies of the Long-nosed Potoroo are recognised; Potorous tridactylus tridactylus on mainland Australia and Potorous tridactylus apicalis in Tasmania.
In Victoria, the Long-nosed Potoroo is concentrated at six main geographically isolated locations; East Gippsland, Wilsons Promontory, French Island, Otway Ranges, Lower Glenelg and Grampians. There are four main populations in the South West region; Otway Ranges (Otway Ranges bioregion) and associated foothills (Otway Plain bioregion), Naringal (Warrnambool Plain bioregion), Portland area (Glenelg Plain bioregion) and the Grampians (Greater Grampians bioregion) (VFD 2005).
Habitat & ecology
The Long-nosed Potoroo inhabits coastal heaths and eucalypt forests generally on nutrient-poor sandy or light soils where there is dense groundcover that provides microhabitat for shelter and protection from introduced predators. Whilst dense groundcover is an essential component of Long-nosed Potoroo habitat it does not seem to favour any discrete floristic group, it does however utilise a range of both dense and more open vegetation within a home range (Bennett 1987).
The Long-nosed Potoroo is highly mycophagous (fungus feeding) and more sparsely vegetated areas may be used for foraging where they dig for sporocarps (fruiting bodies) of hypogeal (underground fruiting) fungi. They forage over a range of topographies (from ridge to gully) and aspects (sheltered and exposed) throughout the year. Their foraging patterns are largely influenced by the availability and changing fruit patterns of hypogeous fungi (Claridge et al. 1993, Tory et al.1997, Claridge et al.2000). In Southwest Victoria near Naringal, it was found that hypogeal fungi comprised more than 70% of the diet, particularly during autumn/winter. Invertebrates and plant material were consumed more during spring/summer but hypogeal fungi still comprised at least 25% of the diet (Bennett 1987).
Potoroos have an enlarged forestomach which facilitates microbial fermentation and allows the uptake of nutrients from fungi (Claridge & Cork 1994). Studies in southeastern Australia have recorded up to 60 species of fungus being consumed (Bennett 1987, Claridge et al. 1993) major taxonomic divisions being Basidiomycetes (mushrooms), Ascomycetes (sac fungi) and Zygomycetes (molds).
In situations where forests are undisturbed it has been found that Long-nosed Potoroos consume a larger quantity and diversity of fungi than potoroos in a young regrowth forest indicating differences in the availability of that food resource. Studies to identify factors that influence the distribution, habitat and foraging areas of Potoroos indicate there is a distinct preference for habitats that have remained unburnt for 20 or more years (Claridge et al.2000).
Under normal conditions the Long-nosed Potoroo lives for about 7 years; males are sexually reproductive before reaching their first year, females between one and two years. The adult female Long-nosed Potoroo produces about 2 to a maximum of 3 young per year (Bennett 1987). Females carry a single young in the pouch for about four months duration, they can be found with pouched young at anytime of the year and the reproductive cycle is continuous.
Potoroos are generally considered to be nocturnal, although studies at Ralph Illage sanctuary in Victoria found evidence of diurnal activity where Potoroos were sighted crossing tracks and foraging in clearings throughout the day in a variety of weather conditions (Kirstin 2001). During the day, potoroos usually rest in shallow depressions or nests (squats), which can be located under tussocks, in thickets or among rocks and against logs. The home range area has been measured between 2.0 to 4.0 ha for male potoroos and around 1.4-to 2 ha for females (Bennett 1987, Kirstin 2001). Studies by Kirstin (2001), found the male home range overlapped the ranges of 1-4 females, and ranges of females were overlapped by those of 2-3 males.
The Long-nosed Potoroo is an important part of the forest/bushland ecology, particularly as their diet comprises a high proportion of hypogeous fungi with sporocarps that may enhance the re-establishment of mycorrhizal colonies in logged and/or burned forest sites through dispersal in faeces. The dispersal of mycorrhizal fungi may aid in the recovery of plants regenerating in eucalypt forests (Claridge et al. 1992). The digging mammals such as the Long-nosed Potoroo can also play an important role in mixing leaf litter with soils to aid the aeration of topsoil and breakdown of litter as well as providing substrate for microorganisms, improved water balance and mineral cycles, all which contribute to providing optimal sites for seed germination and seedling establishment (Martin 2003). Claridge et al.(1993) considered the role of the Long-nosed Potoroo to be such an integral part of the forest ecology that it is suggested the potential beneficial role it plays needs to be formally recognised in forest management plans.
Habitat loss: major threats are associated with the clearing of bushland, loss of dense understory and fragmentation of habitats. The inclusion of dense understorey within the home range of the Long-nosed Potoroo is a determining factor for the presence of this species as it provides essential shelter and pockets of habitat diversity. Loss of habitat through frequent and extreme fire events or clearing of vegetation may also impact on the presence and diversity of hypogeal fungi which are a major food source.
Predators: the main predators to Long-nosed Potoroos are introduced animals such as the Feral Cat Felis catus and Red Fox Vulps vulps. Anecdotal observations by Claridge et al. (2000) suggest that where dense ground cover is reduced at a local scale, animals such as the potoroo suffer increased predation by feral predators.
Fragmentation of populations: habitat corridors such as roadside vegetation, streamside vegetation and bushland on farmland were recognised by Bennett (1987) as important areas for the movement and dispersal of Long-nosed Potoroos between patchy and fragmented habitats. Loss of connectivity between habitats results in populations being isolated and more vulnerable to impacts from habitat disturbance.
Fuel reduction burning: Studies on the distribution of the Long-nosed Potoroo by Claridge et al (2000) indicate that Long-nosed Potoroos are more likely to be found in habitats unburned for 20 or more years. This may reflect the time it takes to establish key microhabitats for these species, both in terms of shelter as well as food resources. It is suggested that prescribed burning is being used too frequently in many cases to allow for the creation of suitable habitat for potoroos.
Fuel reduction burning is carried out across the Southwest of Victoria and burning programs may require a closer review in circumstances where potoroos are known to occur to ensure that prescribed burning is carried out with adequate time intervals to allow recovery of habitat and Long-nosed Potoroo populations.
Specific Actions from the DSE Actions for Biodiversity Conservation database
For all areas
- Identify important populations (ie large populations in intact habitat, edge of geographic range populations, genetically distinct populations and populations in atypical habitat)
- Understand habitat requirements and life history.
- Protect habitat from human disturbance.
- Implement survey and monitoring programs to obtain essential demographic data -establish and monitor distribution and abundance of Long-nosed Potoroo.
- Improve public knowledge and understanding of ecological, social and economic issues related to the Long-nosed Potoroo and build community support for recovery.
Lower Glenelg National Park
- In adjoing areas identify threats such timber harvesting; roading and access; grazing; land clearing; plantation establishment; coastal or other development; inappropriate fire regimes; pest (including weeds) management programs.
- Undertake Habitat monitoring.
- Undertake annual surveillance and monitoring of distribution and abundance of Long-nosed Potoroo Populations.
- Bennett, A.W. (1987) Biogeography and conservation of mammals in a fragmented forest environment in South-Western Victoria. A thesis for Doctor of Philosophy, Department of Zoology, University of Melbourne, July 1987. Also; Austral Ecology 14 (3), 375-376. doi:10.1111/j.1442-9993.1989.tb01446.x
- Claridge, A. W., Tanton, M. T., Seebeck, J. H., Cork, S. J. & Cunningham, R. B. (1992) Establishment of ectomycorrhizae on the roots of two species of Eucalyptus from fungal spores contained in the faeces of the long-nosed potoroo (Potorous tridactylus). Austral Ecology 17 (2), 207-217. doi: 10.1111/j.1442-9993.1992.tb00799.x
- Claridge, A.W., Cunningham, R.B., Tanton, M.T. (1993) Foraging patterns of the long-nosed potoroo (Potorous tridactylus) for hypogeal fungi in mixed-species and regrowth eucalypt forest stands in southeastern Australia, Forest Ecology and Management, 61 (1993) 75-90, Elsevier Science Publishers B.V., Amsterdam
- Claridge, A.W., Tanton, M. T., Cunningham, R.B. (1993) Hypogeal Fungi in the Diet of the Long-nosed Potoroo (Potorous tridactylus) in Mixed-species and Regrowth Eucalypt Forest Stands in South-eastern Australia Wildl. Res., 1993, 20, 321-37 link to pdf
- Claridge, A.W. and Cork, S.J.(1994) Nutritional-Value of Hypogeal Fungal Sporocarps for the Long-Nosed Potoroo (Potorous-Tridactylus), a Forest-Dwelling Mycophagous Marsupial Australian Journal of Zoology 42(6) 701 - 710
- Claridge, A.W. and Barry, S.C.(2000) Factors influencing the distribution of medium-sized ground-dwelling mammals in southeastern mainland Australia. Australian Journal of Ecology 25 (6), 676-688. doi: 10.1046/j.1442-9993.2000.01068.x
- Kirstin, I. L. (2001) Spatio-temporal interactions among male and female long-nosed potoroos, Potorous tridactylus (Marsupialia : Macropodoidea): mating system implications Australian Journal of Zoology 49(1) 17 – 26 doi: 10.1071/ZO00077
- Martin, By Greg (2003) The role of small ground-foraging mammals in topsoil health and biodiversity: Implications to management and restoration. Ecological Management & Restoration 4 (2), 114-119. doi.10.1046/j.1442-8903.2003.00145.x
- Seebeck, J.H. (1995) Family Potoroidae x 5 sp., In; Mammals of Victoria, (Ed). Menkhorst, P.W., Oxford University Press, South Melbourne, Australia.
- Tory, M. K., May, T. W., Keane, P. J. & Bennett, A. F. (1997) Mycophagy in small mammals: A comparison of the occurrence and diversity of hypogeal fungi in the diet of the long-nosed potoroo Potorous tridactylus and the bush rat Rattus fuscipes from southwestern Victoria, Australia. Austral Ecology 22 (4), 460-470. doi: 10.1111/j.1442-9993.1997.tb00697.x
- VFD (2005) Victorian Fauna database, Department of Sustainability & Environment, Victoria.
Glenelg Ark is a joint initiative and partnership approach from the Department of Sustainability and Environment, Department of Primary Industries and Parks Victoria working closely with the Glenelg region community to increase populations of native wildlife (eg. Long-nosed Potoroo) by substantially reducing populations of the introduced Red Fox Vulpes vulpes. The program also involves monitoring the populations of species such as the Long-nosed Potoroo to see how they respond to fox control efforts. One of the initiatives is the use of remotely operated cameras to record wildlife movement at certain sites.
- link to DSE - Glenelg Ark information
- link to DSE - Major achievement in fox control Portland & Horsham Forest Management area
- Threatened species A-Z
- Current projects for threatened species & their habitats
- Record sightings
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