New Species
Introduction
One of the most important uses of the Australian Museum's vast collections is for scientific research. Each year a range of both Australian and overseas researchers and students use specimens in the collection as a basis for, or to assist them in their studies. The Mammal section also has a number of research associates who use the collections to a much greater extent, as well as enhancing the collections in a variety of ways such as donating specimens, revising identifications or even describing new species. Below are brief summaries of three recent studies that have identified new species of mammals using specimens now lodged in the Australian Museum mammal type collection. One of these new species is from Australia, another from New Caledonia and the third is from the Solomon Islands.
A new species of Mountain Brushtail Possum (Lindenmayer, Dubach and Viggers 2002)
It is rare these days for new species of possums to be discovered in Australia, the most recent one being the Daintree River Ringtail Possum (Pseudochirulus cinereus) in 1945. However, during a long-term ecological study conducted in the forests of south-eastern New South Wales and Victoria, Dr David Lindemayer and colleagues from the Australian National University found evidence for a new species of Mountain Brushtail Possum.
The Mountain Brushtail Possum, (Trichosurus caninus) occurs in wet sclerophyll and sub-tropical forests of eastern Australia from Victoria to central Queensland and can be distinguished from the more widely known Common Brushtail Possum, (T. vulpecula) by its shorter more rounded ears. For many years now this species has been the subject of detailed ecological studies by D. Lindenmayer. During the course of these studies, distinct differences were noticed in external body measurements between northern and southern populations of T. caninus. This led the team to further investigate the apparent variation by extracting DNA from blood samples obtained during the study and sequencing these in order to examine genetic differences between the various populations.
Trichosurus caninus, now called the Short-eared Possum
The results of both morphological and genetic studies indicated that two species were indeed present, a northern one from New South Wales and Queensland and a southern one from Victoria. The morphological features which distinguish the new, southern species, named T. cunninghamii (Mountain Brushtail Possum), from the existing T. caninus (now called the Short-eared Possum) include longer ears, longer feet and shorter tail. The authors were also able to provide an equation that clearly determines which species a particular animal belongs to based on these measurements.
This study highlights the importance of combined morphological and genetic studies in examining species taxonomy. It also indicates that some 'common, widespread' species may in future be found to consist of several species with more restricted distributions and differing habitat requirements, and this can have important consequences for their long-term conservation.
Reference
- Lindenmayer, D.B., Dubach, J. and Viggers, K. L. (2002). Geographic dimorphism in the Mountain Brushtail Possum (Trichosurus caninus) - the case for a new species. A.J.Zool.
A New Species of Long-eared Bat from New Caledonia (Parnaby 2002a)
In May 1990 staff from the Museum's Ornithology and Herpetology sections were mistnetting for birds along a track in mid elevation rainforest on Mt Koghis near Noumea in New Caledonia. Along with the birds they captured a small (microchiropteran) bat with long ears. A year later the Museum's mammal research scientist trapped another two individuals of what has recently been described as a new species of Long-eared Bat, known only from New Caledonia
Seven species of bats, four megachiropterans (Flying-foxes) and three microchiropterans (insectivorous bats) had been recorded from New Caledonia prior to 1990. There was also a reference in the literature to a specimen of Long-eared Bat, (Nyctophilus timoriensis) from 'Noumea' collected in 1897 and lodged in the Natural History Museum in Paris, however as the species was not recorded again during subsequent surveys, the validity of this locality was in doubt. This early specimen and the three collected nearly a century later by Museum staff (and now in the Australian Museum mammal type collection, have been described as a new species, (Nyctophilus nebulosa) by Research Associate Dr Harry Parnaby (2002).
The New Caledonia Long-eared Bat, (Nyctophilus nebulosa) has affinities with the Australian rather than New Guinea Long-eared Bat species and is most similar to Gould's Long-eared Bat, (Nyctophilus gouldi) from eastern and south-western Australia. Measurements of the skull, teeth and external body features indicate that it is a medium-large sized Nyctophilus that differs from N. gouldi in having relatively shorter ears, darker fur and in having a range of skull and dental characters that often fall midway between N. gouldi and the Northern Long-eared Bat, (N. bifax).
N. nebulosa is currently known only from the fragmented rainforests near to the capital Noumea. Based on its limited distribution and the considerable threats to this particular forest type in New Caledonia, it has been assigned an IUCN listing of vulnerable (Parnaby 2002).
Reference
- Parnaby, H.E. (2002). A new species of Long-eared Bat (Nyctophilus: Vespertilionidae) from New Caledonia. Australian Mammalogy 23: 115-124
A new species of Monkey-faced Bat from the Solomon Islands (Parnaby 2002b)
Monkey-faced Bats (genus Pteralopex) are a distinctive and poorly studied group of flying-foxes known only from the Solomon Islands and Fiji. All have very restricted and declining distributions and most are listed as Critically Endangered by the IUCN. Prior to the Australian Museum survey of the South-west Pacific during the late 1980s and early 1990s only three species of Pteralopex were known in the scientific literature. In 1991 Dr Tim Flannery, then research scientist in the Mammal section, described a fourth species P. pulchra based on a single, but very distinctive bat, caught in May 1990 in montane forest on Guadalanal, Solomon Islands. The following month two other members of the team working on New Georgia Island collected another previously undescribed species of Pteralopex from an old village site surrounded by primary lowland forest.
In a recent review of the genus, Dr Harry Parnaby formally described the New Georgia Monkey-faced Bat, Pteralopex taki based on a series of specimens lodged in the Australian Museum collection (Parnaby 2002b). He found P. taki to be most similar morphologically to P. pulchra although it has shorter, dull brown rather than black fur and has a number of dental and cranial features which distinguish it from other members of the genus. The close relationship between P. pulchra and P. taki is also supported by biochemical studies carried out using tissue samples collected from each species.
Ecological studies during the 1990s found that P. taki depends on lowland primary forest with large old trees, for survival (Fisher and Tasker 1997). According to local people this species once occurred on Kolombangara Island but went extinct there as a result of intensive logging between 1966 - 1980. It seems likely that P. taki will become extinct in the near future unless suitable primary lowland forest is protected from logging and clearing for agriculture. Accordingly, an IUCN listing of Critically Endangered is proposed for P. taki by Parnaby (2002).
References
- Parnaby, H. E. (2002). A taxonomic review of the genus Pteralopex (Chiroptera: Pteropodidae), the Monkey-faced Bats of the South-western Pacific. Australian Mammalogy. 23. 145-162.
- Fisher, D. and Tasker, E. (1997). Natural history of the New Georgia Monkey-faced Bat Pteralopex sp. Nov. from the Solomon Islands. Pacific Conservation Biology 3. 134-142.
Copyright © Australian Museum, 2003
