PATTERNS OF COOCCURRENCE AMONG ARBOREAL MARSUPIALS IN THE FORESTS OF CENTRAL VICTORIA, SOUTHEASTERN AUSTRALIA

Patterns of co-occurrence were examined among the suite of species of arboreal marsupials that inhabit the montane ash forests of the Centra l Highlands of Victoria, southeastern Australia. The data used in our analyses were counts of different species of arboreal marsupials deriv ed from stagwatching surveys of 152 sites throughout the Central Highl ands region. Our work investigated both the number of species that ten d to occur together, as well as identity of the taxa in such associati ons. A total of eight different species of arboreal marsupials were re corded from field surveys of montane ash forests: Leadbeater's Possum (Gymnobelideus leadbeateri), Sugar Glider (Petaurus breviceps), Yellow -bellied Glider (Petaurus australis), Greater Glider (Petauroides vola ns), Mountain Brushtail Possum (Trichosurus caninus), Feathertail Glid er (Acrobates pygmaeus), Common Ringtail Possum (Pseudocheirus peregri nus), and Eastern Pygmy Possum (Cercartetus nanus). Large assemblages of taxa were rare and no sites supported the full array of species of arboreal marsupials-the maximum number of species recorded on a given 3 ha site was five. The results of our analyses indicated that if any one species of arboreal marsupials was present at a site, then on aver age 1.5 other taxa will co-inhabit that site. The exception was the Co mmon Ringtail Possum. When this species was detected, few other arbore al marsupial taxa tended to be recorded with it. Principal Go-ordinate s Analysis showed that although combinations of animals comprised of e ither Mountain Brushtail Possum, Leadbeater's Possum, or Greater Glide r were often recorded, there were no strong patterns in the identities of co-occurring taxa. This finding, together with the result that mos t taxa in these forests typically co-occurred with one or two other sp ecies, indicates that none of the arboreal marsupials inhabiting the m ontane ash forests of the Central Highlands of Victoria would be a goo d surrogate for (or 'indicator' of), the presence of the suite of othe r species in the assemblage.