Selection of roost sites by the lesser long-eared bat (Nyctophilus geoffroyi) and Gould`s wattled bat (Chalinolobus gouldii) in south-eastern Australia

Physical characteristics of roost sites used by the lesser long-eared bat Nyctophilus geoffroyi and Gould's wattled bat Chalinolobus gouldii were investigated in a farmland–remnant vegetation mosaic and adjacent forested floodplain in south-eastern Australia. A total of 45 individuals of N. geoffroyi and 27 C. gouldii were fitted with radio-transmitters, resulting in the location of 139 and 89 roosts, respectively. Male N. geoffroyi roosted in trees, fallen and decayed timber and artificial structures. These roosts were low to the ground, mainly under bark and in cracks in timber. Roosts of female N. geoffroyi were located higher above ground, and all within trees. Maternity roosts were predominantly located in large dead trees, approximately twice the diameter of roost trees used by females outside the breeding season. No maternity roosts were found under bark, despite half the roosts used by non-breeding females being located in these situations. Both sexes roosted primarily in dead timber and used cavities where the narrowest dimension of the entrance was 2.5 cm. Most roosts of C. gouldii were in dead spouts on large, live river red gum Eucalyptus camaldulensis trees. Intraspecific differences in roost characteristics were less pronounced for this species. Despite access to the same roosting opportunities, there were marked differences in roost selection between N. geoffroyi and C. gouldii. Both species favoured large diameter trees, but differed significantly for all other measured variables: type of roost structure, condition of roost tree (live or dead), height of roost tree, height of roost, and entrance dimensions. Although these species are among the most widespread bats in Australia and are often considered to be habitat 'generalists', both displayed a high level of discrimination in the roosts used. Clearly, roosting requirements are a complex and important issue in the conservation of even the most common species of bats.

Some morphometric and biochemical features of ready-to-migrate silver and pre-migratory yellow stages of the shortfin eel of south-eastern Australian waters

The mean total length (L_T), mass and age of ready to migrate female silver shortfin eels Anguilla australis from the Hopkins River estuary and the mouth of the Merri River in south-eastern Australia, were 83·2 ± 1·2 cm, 1051 ± 51 g, and 17·2 ± 1·79 years, respectively. The eye index (I_E) of the silver shortfin eels was < 5·2 (mean 7·64 ± 0·29) and differed significantly from that of the yellow shortfin eels collected from two other sites. The I_E increased with L_T (mm) and was related by log I_E= 2·656 log L_T6·925. The per cent moisture, protein and ash content of the liver of silver shortfin eels was significantly lower than in yellow shortfin eels, but lipid content was significantly higher in the former (35·5 ± 2·0%). The mean mass μg mg lipid ‾) of saturates (230·4 ± 2·6 v. 181·7 ±2·6), monoenes (367·4 ± 6·3 v. 290·8 ± 8·9) and PUFA (177·3 ± 5·3 v. 159·7 ± 4·6) in muscle was significantly higher, and the great majority of individual fatty acids was found also in higher quantities in silver shortfin eels. In the liver, the PUFA found in the highest quantity was 22:6n-3, except in shortfin eels from Hopkins River estuary, and the amount of 18:2n-6 in the liver of silver shortfin eels was significantly higher than that in yellow shortfin eels but the reverse was true of 20:4n-6. In both muscle and liver tissues the saturate 16:0 and the monoene 18:ln-9 collectively accounted for >50% of all the fatty acids in the lipid.

Nematode assemblages from Avicennia marina leaf litter in a temperate mangrove forest in south-eastern Australia

Meiofauna from Avicennia marina leaf litter in a temperate mangrove forest was enumerated, and the nematode assemblages compared on the bases of leaf colour (used as a guide to leaf age) and shore horizon where samples were collected. Twenty-one putative nematode species were collected from 48 leaf litter samples. Univariate analyses indicated that neither the colour of the leaf nor the shore horizon significantly affected abundance of nematodes. However, of the four (222) treatment groups, rarefaction curves revealed highest diversity on brown leaves from under the shade of the tree canopy (H'=0.751-0.126 SE, n=17). Species diversity of leaf litter nematodes was lower in this temperate mangrove system than reported from tropical mangrove studies. ANOSIM tests confirmed a significant effect of shore horizon on nematode assemblages. The dominant feeding group among nematodes was non-selective deposit feeders (7/21 species, but 77% of all nematodes). Epigrowth grazers were represented by 8/21 species of nematodes, but only 19% of the total number. Excised leaves became skeletonised by about 15 weeks. Shorter temporal scales of life cycles of nematodes compared with leaf degradation, and the dynamic nature of epibiontic assemblages, probably explain the similar assemblage structure on yellow and brown leaves.

Spatial model for predicting the presence of cinnamon fungus (Phytophthora cinnamomi) in sclerophyll vegetation communities in south-eastern Australia

The pathogen Phytophthora cinnamomi causes extensive 'dieback' of Australian native vegetation. This study investigated the distribution of infection in an area of significant sclerophyll vegetation in Australia. It aimed to determine the relationship of infection to site variables and to develop a predictive model of infection. Site variables recorded at 50 study sites included aspect, slope, altitude, proximity to road and road characteristics, soil profile characteristics and vegetation attributes. Soil and plant tissues were assayed for the presence of the pathogen. A geographical information systyem (GIS) was employed to provide accurate estimations of spatial variables and develop a predictive model for the distribution of P. cinnamomi. The pathogen was isolated from 76% of the study sites. Of the 17 site variables initially investigated during the study a logistic regression model identified only two, elevation and sun-index, as significant in determining the probability of infection. The presence of P. cinnamomi infection was negatively associated with elevation and positively associated with sun-index. The model predicted that up to 74% of the study area (11 875 ha) had a high probability of being affected by P. cinnamomi. However, the present areas of infection were small, providing an opportunity for management to minimize spread into highly susceptible uninvaded areas.

Spawning season, fecundity and proximate composition of the gonads of wild-caught blacklip abalone (Haliotis rubra) from Port Fairy waters, south eastern Australia

This study was based on wild-caught blacklip abalone Haliotis rubra L., from Port Fairy waters, south eastern Australia (142°15′E; 38°21′S), from July  1998 to November 1999, and was initiated to evaluate the spawning season and other aspects of its reproductive biology. The shell length and body weight of female and male abalone sampled ranged from 12.0 to 18.6 and 12 to 15 cm, and 137 to 529 and 148 to 585 g, respectively. The sex ratio did not vary significantly from 1:1 through the year. The gonadosomatic index (GSI) ranged from 3.0% to 8.4% in males, and 2.5% to 14.1% for females, and the highest GSI as well as the highest proportion of mature animals were recorded from September to October. During these months the hepatosomatic index (HSI) was low, and an inverse correlation between GSI and HSI (P < 0.05) was evident. Fecundity of blacklip abalone ranged from 1.09 to 7.5 million eggs for females of 12–14.5 cm in length, and 115–487 g in total body weight, respectively. The lipid content of the female gonad increased significantly from about July to November, and an opposite trend was observed for lipid content of the digestive gland. Seasonal changes in the protein and ash contents of the gonad and/or the digestive gland were not always significant.

DDT and metabolites residues in the southern bent-wing bat (Miniopterus schreibersii bassanii) of south-eastern Australia

The southern bent-wing bat (Miniopterus schreibersii bassanii) is an insectivorous, obligate cave dwelling species found in south-eastern South Australia and western Victoria, Australia. In recent times, the finger of blame for an apparent population decline at Bat Cave, Naracoorte (one of only two known maternity roosts for this species, the other being Starlight Cave, Warrnambool) has been pointed at pesticide use in the region, following the finding of organochlorine and organophosphate insecticide residues in bat guano. This study sampled juvenile southern bent-wing bats from Bat Cave and Starlight Cave, and determined DDT, DDD and DDE concentrations in liver, pectoral muscle, brain and back-depot fat tissues.

Mitochondrial 12S rRNA sequences support the existence of a third species of freshwater blackfish (Percicthyidae: Gadopsis) from south-eastern Australia

Fish of the genus Gadopsis are a distinctive component of the freshwater fish fauna of south-eastern Australia. Gadopsis marmoratus and G. bispinosus are the only two species recognised within the genus, with the former of uncertain taxonomic status, as it is thought to be composed of at least two distinct geographical forms based on morphological and allozyme data. The objective of this study was to investigate DNA sequence divergence in Gadopsis, especially in the western portion of its distribution, using an approximately 400 base pair fragment of the mitochondrial small subunit 12S rRNA gene region in order to reassess the taxonomy of the genus. Individuals from 11 locations were sequenced and confirm that G. marmoratus and G. bispinosus are genetically distinct, and further that the G. marmoratus complex consists of two divergent clades representing the previously identified northern and southern forms. The degree of divergence between the three Gadopsis clades was similar (5–6% nucleotide substitutions), suggesting that they diverged from a common ancestor at approximately the same period in geological time. These results are consistent with previous allozyme studies and highlight the usefulness of mitochondrial DNA data coupled with allozyme information for clarifying taxonomic boundaries in morphologically conservative aquatic organisms.

Habitat use by the hymenosomatid crab Amarinus lacustris (Chilton) in two south-eastern Australian rivers

The hymenosomatid crab Amarinus lacustris is abundant in some south-eastern Australian rivers; however, little is known of its ecology. Patterns of habitat use by crabs in rivers may be affected by seasonal changes in river discharge. This study investigates population characteristics, timing of reproduction and patterns of habitat use by A. lacustris in five riffle and pool habitats from each of the Hopkins and Merri Rivers in south-west Victoria, Australia, sampled over a twelve-month period. Distribution of Amarinus lacustris was similar between the two rivers, but log-linear modelling showed that there was a strong association between crab sex, habitat occupied and time of year because female A. lacustris showed a shift from riffle to pool habitats during March and April, coinciding with the non-gravid period of the year. Male crabs also showed a change in relative occurrence, occurring most often in riffles during winter–spring (July–November) but being equally common in both habitats in summer–autumn (January–May). These patterns are probably the result of the reproductive cycle of A. lacustris, which appears to show both ontogenetic and sex-related changes in habitat use during its life cycle, taking advantage of seasonal fluctuations in flow regime that may assist egg/larval development and dispersal.

Melbourne 2006: marketing south-eastern Australian aboriginal art

The Aboriginal cultural sector is dynamic and highly valuable to the Australian economy, returning an estimated $100 million dollars annually. The majority of Aboriginal artists and art works have been perceived to be in northern Australia— eighty per cent of them are in fact in this region—but Aboriginal artists in south-eastern Australia are emerging as a strong force as they struggle for recognition from commercial and national galleries, curators, art dealers, newspaper critics, and buyers. If marketing is to be effectual, the Aboriginality of the art must be presented in a form that is understood and accepted by the audience. Thus changing public perceptions is crucial to marketing south-eastern Aboriginal art. The primary task of this article is to discuss this marketing priority for Aboriginal art and artists in south-eastern Australia, previously neglected in marketing literature. Specifically, the upcoming Melbourne Commonwealth Games are proposed as an opportunity for intensive marketing of the region’s Aboriginal arts.

The diet of powerful owls (Ninox strenua) and prey availability in a continuum of habitats from disturbed urban fringe to protected forest environments in south-eastern Australia

This study investigates the diet of six breeding pairs of powerful owls in the Yarra Valley Corridor in Victoria, Australia, and compares prey consumption with prey availability. The six sites represent a continuum of habitats, ranging from urban Melbourne, through the urban fringe interface to a more forested landscape. We found that powerful owls in the Yarra Valley Corridor are reliant almost exclusively on arboreal marsupial prey as their preferred diet, with 99% of their overall diet comprising four arboreal marsupial species. These four species (the common ringtail possum, common brushtail possum, sugar glider and greater glider) were also the most abundant species observed while spotlighting; however, their abundance varied along the continuum. There was a strong positive relationship with the presence of these species in the diet and their site-specific availability, indicating that the powerful owl is a generalist hunter, preying on the most available prey at a given site and in a given season. This study suggests that food resources are high in these disturbed urban fringe sites and it is unlikely that food availability in urban environments will limit the potential survival of urban powerful owls.

Exotic grass fuel in south eastern Australia

One potentially serious impact of environmental weed invasion is an alteration to the fuel characteristics and subsequent fire regimes of an area. Considerable global evidence indicates that environmental weed invasion may produce 'new' fuel types, but there is little documented evidence of the impact of invasive exotic species on fuel characteristics and fire regimes in south-eastern Australia. This study on the impact of invasive exotic grasses in southeastern Australia has revealed major changes to fuel characteristics, particularly fuel loads.

Changing perceptions : marketing south eastern Australian aboriginal art

The Aboriginal cultural sector is dynamic and highly valuable to the Australian economy, returning an estimated $100 million dollars annually. The majority of Aboriginal artists and art works have been perceived to be in northern Australia-eighty percent of them are in fact in this region-but Aboriginal artists in South Eastern Australia are emerging as a strong force as they struggle for recognition from commercial and national galleries, curators, art dealers, newspaper critics, and buyers. If marketing is to be effectual, the Aboriginality of the art must be presented in a form that is understood and accepted by the audience. 1 Thus changing public perceptions is crucial to marketing South Eastern Aboriginal art. The primary task of this paper is to discuss this marketing priority for Aboriginal art and artists in South Eastern Australia, previously neglected in marketing literature. Specifically, the upcoming Melbourne Commonwealth Games are proposed as an opportunity for intensive marketing of the region's Aboriginal arts.

Agricultural intensification and loss of matrix habitat over 23 years in the West Wimmera, south-eastern Australia

The global trend toward more intensive forms of agriculture is changing the nature of matrix habitat in agricultural areas. Removal of components of matrix habitat can affect native biota at the paddock and the landscape scale, particularly where intensification occurs over large areas. We identify the loss of paddock trees due to the proliferation of centre pivot irrigation in dryland farming areas as a potentially serious threat to the remnant biota of these areas. We used a region of south-eastern Australia as a case study to quantify land use change from grazing and dryland cropping to centre pivot irrigation over a 23-year period. We also estimated rates of paddock tree loss in 5 representative landscapes within the region over the same period. The total area affected by centre pivots increased from 0 ha in 1980 to nearly 9000 ha by 2005. Pivots were more likely to be established in areas which had originally been plains savannah and woodlands containing buloke (Allocasuarina luehmannii), a food source for an endangered bird. On average, 42% of paddock buloke trees present in 1982 were lost by 2005. In the two landscapes containing several centre pivots, the loss was 54% and 70%. This accelerated loss of important components of matrix habitat is likely to result in species declines and local extinctions. We recommend that measures to alleviate the likely negative impacts of matrix habitat loss on native biota be considered as part of regional planning strategies.