Extensive range contraction predicted under climate warming for a gliding mammal in north-eastern Australia

We used MaxEnt to model the current distribution of the yellow-bellied glider (Petaurus australis) and to predict the likely shift in the species’ future distribution under climate-warming scenarios in the Wet Tropics (WT) Bioregion in north Queensland and in the South-eastern Queensland (SEQld) Bioregion, which encompasses south-eastern Queensland and north-eastern New South Wales. Bioclimatic layers were used to generate models from 57 independent records in the WT and 428 records in SEQld. The modelled distribution of core habitat under current climate showed a good fit to the data, encompassing 91% and 88% of the records in each area, respectively. Modelling of future warming scenarios suggests that large contractions in distribution could occur in both bioregions. In the WT, 98% of core habitat is predicted to be lost under low warming (1°C increase) and 100% under high warming (2−3°C increase) by 2070. In SEQld, 80% of core habitat is predicted to be lost under low warming and 90% under high warming by 2070. These results suggest that this species is highly vulnerable to climate warming and highlight the importance of focusing conservation efforts at the bioregional scale. There is also a need to identify potential thermal refuges and ensure habitat connectivity.

Use of tall wooden poles by four species of gliding mammal provides further proof of concept for habitat restoration

Tall wooden poles (glide poles) and rope canopy-bridges are frequently installed along new highways in Australia to maintain population connectivity for gliding mammals. Knowledge of the use of these structures is rudimentary. We monitored two pairs of glide poles and a canopy-bridge over three years at Port Macquarie, New South Wales. The sugar glider (Petaurus breviceps) and the squirrel glider (Petaurus norfolcensis) were collectively detected on 12–18% of nights on the pole pairs compared with 1% on the rope-bridge. The feathertail glider (Acrobates frontalis) was detected on 3% of nights on the pole pairs compared with 0.2% on the rope-bridge. The yellow-bellied glider (Petaurus australis) was detected twice on one pole. Our results demonstrate that gliding mammals readily use glide poles. Further research is needed to resolve whether glide poles can mitigate the barrier effect of the road canopy gap.

Characteristics of the den trees of the yellow-bellied glider in western Victoria

Effective management of tree-hollow-dependent wildlife is enhanced by detailed knowledge of the trees used for shelter and breeding. We describe the characteristics of 52 den trees and hollows (cavities) used by the yellow-bellied glider (Petaurus australis) in the south-west of its geographic range. We compared the following attributes of den trees to reference trees: tree height, diameter at breast height, hollow entrance height, hollow entrance diameter, cavity diameter, cavity depth, cavity roof height and cavity wall thickness. Dens and reference trees showed a highly significant multivariate difference (P<0.001), with these variables explaining 64% of the variance. Univariate analyses revealed that hollow entrance height was significantly different between den trees (9.0±0.5m) and reference trees (5.5±0.3m). While not significant, den trees tended to have narrower hollow entrances, deeper cavities and thinner walls than reference trees; cavities used by yellow-bellied gliders, on average, measured 36.8cm deep and 18.0cm in diameter, and had entrances 10.6cm in diameter. These observations should assist forest management for this species.

Selection of sap feed trees by yellow-bellied gliders (Petaurus australis) in north-eastern Queensland, Australia – implications for site-specific habitat management

Knowledge of site-specific ecological factors affecting a species’ resource selection is essential to assist in habitat management for a species’ conservation, particularly for species with narrow resource width. This study aimed to assess whether microhabitat variables affect the selection of Eucalyptus resinifera sap feed trees by yellow-bellied gliders (Petaurus australis) in north-eastern Australia. Microhabitat variables were measured in a simplified way around glider-selected and -non-selected Eucalyptus resinifera trees. Canopy cover and percentage of burnt trunk below breast height were identified as influential on feed tree selection, with feed trees showing a higher percentage of burnt trunk and a lower surrounding canopy cover. While the direct effect of fire on a potential feed tree remains to be clarified, fire may affect the structural composition of vegetation leading to lower surrounding canopy cover around potential feed trees. Thus, any forest management, such as logging and grazing should be practiced with great caution since they affect structural features of the vegetation that may contribute to the selection of feed trees by this species and may also affect its alternative food resources.

Population monitoring of a threatened gliding mammal in subtropical Australia

Population monitoring is fundamental to the conservation of threatened species. This study aimed to develop an effective approach for long-term monitoring of the yellow-bellied glider (Petaurus australis) in north-east New South Wales. We conducted repeat surveys to account for imperfect detection and used counts in abundance modelling to produce indices of abundance. We used simulations to explore refinements to our study design. Surveys over three consecutive years produced 195 detections with >95% of detections by call. The probability of detection varied across years and survey occasions, ranging from 0.22 to 0.71. Abundance estimates were remarkably constant across years, ranging from 2.3 ± 0.5 to 2.4 ± 0.6 individuals per site. Occupancy estimates were also constant across years (0.90–0.91). Simulations were run to investigate the influence of the number of surveys (2 or 3) and the number of survey sites (20, 40 or 50) on the probability of occupancy. The design that reduced bias and provided an adequate improvement to precision was that of three visits to 40 survey sites. This design should be adequate to detect a decline in population abundance. Further studies of this kind are needed to better understand the population dynamics of this species.

Gliding performance in the yellow-bellied glider in low-canopy forest

Knowledge of the gliding performance of gliding mammals is fundamental to understanding how these species have adapted to their environment and is of increasing relevance to their conservation. I describe aspects of the glide performance of the yellow-bellied glider (Petaurus australis) based on 22 glides of 17 individuals within 20–30-m-high open forest in western Victoria. Gliders launched into a glide from a horizontal branch that was, on average, 2.8 m below the top of a tree, 5.2 m out from the main trunk and 18.5 m above the ground. Gliders landed on the trunks of trees 5.8 m above the ground. The mean horizontal glide distance was 25.2 ± 1.5 m (s.e.) (range = 19–45 m), producing a glide ratio (horizontal distance/height dropped) of 2.0 and a glide angle of 27.3°. These values are similar to those reported for other gliding petaurids in low-canopy forest. This knowledge should be used to guide the management of habitat connectivity for yellow-bellied gliders.

Monophyly of marsupial intraerythrocytic apicomplexan parasites from South America and Australia

SUMMARYIntraerythrocytic parasites (Apicomplexa: Sarcocystidae) of the South American mouse opossum (Thylamys elegans) from Chile, South America, and of the yellow-bellied glider (Petaurus australis) from Australia were found to be monophyletic using SSU rDNA and partial LSU rDNA sequences. Phylogenetic reconstruction placed both species within the family Sarcocystidae. These intraerythrocytic parasites of marsupials represent an as yet unnamed genus predicted to have bisporocystic oocysts and tetrazoic sporocysts, which is a characteristic feature of all members of the family Sarcocystidae. These results show that erythrocytic parasites share a common ancestor and suggest co-evolution with their vertebrate host.