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We investigated nest temperatures in nest boxes occupied by single lactating brush-tailed phascogales (n = 8 boxes) and 1–3 adult sugar gliders (n = 7 boxes) when overnight ambient temperature dropped to <5°C. Temperature in the nest decreased or increased rapidly as animals vacated or re-occupied their nests. In the hour following first night-time departure, temperatures in sugar glider nests dropped by 9°C but only by 4°C in phascogale nests. The slower rate in phascogale nests was due to the presence of nestlings. Phascogales returned repeatedly to the nest during the night, resulting in an average 15°C differential above ambient over the night (2200–0500 h). Gliders returned infrequently during the night, resulting in an average nest-ambient differential of 3–5°C. After departure some glider nests tracked ambient to <0°C. The ability of nests to insulate and moderate temperature fluctuations requires further study. Our study highlights that we have incomplete knowledge of many aspects of the nesting ecology of cavity-using Australian mammals. We describe winter temperature variation in nest boxes occupied by brush-tailed phascogales and sugar gliders when overnight temperatures dropped to <5°C. Phascogale mothers returned often during the night, keeping nest and nestlings warm. Gliders returned infrequently to the nest, so some nests tracked ambient to <0°C. [ABSTRACT FROM AUTHOR]

Landscape genetics lacks explicit methods for dealing with the uncertainty in landscape resistance estimation, which is particularly problematic when sample sizes of individuals are small. Unless uncertainty can be quantified, valuable but small data sets may be rendered unusable for conservation purposes. We offer a method to quantify uncertainty in landscape resistance estimates using multimodel inference as an improvement over single model-based inference. We illustrate the approach empirically using co-occurring, woodland-preferring Australian marsupials within a common study area: two arboreal gliders ( Petaurus breviceps, and Petaurus norfolcensis) and one ground-dwelling antechinus ( Antechinus flavipes). First, we use maximum-likelihood and a bootstrap procedure to identify the best-supported isolation-by-resistance model out of 56 models defined by linear and non-linear resistance functions. We then quantify uncertainty in resistance estimates by examining parameter selection probabilities from the bootstrapped data. The selection probabilities provide estimates of uncertainty in the parameters that drive the relationships between landscape features and resistance. We then validate our method for quantifying uncertainty using simulated genetic and landscape data showing that for most parameter combinations it provides sensible estimates of uncertainty. We conclude that small data sets can be informative in landscape genetic analyses provided uncertainty can be explicitly quantified. Being explicit about uncertainty in landscape genetic models will make results more interpretable and useful for conservation decision-making, where dealing with uncertainty is critical. [ABSTRACT FROM AUTHOR]

Tree hollows are a major feature within Australian habitats and an important functional resource for many species in terms of shelter, reproduction, and thermoregulation. Water-filled tree hollows, or phytotelmata, also function as a valuable resource, but their use is only scarcely documented. We used camera trapping to determine which vertebrate species were utilising a known water-holding hollow in dry woodland habitat, and assessed whether antagonistic behaviour, such as hoarding of the resource, was occurring. Camera footage was obtained over a period of three days and nights, and species' use of the hollow analysed. A total of seven vertebrates (one frog, two reptile and four mammal species) were recorded using the hollow, which included diurnal and nocturnal species. Use by the Feathertail Glider was the most frequent compared to other species. The study highlights an ecological significance of water-filled hollows that should be considered in the management of dry woodland habitats, where the availability of these resources may be depleted by land clearing and loss of existing hollow-bearing trees. [ABSTRACT FROM AUTHOR]

Recently proposed ancestral locomotor and morphological ‘stages’ leading to the evolution of primates have emphasized small body size, and a transition from a clawed non-grasping stage, to a clawed, grasping stage with clawless opposable hallux, to a fully-nailed primate with grasping extremities. This evolutionary transition was presumably associated with frequent use of the small branch niche. To model elements of these evolutionary transitions, we investigate how body size, substrate size, substrate orientation and grasping morphology interact to influence quadrupedal kinematics within and between ontogenetic samples of two small-bodied marsupials, one arboreal (Petaurus breviceps) and the other mainly terrestrial (Monodelphis domestica). Longitudinal morphometric and kinematic data were collected from four juvenile P. breviceps (33–75 g) and two juvenile M. domestica (18–95 g) walking across poles of three diameters (2.5, 1.0, and 0.5 cm) and three orientations (horizontal, 30° incline, 30° decline). The two species responded similarly to some substrate conditions, but diverged in response to others. Kinematic divergence between the two species reflects Monodelphis' relatively shorter digits, reduced grasping ability and greater need for stabilizing mechanisms on narrow substrates. At a given relative body size or pole orientation, Monodelphis used higher limb duty factors, more limbs in support per stride, lower limb phases, and in some conditions, faster speeds compared with Petaurus. Interspecific differences were the least distinct on declined poles, highlighting the particular challenge of this substrate condition, even for arboreally adapted species. Small-bodied, arboreal primate ancestors would likely have employed the kinematic mechanisms common to our model taxa, but those with enhanced grasping adaptations would most likely not have required the increased level of stabilizing mechanisms exhibited by Monodelphis. Thus, using these two species as locomotor models has underscored the functional importance of grasping extremities in primate origins, even if ancestral primates were very small in body size. [ABSTRACT FROM AUTHOR]

Forests and woodlands are under continuing pressure from urban and agricultural development. Tree-dependent mammals that rarely venture to the ground are likely to be highly sensitive to forest fragmentation. The Australian squirrel glider (Petaurus norfolcensis) provides an excellent case study to examine genetic (functional) connectivity among populations. It has an extensive range that occurs in a wide band along the east coast. However, its forest and woodland habitat has become greatly reduced in area and is severely fragmented within the southern inland part of the species' range, where it is recognised as threatened. Within central and northern coastal regions, habitat is much more intact and we thus hypothesise that genetic connectivity will be greater in this region than in the south. To test this we employed microsatellite analysis in a molecular population biology approach. Most sampling locations in the highly modified south showed signatures of genetic isolation. In contrast, a high level of genetic connectivity was inferred among most sampled populations in the more intact habitat of the coastal region, with samples collected 1400 km apart having similar genetic cluster membership. Nonetheless, some coastal populations associated with urbanisation and agriculture are genetically isolated, suggesting the historic pattern observed in the south is emerging on the coast. Our study demonstrates that massive landscape changes following European settlement have had substantial impacts on levels of connectivity among squirrel glider populations, as predicted on the basis of the species' ecology. This suggests that landscape planning and management in the south should be focused on restoring habitat connectivity where feasible, while along the coast, existing habitat connectivity must be maintained and recent losses restored. Molecular population biology approaches provide a ready means for identifying fragmentation effects on a species at multiple scales. Such studies are required to examine the generality of our findings for other tree-dependent species. [ABSTRACT FROM AUTHOR]

The article discusses results of a study that investigates the use of den trees and the availability of hollow-bearing trees near Mackay in the tropical north of the range of squirrel glider, Petaurus norfolcensis where information was deficient. The study materials and methods are described, including installation of 56 nest boxes to determine the use of squirrel gliders, with only 20 percent used after 3 years but the use was not influenced by the availability of tree hollows. It showed that den trees were larger than available trees while dead den trees were smaller than live den trees.

The article discusses results of a study that assesses the habitat loss and current threats of the mahogany glider, Petaurus gracilis. The study materials and methods are provided, including the use of regional ecosystem mapping to identify the true extent of habitat loss from clearing and the habitat degradation due to the transition to rainforest. The study showed that the loss of habitat happened mostly on freehold land where it has reduced from 129,435 hectares to 26,852 hectares. It concludes that the remaining habitat must be actively managed to ensure its usefulness to the mahogany glider.

The distribution of the squirrel glider (Petaurus norfolcensis) extends for 3,000 kilometres along the eastern coast of Australia. Human-induced habitat loss and fragmentation is a major factor resulting in the decline in distribution of this species. Records indicate the presence of the squirrel glider on a number of the islands off the coast of southeast Queensland, where the threatening processes of fragmented mainland habitat are reduced or absent. The main aims of this study were to determine the presence of the squirrel glider on southeast Queensland islands, and to estimate the density of these populations to determine whether there is any difference in density between island and mainland populations. Trapping surveys were conducted on Fraser Island, Moreton Island, North Stradbroke Island, Peel Island, South Stradbroke Island, Woogoompah Island and Coomera Island. Surveys were also conducted in three mainland patches. Results of the study confirmed that the squirrel glider exists on five of the seven islands. Density estimates for island populations ranged between 3.01 and 8.48 individuals ha-1 with an average (± s.e.) of 4.94 ± 0.55 individuals ha-1. Island population densities were not signifi cantly different from mainland populations, which had an average density (± s.e.) of 4.12 ± 0.53 individuals ha-1. Overall, the study provided up-to-date records for the squirrel glider on islands in southeast Queensland, as well as new information on population densities in this species. Results highlight the importance of retaining large areas of bushland (>700 ha) on the mainland to ensure the long-term persistence of populations of the squirrel glider. [ABSTRACT FROM AUTHOR]

This article discusses a study which aimed to identify the variation in the home-range size of squirrel gliders or Petaurus norfolcensis at Minnippi Parklands in Queensland and at Tea gardens in New South Wales. The study applied estimation techniques to compare the home-range size of the animals. It used a set of 26 trap points to collect squirrel gliders. The study found differences in the home-range size of the animals. It suggested that the size implies how the animals respond to variation in the quality of their habitats.

Roads and traffic are prominent components of most landscapes throughout the world, and their negative effects on the natural environment can extend for hundreds or thousands of meters beyond the road. These effects include mortality of wildlife due to collisions with vehicles, pollution of soil and air, modification of wildlife behavior in response to noise, creation of barriers to wildlife movement, and establishment of dispersal conduits for some plant and animal species. In southeast Australia, much of the remaining habitat for the squirrel glider, Petaurus norfolcensis, is located in narrow strips of Eucalyptus woodland that is adjacent to roads and streams, as well as in small patches of woodland vegetation that is farther from roads. We evaluated the effect of traffic volume on squirrel gliders by estimating apparent annual survival rates of adults along the Hume Freeway and nearby low-traffic-volume roads. We surveyed populations of squirrel gliders by trapping them over 2.5 years, and combined these data with prior information on apparent survival rates in populations located away from freeways to model the ratio of apparent annual survival rates in both site types. The apparent annual survival rate of adult squirrel gliders living along the Hume Freeway was estimated to be approximately 60% lower than for squirrel gliders living near local roads. The cause of the reduced apparent survival rate may be due to higher rates of mortality and/or higher emigration rates adjacent to the Hume Freeway compared with populations near smaller country roads. Management options for population persistence will be influenced by which of these factors is the primary cause of a reduced apparent survival rate. [ABSTRACT FROM AUTHOR]

Abstract: The glider genus Petaurus comprises a group of arboreal and nocturnal marsupial species from New Guinea and Australia. Molecular data were generated in order to examine phylogenetic relationships among species within the genus and explore the time-scale of diversification and biogeographic history of the genus in Australia and New Guinea. All known species and subspecies of Petaurus (with the exception of P. biacensis) were sequenced for two mitochondrial genes (ND2 and ND4) and one nuclear marker (omega-globin gene). Phylogenetic analyses confirmed the monophyly of the genus relative to other petaurids and showed a sister relationship of P. australis to the rest of Petaurus. The analyses revealed that currently recognised species of Petaurus formed distinct mitochondrial DNA (mtDNA) clades. Considerable mtDNA diversity and seven distinct clades were identified within the species P. breviceps, with the distribution of each clade showing no correspondence with the distributional limits of known subspecies. Molecular dating analyses using BEAST suggested an early to mid-Miocene origin (18–24mya) for the genus. Ancestral area reconstructions, using BayesTraits, did not resolve the location for the centre of origin of Petaurus, but provided evidence for at least one dispersal event from New Guinea to Australia that led to the evolution of extant Australian populations of P. breviceps, P. norfolcensis and P. gracilis. The timing of this dispersal event appears to pre-date the Pleistocene, adding to the growing number of studies that suggest faunal connections occurred between Australia and New Guinea in the Late Miocene to Pliocene period. [Copyright &y& Elsevier]

Abstract: This study describes the first attempt in the world to use timber poles to provide habitat connectivity for a gliding mammal. The Australian squirrel glider Petaurus norfolcensis is a small tree-dependent gliding marsupial whose habitat is characterized by ongoing fragmentation. We installed five 12m-high poles across a 70m gap that had existed between two woodland remnants for over 45 years. Our aims were to determine whether animals were able to use the poles for gliding and to travel between the remnants. We released 22 animals onto the poles at night. All animals readily climbed and glided from the poles. Five individuals successfully glided pole-to-pole on initial release. Squirrel gliders were captured in both remnants only after pole erection and two were trapped on poles. One radio-collared individual was observed gliding pole-to-pole to reach the non-home remnant where it foraged on two separate nights. Petaurus hair was detected on several poles by hair-sampling devices in four separate periods up to 12 months after radio-tracking and trapping had ceased. Our observations suggest that wooden poles may assist gliding mammals to traverse open areas between habitat patches and have the potential to be used as a rapid technique to reconnect severed habitat. [Copyright &y& Elsevier]

Most studies on animal physiology and behaviour are conducted in captivity without verification that data are representative of free-ranging animals. We provide the first quantitative comparison of daily torpor, thermal biology and activity patterns, conducted on two groups of sugar gliders ( Petaurus breviceps, Marsupialia) exposed to similar thermal conditions, one in captivity and the other in the field. Our study shows that activity in captive gliders in an outdoor aviary is restricted to the night and largely unaffected by weather, whereas free-ranging gliders omit foraging on cold/wet nights and may also forage in the afternoon. Torpor occurrence in gliders was significantly lower in captivity (8.4% after food deprivation; 1.1% for all observations) than in the field (25.9%), mean torpor bout duration was shorter in captivity (6.9 h) than in the field (13.1 h), and mean body temperatures during torpor were higher in captivity (25.3°C) than in the field (19.6°C). Moreover, normothermic body temperature as a function of air temperature differed between captive and free-ranging gliders, with a >3°C difference at low air temperatures. Our comparison shows that activity patterns, thermal physiology, use of torpor and patterns of torpor may differ substantially between the laboratory and field, and provides further evidence that functional and behavioural data on captive individuals may not necessarily be representative of those living in the wild. [ABSTRACT FROM AUTHOR]

Single trees and small patches of trees in farmland are conspicuous components of agricultural landscapes around the world, but their value for the conservation of biodiversity is not well known. In this study, arboreal mammals were censused by using hair-sampling tubes in small patches of woodland (single trees to patches <1.0 ha) in cleared farmland adjacent to a linear network of woodland known to support resident populations of arboreal mammals. Ninety-one small isolates were stratified by size (single trees or small patches) and distance from the linear network to test the capacity of animals to cross habitat ‘gaps’. The genus Petaurus (small gliding marsupials), the most commonly detected taxon, was recorded in 31% of hair-tubes (98 of 316). It occurred in 21% of sites in isolated trees and patches, and in all linear strips. A logistic regression model demonstrated that Petaurus sp. was most likely to occur in isolates in close proximity to linear strips and other patches of woodland. Ninety-five per cent of sites at which this taxon occurred were within 75 m of the linear network. This threshold corresponds with the maximum distance that animals can glide in a single movement between trees. The size of isolates did not influence utilisation rates. Such isolates are smaller than a single home range and were probably used to supplement home ranges centred on the linear network, by providing additional foraging habitat and den sites. Protection and restoration of isolated trees and small woodland clumps in cleared landscapes contributes to mammal conservation and this study provides quantitative data that can assist landscape design and habitat restoration in rural environments. [Copyright &y& Elsevier]

Twenty seven sites, located in a range of sizes of bushland remnants (10 to >2000 ha) and spanning a range of altitudes (0–500 m), were surveyed for squirrel gliders. All sites were open forest or woodland with an overstorey of eucalyptus, although the floristic composition and physical structure of the habitat varied.The gliders were present in remnants as small as 10–20 ha, had higher densities in remnants between 200 and 1000 ha and were restricted to altitudes below 240 m. Squirrel gliders occurred mainly in areas containing plant species typical of drier eucalyptus open forest and woodland, and were less frequently located in vegetation containing eucalyptus and other plants typical of higher rainfall areas, near rainforest or along creeks and drainlines. Where gliders did occur, there was a significant positive correlation between glider abundance and the density of stags (standing dead trees) and trees (>1 m, >10 cm diameter at breast height (dbh)).Squirrel gliders in southeast Queensland appear to be quite tolerant of the current level of fragmentation of their habitat, but their persistence in the longer term will depend on retaining adequate cover of lowland eucalyptus forest and woodland, particularly the spotted gum—ironbark and related vegetation types. Further decrease in forest cover may reduce habitat linkages and result in the extirpation of this species from small remnants in which they currently occur. [Copyright &y& Elsevier]

Little information is available on seasonal changes in thermal physiology and energy expenditure in marsupials. To provide new information on the subject, we quantified how body mass, body composition, metabolic rate, maximum heat production, body temperature and thermal conductance change with season in sugar gliders (Petaurus breviceps) held in outdoor aviaries. Sugar gliders increased body mass in autumn to a peak in May/June, which was caused to a large extent by an increase in body fat content. Body mass then declined to minimum values in August/September. Resting metabolic rate both below and above the thermoneutral zone (TNZ) was higher in summer than in winter and the lower critical temperature of the TNZ occurred at a higher ambient temperature (Ta) in summer. The basal metabolic rate was as much as 45% below that predicted from allometric equations for placental mammals and was about 15% lower in winter than in summer. In contrast, maximum heat production was raised significantly by about 20% in winter. This, together with an approximately 20% decrease in thermal conductance, resulted in a 13°C reduction of the minimum effective Ta gliders were able to withstand. Our study provides the first evidence that, despite the apparent lack of functional brown adipose tissue, sugar gliders are able to significantly increase heat production in winter. Moreover, the lower thermoregulatory heat production at most Tas in winter, when food in the wild is scarce, should allow them to reduce energy expenditure. [ABSTRACT FROM AUTHOR]

Petaurus breviceps and Petaurus norfolcensis have produced hybrids in captivity, however there are no reported cases of Petaurus hybridisation in the wild. This study uses morphological data, mitochondrial DNA, and nuclear genome-wide SNP markers to confirm P. breviceps breviceps × P. norfolcensis hybridisation within their natural range on the central coast of New South Wales, Australia. Morphological data identified a potential hybrid that was confirmed with next-generation sequencing technology and 10,111 genome-wide SNPs. Both STRUCTURE and NewHybrid analyses identified the hybrid as a P. norfolcensis backcross, which suggests an initial F1 hybrid was fertile. The mitochondrial DNA matched that of a P. b. breviceps, indicating that a P. b. breviceps female initially mated with a P. norfolcensis male to produce a fertile female offspring. Our study is an important example of how genome-wide SNPs can be used to identify hybrids where the distribution of congeners overlaps. Hybridisation between congeners is likely to become more frequent as climate changes and habitats fragment, resulting in increased interactions and competition for resources and mates. [ABSTRACT FROM AUTHOR]

Habitat destruction is causing population decline of many hollow dependent species such as gliding marsupials of the Family Petauridae. Three petaurid species are now listed in some Australian states as either threatened, rare or vulnerable, precipitating a need for information on their basic biology and population structure. We isolated and characterized three polymorphic microsatellite loci from the yellow-bellied glider ( Petaurus australis) and six polymorphic microsatellite loci from the sugar glider ( P. breviceps). Per-locus heterozygosities range from 42%–92%, and cross-species amplification studies show that between five and seven loci are polymorphic in the two target species as well as a related species P. norfolcensis. [ABSTRACT FROM AUTHOR]