Reproduction and ontogeny of Mastacomys fuscus (Rodentia: Muridae) in the Australian Alps and comparisons with other small mammals living in alpine communities

Two species of small rodents, Mastacomys fuscus and Rattus fuscipes, and one small dasyurid marsupial Antechinus swainsonii live sympatrically in the subalpine habitat of SE Australia. This paper describes the reproductive characteristics and ontogeny of M. fuscus, and shows that the three species have different reproductive strategies that, in part, are a reflection of their different phylogenies. Cold and snow in winter, and a short summer season, limit the length of time available for reproduction and development. The rodent species exhibit similar reproductive characteristics to those in alpine regions of Europe, North America and South Africa.     

Genetic evidence for the origins of range disjunctions in the Australian dry sclerophyll plant Hardenbergia violacea

Aim The distribution of genetic variation in the Australian dry sclerophyll plant Hardenbergia violacea (Fabaceae) is examined in the context of Pleistocene climate change in order to identify likely refugia. Particular consideration is given to the origin of range disjunctions in South Australia and Tasmania, and to determining whether the Tasmanian population is indigenous or recently introduced from mainland Australia. Location Southeastern Australian mainland and Tasmania. Methods A combination of chloroplast polymerase chain reaction–restriction fragment length polymorphism and genomic amplified fragment length polymorphism (AFLP) marker systems was used to examine the genetic structure of 292 individuals from 13 populations across the range of H. violacea in southeastern Australia. Results Hardenbergia violacea populations in Tasmania and southern Victoria were characterized by low, almost monotypic chloroplast diversity. New South Wales showed higher haplotype diversity and haplotype sharing among widely distributed populations. Principal coordinates analysis (PCoA) of the AFLP data found a strong latitudinal cline in AFLP variation from northern New South Wales south to Tasmania. The Tasmanian population formed an isolated and somewhat disjunct genetic cluster at one end of this cline. However, the South Australian population was an exception to the clinal variation shown by all other populations, forming a highly disjunct cluster in the PCoA. Within‐population genetic diversity was low in both disjunct populations. Main conclusions The genetic evidence indicates that the Tasmanian population is likely to be indigenous and probably the product of vicariance, which was followed by range contraction at the Last Glacial Maximum or an earlier glacial event. The deep phylogenetic disjunction in South Australia is evidence of a much earlier separation on mainland Australia. The chloroplast structure indicates that, during the Pleistocene, H. violacea underwent broad‐scale recolonization in southern Victoria and Tasmania, possibly from a large continental refugium in eastern New South Wales. We conclude that H. violacea, and presumably the sclerophyll communities in which it occurs, have undergone multiple range contractions to large continental refugia during different Pleistocene glaciations in southeastern Australia.     

The occurrence of the Broad‐toothed Rat Mastacomys fuscus in relation to feral Horse impacts

Feral Horse (Equus caballus) impacts in northern Kosciuszko National Park, New South Wales, Australia are directly occurring in habitat of the nationally threatened Broad‐toothed Rat (Mastacomys fuscus). This species is endemic primarily to the mountain regions of south‐eastern mainland Australia and Tasmania, with a disjunct population at Barrington Tops. The Broad‐toothed Rat's preferred habitat is being increasingly impacted by browsing and trampling associated with the expansion of feral horse populations. This study surveyed 180 sites supporting preferred habitat for this species to determine Broad‐toothed Rat presence and relative abundance in relation to the level of feral horse impacts within the reserve. There was a significant negative relationship between feral horse impacts and both Broad‐toothed Rat presence and abundance. No scats were identified at localities where feral horse impacts were severe, and at moderate horse impact sites, there was a proportion (34%) without scats found. Locations with low horse impacts had little impact on Broad‐toothed Rat occurrence. As feral horse populations increase, Broad‐toothed Rat populations may be further impacted. Such impacts will be due to the loss of vegetation cover from feral horse trampling and grazing, making animals more vulnerable to predation by predators or impacting on their ability to disperse to more suitable habitat. Habitat remnants and vegetation corridors along drainage lines require protection from feral horses to prevent localized extinctions of Broad‐toothed Rat.     

Selective predation on the broad‐toothed rat,Mastacomys fuscus (Rodentia: Muridae), by the introduced red fox,Vulpes vulpes (Carnivora: Canidae), in the Snowy Mountains,Australia

Abstract Since 1981 there has been debate over whether foxes (Vulpes vulpes Linnaeus) selectively prey on the broad‐toothed rat (Mastacomys fuscus Thomas) relative to the bush rat (Rattus fuscipes (Waterhouse)). In the present study, three areas of the argument are examined. (i) In a study of fox diet over 3 years at both alpine and subalpine altitudes, M. fuscus outnumbered R. fuscipes in faecal remains in all seasons, in all years, and at both altitudes. Overall, M. fuscus occurred in scats five times as frequently as did R. fuscipes in the alpine zone and twice as often in the subalpine zone. (ii) Data from population studies of M. fuscus and R. fuscipes showed no evidence that M. fuscus is trap shy; neither the pattern of captures of individuals caught once, twice and so on, nor the proportion of the estimated population of each species captured during trapping sessions was significantly different. (iii) The suitable habitat for M. fuscus within the potential home ranges of foxes contributing to the subalpine fox scat collection constituted approximately 50% of the total area. However, there was no significant difference between the numbers of fox trails encountered in habitat suitable or unsuitable for M. fuscus in 19 paired transects skied in winter, indicating no preferential foraging in either habitat. Selective feeding on M. fuscus was therefore established, but how that choice is exercised was not determined.     

Phylogeography of colour polymorphism in the coral reef fish Pseudochromis fuscus, from Papua New Guinea and the Great Barrier Reef

Body colour has played a significant role in the evolution of coral reef fishes, but the phylogenetic level at which colour variation is expressed and the evolutionary processes driving the development and persistence of different colour patterns are often poorly understood. The aim of this study was to examine the genetic relationships between multiple colour morphs of Pseudochromis fuscus (family Pseudochromidae), both within and among geographic locations. Pseudochromis fuscus is currently described as a single species, but exhibits at least six discrete colour morphs throughout its range. In this study, P. fuscus from Papua New Guinea (PNG) and the Great Barrier Reef (GBR), Australia, formed three genetically distinct clades based on mitochondrial DNA (control region) sequence data: (1) yellow and brown morphs from the GBR and southern PNG, as well as an orange morph from southern PNG; (2) a pink morph from southern PNG; and (3) all three morphs (pink, orange and grey) found in Kimbe Bay, northern PNG. The three groups showed deep levels of divergence (d=14.6–25.4%), suggesting that P. fuscus is a complex of polychromatic species, rather than a single widespread species with many different colour morphs. Population genetic analyses indicate that the three clades have experienced unique evolutionary histories, possibly from differential effects of sea level fluctuations, barriers to gene flow and historical biogeography.     

Modelling the climate suitability of green carpenter bee (Xylocopa aerata) and its nesting hosts under current and future scenarios to guide conservation efforts

Due to local extinction, the endangered green carpenter bee (Xylocopa aerata) has a disjunct distribution in the southeast of Australia. The species relies on dead softwood from a small selection of plant species for making its nests. Habitat fragmentation, combined with deleterious fire events, is thought to have negatively impacted on nesting substrate availability and recolonisation chances. Here, we use MaxEnt algorithm to model both the current distribution and the effect of climate change scenarios on the distribution of both X. aerata and four plant species that provide most of its nesting substrate: Banksia integrifolia, B. marginata, Xanthorrhoea arborea and Xanthorrhoea semiplana subsp. tateana. The annual mean temperature is the strongest climatic predictor of the distribution of X. aerata and its host plants. The modelled distribution of the bee under current climatic conditions indicates that climatic factors are unlikely to cause local extinctions. In all future scenarios, suitable areas for X. aerata and each of its nesting hosts are expected to contract towards the southeast of mainland Australia. The suitability of Kangaroo Island for the bee and its current local current host species is maintained in all scenarios, while Tasmania will become increasingly suitable for all species. The Grampians National Park in western Victoria, where the bee species were last seen outside of its current range (in the 1930s), is predicted to remain suitable for X. aerata and several host plants under all scenarios. Therefore, this relatively large area of native vegetation may be a good case study for re‐introduction as part of future conservation efforts.     

Evolutionary history of the Maltese wall lizard Podarcis filfolensis: insights on the ‘Expansion–Contraction’ model of Pleistocene biogeography

The expansion–contraction (EC) model predicts demographic and range contraction of temperate species during Pleistocene glaciations as a consequence of climate‐related habitat changes, and provides a paradigm for explaining the high intraspecific diversity found in refugia in terms of long‐term demographic stability. However, recent evidence has revealed a weak predictive power of this model for terrestrial species in insular and coastal settings. We investigated the Pleistocene EC dynamics and their evolutionary consequences on temperate species using the Maltese archipelago and its endemic lizard Podarcis filfolensis as a model system. The evolutionary and demographic history of P. filfolensis as inferred from mitochondrial and nuclear sequences data does not conform to the EC model predictions, supporting (i) demographic and spatial stability or expansion, rather than contraction, of the northern and southern lineages during the last glacial period; and (ii) a major role for allopatric differentiation primed by sea‐level dynamics, rather than prolonged demographic stability, in the formation of the observed genetic diversity. When combined with evidence from other Mediterranean refugia, this study shows how the incorporation of Pleistocene sea‐level variations in the EC model accounts for a reverse demographic and range response of insular and coastal temperate biotas relative to continental ones. Furthermore, this cross‐archipelago pattern in which allopatric diversity is formed and shaped by EC cycles resembles that seen between isolated populations within mainland refugia and suggests that the EC model, originally developed to explain population fluctuations into and out‐of refugia, may be appropriate for describing the demographic and evolutionary dynamics driving the high genetic diversity observed in these areas.     

High levels of genetic divergence between Tasmanian and Victorian platypuses, Ornithorhynchus anatinus, as revealed by microsatellite loci

The platypus, Ornithorhynchus anatinus is a unique, iconic mammal endemic to Australia. Despite being listed as ‘common’ throughout its range, platypus abundance is poorly understood. Dependence on aquatic habitats in Australia renders this species potentially vulnerable to a variety of processes including drought, climate change and habitat loss. To assist with understanding population processes, 180 individuals from Tasmania and Victoria were characterised across thirteen microsatellite loci. Large genetic differences were evident between Tasmanian and Victorian O. anatinus. Within Tasmania, high levels of allelic diversity were detected with genetic differentiation identified among some populations. Similarly, allelic diversity was high within Victorian platypuses, along with significant genetic differentiation among populations. The large genetic differences found between Tasmanian and mainland platypuses indicate long-term isolation and it is likely that the lack of past/present catchment connectedness contributes to differentiation found between populations within these regions. Understanding patterns of genetic differentiation within and between catchments will help guide future conservation management decisions for platypus.     

Feral horse impacts on threatened plants and animals in sub‐alpine and montane environments in Victoria,Australia

Feral herbivores are a major driver of biodiversity loss globally and can alter the structure, composition and functioning of ecosystems. The direct impacts of feral herbivores on plant communities are well studied, but the direct and indirect effect they have on wildlife is not well understood. In Victoria (south‐eastern Australia), a large feral Horse (Equus caballus) population coincides with highly sensitive and nationally endangered Alpine Sphagnum Bogs and Associated Fens communities, and several threatened animal species. We assessed the impact of feral horses on this ecological community and the Alpine Water Skink (Eulamprus kosciuskoi) and the Broad‐toothed Rat (Mastacomys fuscus) at 20 sites with varying levels of horse disturbance. We used scat counts to determine an index of feral horse abundance and quantified impacts associated with their presence in the landscape. Active searches were used for Alpine Water Skink and scat and runway surveys for Broad‐toothed Rat. We also measured the vegetation structure and the abundance of different vegetation types (life forms). Our results suggest that feral horses are associated with vegetation types and characteristics that negatively influence the presence or abundance of Alpine Water Skink and Broad‐toothed Rat. Sites with high horse activity had more low‐growing forbs, and the abundance of Alpine Water Skink was negatively related to this vegetation type. Grasses, sedges, rushes and shrubs were also less dense and lower in height in high horse activity sites, and Broad‐toothed Rat was less likely to be present in areas with these habitat attributes. We recommend that feral horses are controlled to protect these threatened vertebrate species and their Sphagnum bog habitat.     

Whole range and regional‐based ecological niche models predict differing exposure to 21st century climate change in the key cool temperate rainforest tree southern beech (Nothofagus cunninghamii)

The warmer and drier climates projected for the mid‐ to late‐21st century may have particularly adverse impacts on the cool temperate rainforests of southeastern Australia. Southern beech (Nothofagus cunninghamii; Nothofagaceae), a dominant tree species in these forests, may be vulnerable to minor changes in its climate envelope, especially at the edge of the species range, with Holocene fossil evidence showing local extinction of populations in response to small climate changes. We modelled the stability of this species climate envelope using the maximum entropy algorithm implemented in Maxent and two thresholds of presence/absence by projecting the modern climate envelope onto four Global Circulation Models forecasted for two time periods (2050s and 2070s). The climate envelope, as estimated from the species present climatic range, is predicted to shrink by up to 49% by the 2050s and up to 64% by the 2070s. The greatest predicted reduction is in Victoria with 91–100% of its current range being climatically unsuitable by the 2070s. Climatically similar areas to the species present range are predicted to remain in mountainous areas of western Tasmania, the Northeast Highlands of Tasmania, and the Baw Baw Plateau in the Central Highlands of Victoria. However, region‐specific modelling approaches made very different predictions from the whole‐range based models, especially in the severity of the predicted decline for Victorian populations of N. cunninghamii which occur in much warmer climates than the rest of the species geographical range. This shows that, for widespread species that span a range of climate zones, the exposure of current populations to climate change may be better modelled using a regional based approach. How the species responds to climate change will depend on the species ability to respond to drier and warmer climates and the concomitant increase in fire intensity.     

Sea‐level changes and palaeo‐ranges: reconstruction of ancient shorelines and river drainages and the phylogeography of the Australian land crayfish Engaeus sericatus Clark (Decapoda: Parastacidae)

Historical sea levels have been influential in shaping the phylogeography of freshwater‐limited taxa via palaeodrainage and palaeoshoreline connections. In this study, we demonstrate an approach to phylogeographic analysis incorporating historical sea‐level information in a nested clade phylogeographic analysis (NCPA) framework, using burrowing freshwater crayfish as the model organism. Our study area focuses on the Bass Strait region of southeastern Australia, which is marine region encompassing a shallow seabed that has emerged as a land bridge during glacial cycles connecting mainland Australia and Tasmania. Bathymetric data were analysed using Geographical Information Systems (GIS) to delineate a palaeodrainage model when the palaeocoastline was 150 m below present‐day sea level. Such sea levels occurred at least twice in the past 500 000 years, perhaps more often or of larger magnitude within the last 10 million years, linking Victoria and Tasmania. Inter‐locality distance measures confined to the palaeodrainage network were incorporated into an NCPA of crayfish (Engaeus sericatus Clark 1936) mitochondrial 16S rDNA haplotypes. The results were then compared to NCPAs using present‐day river drainages and traditional great‐circle distance measures. NCPA inferences were cross‐examined using frequentist and Bayesian procedures in the context of geomorphological and historical sea‐level data. We found distribution of present‐day genetic variation in E. sericatus to be partly explained not only by connectivity through palaeodrainages but also via present‐day drainages or overland (great circle) routes. We recommend that future studies consider all three of these distance measures, especially for studies of coastally distributed species.     

Distribution of cryptic blue oat mite species in Australia: current and future climate conditions

• 1 Invertebrate pests, such as blue oat mites Penthaleus spp., cause significant economic damage to agricultural crops in Australia. Climate is a major driver of invertebrate species distributions and climate change is expected to shift pest assemblages and pest prevalence across Australia. At this stage, little is known of how individual species will respond to climate change.
• 2 We have mapped the current distribution for each of the three pest Penthaleus spp. in Australia and built ecological niche models for each species using the correlative modelling software, maxent . Predictor variables useful for describing the climate space of each species were determined and the models were projected into a range of future climate change scenarios to assess how climate change may alter species‐specific distribution patterns in Australia.
• 3 The distributions of the three cryptic Penthaleus spp. are best described with different sets of climatic variables. Suitable climate space for all species decreases under the climate change scenarios investigated in the present study. The models also indicate that the assemblage of Penthaleus spp. is likely to change across Australia, particularly in Western Australia, South Australia and Victoria.
• 4 These results show the distributions of the three Penthaleus spp. are correlated with different climatic variables, and that regional control of mite pests is likely to change in the future. A further understanding of ecological and physiological processes that may influence the distribution and pest status of mites is required.

     

Behavioral responses of Australian fur seals (Arctocephalus pusillus doriferus) to environmental variations

Observing how pinnipeds respond to variations in climatic and oceanographic conditions informs marine managers on factors that could limit their range, foraging ability and breeding success. Here, we examine how Australian fur seals (Arctocephalus pusillus doriferus) at Seal Rocks, Victoria, Australia, responded to normal climatic conditions from August 2009 to January 2010, which included their Austral spring‐summer breeding period, to investigate their tolerances to a range of environmental stimuli. Seal numbers ashore and a range of climatic variables were collected hourly during daylight periods and compared using Generalized Additive Mixed Models (GAMMs). Air temperature was the most consistent predictor of haul‐out behavior, with seal numbers ashore declining as air temperature increased (effect size ?50%, edf 1.00, P < 0.001). Increased wave height (effect size 74%, edf 1.00, P < 0.001) and wind speed (effect size 79%, edf 1.00, P < 0.001) were associated with increased seal numbers ashore. Potentially, higher air temperatures reduce the seals tolerance to remain out of the water, while high wind/wave action increases at‐sea metabolic costs. These results demonstrate how changes in climate could alter a seal's ability to remain ashore, to rest or breed, and its ability to forage effectively, thus driving changes in population status and range.     

Australian bird phenology: a search for climate signals

Temporal and climate‐related changes in avian phenology were assessed for seven species of south‐eastern Australia using data obtained from members of the public, naturalist groups and other organizations. Despite significantly warmer temperatures (～0.02–0.03°C per year) and reduced rainfall (～1.6–8.0 mm per year) over much of south‐eastern Australia in recent decades, most species showed no corresponding trends in their timing of migration or breeding, the notable exceptions being the grey fantail (Rhipidura fuliginosa) and the flame robin (Petroica phoenicea), which migrate through Melbourne, Victoria, during autumn and spring. In many species, however, migration or breeding timing appeared to be influenced to some extent by local, rather than regional, climate conditions, particularly local daily maximum and minimum temperatures. Whether these species will noticeably change their phenology to match projected changes in climate, perhaps when a currently unknown climate threshold is crossed, or whether these species are sufficiently flexible in their foraging strategies or food sources to be able to maintain their current timing, remains to be seen.     

Predicting the spread of Aedes albopictus in Australia under current and future climates: Multiple approaches and datasets to incorporate potential evolutionary divergence

When predicting the potential and future invasive range of a species, there is a growing appreciation that insights about factors limiting distributions can be provided by using multiple modelling approaches and by incorporating information from different parts of a species range. Here we apply this strategy to build on previous CLIMEX models to predict the invasion potential of Aedes albopictus, the Asian tiger mosquito, in mainland Australia. A combination of CLIMEX and MAXENT modelling indicated that the mosquito was expected to become widespread along the eastern seaboard and extend into northern Tasmania, but to remain restricted to the coastal fringe, a pattern which is not expected to shift much under climate change. However, a recent expansion of A. albopictus in North America points to evolutionary changes affecting the distribution of this species; when the North American range is included in models, A. albopictus is predicted to become much more widespread and extend inland and into Western Australia. These patterns highlight the potential impact of evolution on species distributions arising from multiple introductions or in situ evolution. By considering future climate scenarios, we demonstrate that there is likely to be a persistent public health threat associated with invasion by this species.     

Reproductive potential of a marine ecosystem engineer at the edge of a newly expanded range

Global climate change is leading to redistribution of marine species and altering ecosystem dynamics. Given recent poleward range extension of the barrens‐forming sea urchin Centrostephanus rodgersii (Diadematidae) from mainland Australia to Tasmania, there is a need to understand the population dynamics of this ecologically important species in the Tasmanian environment. This paper informs possible population dynamics of C. rodgersii in Tasmania by examining its reproductive ecology in this new environment. Reproductive periodicity (gonad index and propensity to spawn) was assessed bimonthly over 18 months at four sites in eastern Tasmania spanning ～2° in latitude. At all sites, C. rodgersii displayed a strong seasonal cycle in gonad production with major spawning occurring in winter (～August) at minimum annual water temperature. Gametes from Tasmanian C. rodgersii were viable as determined by fertilization and early development trials. However, development to the two‐arm stage at ～3 weeks was strongly dependent on water temperature across the 8–20 °C temperature range, with poor development occurring below 12 °C. The range of temperatures tolerated by Tasmanian C. rodgersii larvae was similar to that of larvae from its native New South Wales range, indicating that this species has not undergone an adaptive shift to the cooler Tasmanian environment. There was also no evidence for an adaptive shift in reproductive phenology. Importantly, coastal water temperatures in eastern Tasmania during the peak spawning in August fluctuate about the 12 °C larval development threshold. Recent warming of the eastern Tasmanian coast and further warming predicted by global climate change will result in an environment increasingly favourable for the reproduction and development of C. rodgersii.     

A technique for using hair tubes beneath the snowpack to detect winter-active small mammals in the subnivean space

The study of winter-active small mammals beneath the snowpack has proved challenging for researchers because of the relative inaccessibility. We present a technique using hair tubes that permits the detection of small mammals active in the subnivean space. Hair tubes are cylindrical or funnel-shaped structures containing suitable bait and an adhesive surface that harvests hairs from small mammals as they attempt to reach the bait. Hair tubes eliminate many of the difficulties often associated with live trapping and permit the expansion of systematic sampling to larger scales than allowed by conventional live-trapping methods. The technique was used successfully to detect five small mammal species in the subnivean space in Kosciuszko National Park (KNP) in southeastern Australia. These included the common bush-rat, Rattus fuscipes; the dusky and agile antechinus, Antechinus swainsonii and A. agilis; the broad-toothed rat, Mastacomys fuscus; and the mountain pygmy possum, Burramys parvus. Although hair tubes have a number of limitations, such as not providing a measure of abundance or allowing the identification of individual animals, we believe that these limitations are balanced by the fact that the technique can be used at any spatial scale. Hair tubes are particularly suited to studies of animal distribution at the landscape-scale, because many hair tubes can be deployed and dispersed over large areas, and monitored on a regular basis by a small team of researchers. The technique also makes use of readily available, low-cost materials and could be easily adapted to a range of conditions and different target species.     

Using multiple‐source occurrence data to identify patterns and drivers of decline in arid‐dwelling Australian marsupials

Many of the world's terrestrial mammal species are imperilled, but recent extinctions and declines have been most severe in Australia. In particular, arid‐dwelling marsupials in a critical weight range (35–5500 g) have declined dramatically following European settlement. In the absence of long‐term monitoring, documenting these declines or distribution shifts and their causes often relies on occurrence data from multiple sources. Using atlas records, we compared the distributions of all currently extant marsupials in the critical weight range in Australia's arid Northern Territory pre‐ and post‐1975. For taxa with evidence of range contraction, we evaluated alternative hypotheses to explain this contraction (i.e. competition, predation, productivity, climate) using several techniques to improve our confidence in the results. Despite a substantial increase in the number of mammal records across the study region post‐1975, the bilby Macrotis lagotis and desert form of the common brushtail possum Trichosurus vulpecula appear to have contracted in distribution by 25 and 40%, respectively. These changes in distribution were best explained by hypotheses of competition and climate‐change, respectively. Macrotis lagotis was more likely to occur on land without a history of cattle grazing and with low rabbit densities, while T. vulpecula has contracted to parts of its distribution that experience cooler maximum temperatures over the hottest months of the year. For five other taxa (including the vulnerable black‐footed rock‐wallaby Petrogale lateralis) we recorded increases in distribution post‐1975, probably reflecting increased survey effort rather than actual range expansion. We conclude that models using multiple‐source occurrence data can provide key insights into the patterns and drivers of contemporary species’ declines, and represent useful tools for conservation.     

The spread of the social wasp,Vespula germanica,in Australia

Abstract

Between 1977 and 1989 the social wasp Vespula germanicacolonised mainland Australia and became established in New South Wales, Victoria, and South Australia. Accidental transport between towns is the main mechanism of spread. In many towns wasp nests have not been detected until they became widespread; therefore, eradication is difficult Successful eradication has, however, been achieved in many other towns.

Nesting places vary considerably among localities but relatively little among years at anyone locality. Peak wasp abundance occurs between January and April. Control of V. germanica nests costs Australia an estimated $600,000 (Aust. $) annually.     

Modelling changes in the distribution of the critical food resources of a specialist folivore in response to climate change

Aim An important consideration when planning to conserve a species under climate change is to understand how the distribution of its food resources may also contract or shift under those same climatic conditions. Here, we use a case study to demonstrate a spatial conservation planning approach to inform decisions about where, under climate change, to protect and restore critical food and habitat resources for highly specialized species. Location Eastern Australia. Methods We developed fitted models for the koala (Phascolarctos cinereus) and five of its key eucalypt food trees using the maximum entropy algorithm available in Maxent. We then projected these models using a range of IPCC A1FI climate change scenarios and identified areas with a higher probability of occurrence. We calculated where the koala and its food trees may co‐occur under future climate change. Results The koala and its food trees experienced significant range contractions as climate change progressed, sometimes to regions outside their current distributions. The inland species Eucalyptus camaldulensis and Eucalyptus coolabah contracted from the more arid interior, which is outside the koala range, but persisted in the eastern regions of the koala’s range, while Eucalyptus viminalis, Eucalyptus populnea and Eucalyptus tereticornis contracted eastwards and southwards, with a fragmented distribution. The highest probabilities of overlap between koalas and their food trees were identified in fragmented coastal and southern regions of the koala’s current range. Main conclusions The application of a robust species distribution modelling decision support tool identified important changes, under climate change, in the distribution of a specialist species and its key food trees. These distributions did not change in complete synergy and therefore areas of overlap varied, depending on the food tree species modelled. This is of particular importance in a conservation planning context, when considering targeted protection and restoration of species‐specific habitat resources.