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Simple Summary: Invasive alien species, such as Carpomya vesuviana Costa (Diptera: Tephritidae), threaten global biodiversity, agriculture, and public health. This study used advanced modelling techniques to predict the potential distribution of C. vesuviana and understand its environmental impacts. The findings suggest that climate change is driving the geographic expansion of C. vesuviana, primarily in Asia, Africa, and Australia. The species is projected to shift poleward by the 2090s, as the species will have shifted to the polar regions under the influence of climate change. Effective management strategies are crucial to mitigate the environmental and health impacts of its expansion. Invasive alien species (IAS) significantly affect global native biodiversity, agriculture, industry, and human health. Carpomya vesuviana Costa, 1854 (Diptera: Tephritidae), a significant global IAS, affects various date species, leading to substantial economic losses and adverse effects on human health and the environment. This study employed biomod2 ensemble models, multivariate environmental similarity surface and most dissimilar variable analyses, and ecological niche dynamics based on environmental and species data to predict the potential distribution of C. vesuviana and explore the environmental variables affecting observed patterns and impacts. Compared to native ranges, ecological niche shifts at invaded sites increased the invasion risk of C. vesuviana globally. The potential geographical distribution was primarily in Asia, Africa, and Australia, with a gradual increase in suitability with time and radiation levels. The potential geographic distribution centre of C. vesuviana is likely to shift poleward between the present and the 2090s. We also show that precipitation is a key factor influencing the likely future distribution of this species. In conclusion, climate change has facilitated the expansion of the geographic range and ecological niche of C. vesuviana, requiring effective transnational management strategies to mitigate its impacts on the natural environment and public health during the Anthropocene. This study aims to assess the potential threat of C. vesuviana to date palms globally through quantitative analytical methods. By modelling and analysing its potential geographic distribution, ecological niche, and environmental similarities, this paper predicts the pest's dispersal potential and possible transfer trends in geographic centres of mass in order to provide prevention and control strategies for the global date palm industry. [ABSTRACT FROM AUTHOR]

Comments are presented on an article published in October 2020 in Ecology and Evolution ("Predictive ability of a process‐based versus a correlative species distribution model") by Higgins et al. This analyzed natural distributions of Australian eucalypt and acacia species and assessed the adventive range of selected species outside Australia. Unfortunately, inappropriate variables were used with the MaxEnt species distribution model outside Australia, so that large climatically suitable areas in the Northern Hemisphere were not identified. Examples from a previous analysis and from the use of the freely available spatial portal of the Atlas of Living Australia are provided to illustrate how the problem can be overcome. The comparison of methods described in the Higgins et al. paper is worthwhile, and it is hoped that the authors will be able to repeat their analyses using appropriate variables with the correlative model. [ABSTRACT FROM AUTHOR]

This review clarifies important points on habitat selection by the Swamp Rat Rattus lutreolus (Rodentia: Muridae), a species that has been the subject of much research in Australia and has provided a useful model for understanding ecological and biological processes. It also provides an opportunity to cite important earlier research, not readily available through electronic search engines, thus bringing it into current literature to avoid its disappearance into Internet obscurity. We comment on some papers in the literature to correct errors detected and to emphasize the importance of due care in all aspects of a research project, including its reporting. We show that both floristic and structural components have been reported as important to an understanding of habitat and microhabitat selection by R. lutreolus and conclude that it is vegetation density that is of paramount importance. Female R. lutreolus are clearly dominant in driving microhabitat selection, occupying the ‘best’ or densest habitats with male R. lutreolus occupying the next best and Pseudomys or other species, where present occupying the remainder. This demonstrates the important role that intraspecific and interspecific competition play in determining habitat selection. Direct predation and the perception of predation risk may also play a role in habitat selection, again perceived to be pushing individuals towards denser vegetation, representing ‘better cover’. Whether these effects operate as bottom-up or top-down needs careful consideration. Climatic variables, such as ENSO-affecting productivity, and related variables such as temperature and humidity may also play important roles in habitat selection, as can disturbance effects such as wildfire. The relative importance of all of these potential determining factors may vary from place to place, particularly when climatic clines are involved. [ABSTRACT FROM AUTHOR]

The 19 BIOCLIM variables available from the WorldClim databases have become the most widely used set of climatic variables for creating species distribution models (SDMs) and ecological niche models (ENMs). Nevertheless, in recent years, there has been an increasing trend to exclude four of these variables from SDM/ENM analyses. The four values concerned are interactive as they combine both temperature and precipitation assessments. Their exclusion was justified initially due to discontinuities in their interpolated surfaces observed in a study using data from version 1 of WorldClim. The discontinuities were thought to be artefacts of the measures used, and such sudden changes were unlikely to be biologically meaningful. A freely available biodiversity database and an open access geographic information system were used here to check the four interactive variables for discontinuities in data from both versions 1 and 2 of WorldClim. Over most of the world, the four interactive BIOCLIM variables from WorldClim were found to change smoothly. Major and minor discontinuities, however, were noted for all four variables in specific parts of some of the six continents (excluding Antarctica) covered by WorldClim databases. Discontinuities were related to sudden changes in the quarterly periods used to calculate the variables. These discontinuities were often found in equatorial regions where there are only small changes in temperature across the year. Bimodal precipitation distributions may also cause problems. It is recommended that the quick and simple method described here should be used to facilitate visual inspection and numerical checking for possible discontinuities of these variables before SDM/ENM analyses. If discontinuities are found for an interactive variable in the study area, it is recommended that the variable should not be used. Ways in which the four variables could be recalculated when new databases are created are suggested to reduce discontinuity problems. [ABSTRACT FROM AUTHOR]

Questions: For eucalypt savanna in northeast Australia subject to multi-year rainfall deficits this paper asks whether (1) dominant tree species (Ironbarks, Boxes) are more drought susceptible than the sub-dominant Bloodwoods; (2) whether soil moisture is beyond wilting point in surface soil layers but available at depth; (3) soil conditions (moisture availability and texture) are related to tree death during drought; (4) the root systems of the Boxes and Ironbarks are shallower than the Bloodwoods; and the survivors of drought within species have deeper root systems than those that died. Location: Central Queensland, Australia. Methods: Patterns of tree death between eucalypt species were compared from field data collected after drought. Soil conditions during drought were described and compared with patterns of tree death for the Ironbark Eucalyptus melanophloia. The basal area and orientation of coarse roots were measured on upturned trees after broad-scale tree clearing, and compared between species, and between live and dead trees with tree size as a covariate. Results: Drought-induced tree death was higher for dominant Ironbark-Box than for sub-dominant Bloodwoods. During a moderate to severe drought in 2004, 41% of 100 cm deep subsoils had soil matric potential less than—5600 kPa. The drought hardy Bloodwoods had a greater root basal area and particularly so for vertical roots compared to the drought sensitive Ironbark- Box. Within species there was no significant difference in root basal area characteristics between trees that were recently killed by drought and those that remained relatively healthy. Surface soil moisture availability was lower where tree densities were high, and tree death increased as surface soil moisture became less available. Tree death was also greater as the clay content of sub-soils increased. Discussion: The study suggests species with roots confined to upper soil layers will suffer severe water stress. The results strongly indicate that root architecture, and the way it facilitates water use during drought, is important for the relative dominance of the tree species. Patchiness in drought-induced tree death seems to be at least partially a product of heterogeneity in sub-soil conditions and competition for soil moisture. [ABSTRACT FROM AUTHOR]

The thylacine, or Tasmanian tiger, is the largest of modern-day carnivorous marsupials and was hunted to extinction by European settlers in Australia. Its physical resemblance to eutherian wolves is a striking example of evolutionary convergence to similar ecological niches. However, whether the neuroanatomical organization of the thylacine brain resembles that of canids and how it compares with other mammals remain unknown due to the scarcity of available samples. Here, we gained access to a century-old hematoxylin-stained histological series of a thylacine brain, digitalized it at high resolution, and compared its forebrain cellular architecture with 34 extant species of monotremes, marsupials, and eutherians. Phylogenetically informed comparisons of cortical folding, regional volumes, and cell sizes and densities across cortical areas and layers provide evidence against brain convergences with canids, instead demonstrating features typical of marsupials, and more specifically Dasyuridae, along with traits that scale similarly with brain size across mammals. Enlarged olfactory, limbic, and neocortical areas suggest a small-prey predator and/or scavenging lifestyle, similar to extant quolls and Tasmanian devils. These findings are consistent with a nonuniformity of trait convergences, with brain traits clustering more with phylogeny and head/body traits with lifestyle. By making this resource publicly available as rapid web-accessible, hierarchically organized, multiresolution images for perpetuity, we anticipate that additional comparative insights might arise from detailed studies of the thylacine brain and encourage researchers and curators to share, annotate, and preserve understudied material of outstanding biological relevance. [ABSTRACT FROM AUTHOR]

The International Panel on Climate Change (IPCC) projects a global temperature rise of 4.3 ± 0.7 °C by 2100 and an extinction of 8.5% in one out of every six species. Australia's aquatic ecosystem is no exception; habitat loss, fragmentation, and loss of biodiversity are being experienced. As the center for Nymphaea species distribution, it presents the culturally, ecologically, and scientifically important genus as the best candidate for habitat suitability assessment in climate change, whose habitat suitability is presumed to decline. The models were run according to the maximum entropy (MaxEnt) method, using one general circulation model (GCM). Projections were made for the current, past, and future in medium (4.5) and high (8.5) representative concentration pathways. Significantly, bio2 and bio15 were highly preferred among the species. Less distribution was noted in West Australia compared to the north, east, and south of the continent, while north of the continent in Western Australia, Northern Territory, and Queensland indicate more habitat contractions compared to the east and southeast of Queensland and New South Wales, although it receives high precipitation. Generally, the species respond variably to both temperature and precipitation variables which is a key species response factor for planners and decision makers in species habitat and biodiversity conservation. [ABSTRACT FROM AUTHOR]

Constraining the timing of morphological innovations within xiphosurid evolution is central for understanding when and how such a long-lived group exploited vacant ecological niches over the majority of the Phanerozoic. To expand the knowledge on the evolution of select xiphosurid forms, we reconsider the four Australian taxa: Austrolimulus fletcheri, Dubbolimulus peetae, Tasmaniolimulus patersoni, and Victalimulus mcqueeni. In revisiting these taxa, we determine that, contrary to previous suggestion, T. patersoni arose after the Permian and the origin of over-developed genal spine structures within Austrolimulidae is exclusive to the Triassic. To increase the availability of morphological data pertaining to these unique forms, we also examined the holotypes of the four xiphosurids using synchrotron radiation X-ray tomography (SRXT). Such non-destructive, in situ imaging of palaeontological specimens can aid in the identification of novel morphological data by obviating the need for potentially extensive preparation of fossils from the surrounding rock matrix. This is particularly important for rare and/or delicate holotypes. Here, SRXT was used to emphasize A. fletcheri and T. patersoni cardiac lobe morphologies and illustrate aspects of the V. mcqueeni thoracetronic doublure, appendage impressions, and moveable spine notches. Unfortunately, the strongly compacted D. peetae precluded the identification of any internal structures, but appendage impressions were observed. The application of computational fluid dynamics to high-resolution 3D reconstructions are proposed to understand the hydrodynamic properties of divergent genal spine morphologies of austrolimulid xiphosurids. [ABSTRACT FROM AUTHOR]

Foundation species interact strongly with other species to profoundly influence communities, such as by providing food, refuge from predators or beneficial microclimates. We tested relative support for these mechanisms using spinifex grass (Triodia spp.), which is a foundation species of arid Australia that provides habitat for diverse lizard communities. We first compared the attributes of live and dead spinifex, bare ground and a structurally similar plant (Lomandra effusa), and then tested the relative strength of association of two spinifex specialist lizard species (Ctenophorus spinodomus and Ctenotus atlas) with spinifex using a mesocosm experiment. Temperatures were coolest within spinifex compared to bare ground and Lomandra. Invertebrate abundance and the threat of predation were indistinguishable between treatments, suggesting temperature attenuation may be a more important driver. Overall, the dragon C. spinodomus preferred live over dead spinifex, while the skink C. atlas preferred dead spinifex, particularly at warmer air temperatures. However, both species displayed individual variability in their use of available microhabitats, with some individuals rarely using spinifex. Our results provide an example of temperature attenuation by a foundation species driving niche use by ectothermic animals. [ABSTRACT FROM AUTHOR]

Aim: The Tawny Coster Acraea terpsicore is a highly mobile butterfly that has recently expanded its spatial distribution from South Asia to South‐East Asia and Australia. Here, we determine if the realized climatic niche has changed during the expansion and analyse the geographic pattern of spread in Australia. Location: Asia and Australia. Methods: We collated occurrence records, divided the geographic range into three spatio‐temporal phases (pre‐expansion, early‐expansion and late‐expansion) and then developed ecological niche models for each phase. To determine whether the realized niche has changed during the range expansion, we performed a principal component analyses and niche overlap analysis. Finally, we calculated the annual rate of range expansion to estimate the speed and pattern of geographic spread. Results: The climatic niche of A. terpsicore differs only slightly in the pre‐expansion and late‐expansion ranges and was most distinct in the early‐expansion range. The species' range in Australia expanded at an average rate of ~ 135 km/year (range: 34–359 km/year). Female‐biased migration occurred in north‐eastern Queensland at the leading edge of the range, the first documentation of this phenomenon in butterflies. Main Conclusions: Acraea terpsicore represents one of the fastest documented geographic range expansions of any species, highlighting how rapidly butterflies can colonize new areas, even where environmental conditions are substantially different to those in their original distribution. However, we found little evidence of climatic niche shift, and only a minor niche shift is apparent in the early‐expansion and late‐expansion ranges. It remains unclear what triggered the sudden expansion, but it has been hypothesized that tropical deforestation provided conditions that initiated local range expansion, and further work on the possible mechanisms involved is required. [ABSTRACT FROM AUTHOR]

Aims Invasive species, which recently expanded, may help understand how climatic niche can shift at the time scale of the current global change. Here, we address the climatic niche shift of an invasive shrub (common gorse, Ulex europaeus) at the world and regional scales to assess how it could contribute to increasing invasibility. Methods Based on a 28 187 occurrences database, we used a combination of 9 species distribution models (SDM) to assess regional climatic niche from both the native range (Western Europe) and the introduced range in different parts of the world (North-West America, South America, North Europe, Australia and New Zealand). Important Findings Despite being restricted to annual mean temperature between 4°C and 22°C, as well as annual precipitation higher than 300 mm/year, the range of bioclimatic conditions suitable for gorse was very large. Based on a native versus introduced SDM comparison, we highlighted a niche expansion in North-West America, South America and to a lesser degree in Australia, while a niche displacement was assessed in North Europe. These niche changes induced an increase in potential occupied areas by gorse by 49, 111, 202 and 283% in Australia, North Europe, North-West America and South America, respectively. On the contrary, we found no evidence of niche change in New Zealand, which presents similar climatic condition to the native environment (Western Europe). This study highlights how niche expansion and displacement of gorse might increase invasibility at regional scale. The change in gorse niche toward new climatic conditions may result from adaptive plasticity or genetic evolution and may explain why it has such a high level of invasibility. Taking into account the possibility of a niche shift is crucial to improve invasive plants management and control. [ABSTRACT FROM AUTHOR]

Echidnas are egg‐laying mammals found across Australia, and in Tasmania they hibernate, resulting in a most unusual mating system: males enter hibernation in late summer–early autumn and arouse in late autumn–early winter to mate, although females are still hibernating. Groups of males compete for matings and both males and females mate with multiple partners. Females that mate early return to hibernation even when pregnant, and males continue to mate with pregnant females. We asked to what extent can the bizarre combination of behavioural and physiological features that characterize reproduction of Tasmanian echidnas be attributed to their phylogeny, and how much is a consequence of their ecology?To understand the interaction between energetics and the echidna mating system in determining the timing of echidna hibernation, we analysed data from an 18‐year study of a wild population of Tasmanian echidnas (Tachyglossus aculeatus setosus)Males in best condition arouse earliest and seek out suitable females, and females that mate early in the mating season re‐enter hibernation while pregnant.Competition between males drives early mating and while mating with males in the best condition could be advantageous for females and their young, egg‐laying in winter is potentially disadvantageous, and post‐mating hibernation by females is a means of delaying hatching of young until environmental conditions are more favourable. This post‐mating hibernation by females is usually disrupted by males which mate with them although they are already pregnant.Comparisons with other echidna populations suggest that a decreased activity period due to hibernation has not increased male–male competition.Similar competition between groups of males for access to females is seen in chlamyphorid armadillos, which occupy a similar ecological niche to echidnas. A free Plain Language Summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

Orchids are generally regarded as plants with an insignificant invasive potential and so far only one species has proved to be harmful for native flora. However, previous studies on Epipactis helleborine and Arundina graminifolia indicate that the ecological aspects of range extension in their non-native geographical range are not the same for all species of orchids. Disa bracteata in its native range, South Africa, is categorized as of little concern in terms of conservation whereas in Australia it is naturalized and considered to be an environmental weed. The aim of this research was to determine the ecological preferences enabling the spread of Disa bracteata in Western and South Australia, Victoria and Tasmania and to evaluate the effect of future climate change on its potential range. The ecological niche modeling approach indicates that most of the accessible areas are already occupied by this species but future expansion will continue based on four climate change scenarios (rcp26, rcp45, rcp60, rcp85). Further expansion is predicted especially in eastern Australia and eastern Tasmania. Moreover, there are some unpopulated but suitable habitats in New Zealand, which according to climate change scenarios will become even more suitable in the future. The most striking result of this study is the significant difference between the environmental conditions recorded in the areas which D. bracteata naturally inhabits and invasive sites—that indicates a possible niche shift. In Australia the studied species continues to populate a new niche or exploit habitats that are only moderately represented in South Africa. [ABSTRACT FROM AUTHOR]

Summary: Over nearly three decades, Suzanne Prober has played a pivotal role in shifting research in Australian agricultural landscapes to include a focus on native woodlands, and to examine ways woodland conservation can co‐exist with production, contributing to new models for conservation within multi‐use landscapes. [ABSTRACT FROM AUTHOR]

Hendra virus (HeV), a highly pathogenic zoonotic paramyxovirus recently emerged from bats, is a major concern to the horse industry in Australia. Previous research has shown that higher temperatures led to lower virus survival rates in the laboratory. We develop a model of survival of HeV in the environment as influenced by temperature. We used 20 years of daily temperature at six locations spanning the geographic range of reported HeV incidents to simulate the temporal and spatial impacts of temperature on HeV survival. At any location, simulated virus survival was greater in winter than in summer, and in any month of the year, survival was higher in higher latitudes. At any location, year-to-year variation in virus survival 24 h post-excretion was substantial and was as large as the difference between locations. Survival was higher in microhabitats with lower than ambient temperature, and when environmental exposure was shorter. The within-year pattern of virus survival mirrored the cumulative within-year occurrence of reported HeV cases, although there were no overall differences in survival in HeV case years and non-case years. The model examines the effect of temperature in isolation; actual virus survivability will reflect the effect of additional environmental factors. [ABSTRACT FROM AUTHOR]

Tropical rainforest canopies are renowned for their high invertebrate diversity and abundance. The canopy comprises a range of microhabitats representing very different food resources (including photosynthetic, reproductive, and structural tissues). As these resources vary considerably in temporal and spatial availability, nutritional quality, chemical protection and other attributes, we hypothesized that microhabitats support structurally different invertebrate communities. To test this we used the Australian Canopy Crane to sample invertebrates from mature leaves, flush leaves, flowers, fruit and suspended dead wood from 23 plant species. Invertebrate faunas on different microhabitats varied in taxonomic composition and feeding guild structure in support of the microhabitat differentiation hypothesis. Herbivores were found predominantly on new leaves ( Hemiptera, Lepidoptera) and especially flowers ( Coleoptera, Thysanoptera), but were relatively uncommon on mature leaves. Instead, the mature foliage community was dominated by predators, especially spiders and ants, and supported high abundances of saprophages. Ripe fruit and dead wood were scarce canopy resources that were utilized by a relatively small number of invertebrates, mostly saprophages and fungivores. Flowers supported a more heterogeneous fauna than the leaves in terms of proportional abundances of taxonomic groups and feeding guilds, both within tree species (evenness) and between tree species (non-uniformity). These results demonstrate microhabitat differentiation in a rainforest canopy and are the first to quantify differences in taxonomic composition, guild structure and abundance patterns between such diverse invertebrate assemblages within host trees. We conclude that studies based only on sampling one microhabitat, and leaves in particular, may provide a distorted picture of invertebrate community structure. [ABSTRACT FROM AUTHOR]

Transposable elements (TEs), also known as jumping genes, are sequences able to move or copy themselves within a genome. As TEs move throughout genomes they often act as a source of genetic novelty, hence understanding TE evolution within lineages may help in understanding environmental adaptation. Studies into the TE content of lineages of mammals such as bats have uncovered horizontal transposon transfer (HTT) into these lineages, with squamates often also containing the same TEs. Despite the repeated finding of HTT into squamates, little comparative research has examined the evolution of TEs within squamates. Here we examine a diverse family of Australo–Melanesian snakes (Hydrophiinae) to examine if the previously identified, order-wide pattern of variable TE content and activity holds true on a smaller scale. Hydrophiinae diverged from Asian elapids ~30 Mya and have since rapidly diversified into six amphibious, ~60 marine and ~100 terrestrial species that fill a broad range of ecological niches. We find TE diversity and expansion differs between hydrophiines and their Asian relatives and identify multiple HTTs into Hydrophiinae, including three likely transferred into the ancestral hydrophiine from fish. These HTT events provide the first tangible evidence that Hydrophiinae reached Australia from Asia via a marine route. [ABSTRACT FROM AUTHOR]

The thermal reaction norms of 4 closely related intertidal Nacellid limpets, Antarctic (Nacella concinna), New Zealand (Cellana ornata), Australia (C. tramoserica) and Singapore (C. radiata), were compared across environments with different temperature magnitude, variability and predictability, to test their relative vulnerability to different scales of climate warming. Lethal limits were measured alongside a newly developed metric of "duration tenacity", which was tested at different temperatures to calculate the thermal reaction norm of limpet adductor muscle fatigue. Except in C. tramoserica which had a wide optimum range with two break points, duration tenacity did not follow a typical aerobic capacity curve but was best described by a single break point at an optimum temperature. Thermal reaction norms were shifted to warmer temperatures in warmer environments; the optimum temperature for tenacity (Topt) increased from 1.0 °C (N. concinna) to 14.3 °C (C. ornata) to 18.0 °C (an average for the optimum range of C. tramoserica) to 27.6 °C (C. radiata). The temperature limits for duration tenacity of the 4 species were most consistently correlated with both maximum sea surface temperature and summer maximum in situ habitat logger temperature. Tropical C. radiata, which lives in the least variable and most predictable environment, generally had the lowest warming tolerance and thermal safety margin (WT and TSM; respectively the thermal buffer of CTmax and Topt over habitat temperature). However, the two temperate species, C. ornata and C. tramoserica, which live in a variable and seasonally unpredictable microhabitat, had the lowest TSM relative to in situ logger temperature. N. concinna which lives in the most variable, but seasonally predictable microhabitat, generally had the highest TSMs. Intertidal animals live at the highly variable interface between terrestrial and marine biomes and even small changes in the magnitude and predictability of their environment could markedly influence their future distributions. [ABSTRACT FROM AUTHOR]

Estimates suggest that perhaps 40% of all invertebrate species are found in tropical rainforest canopies. Extrapolations of total diversity and food web analyses have been based almost exclusively on species inhabiting the foliage, under the assumption that foliage samples are representative of the entire canopy. We examined the validity of this assumption by comparing the density of invertebrates and the species richness of beetles across three canopy microhabitats (mature leaves, new leaves and flowers) on a one hectare plot in an Australian tropical rainforest. Specifically, we tested two hypotheses: 1) canopy invertebrate density and species richness are directly proportional to the amount of resource available; and 2) canopy microhabitats represent discrete resources that are utilised by their own specialised invertebrate communities. We show that flowers in the canopy support invertebrate densities that are ten to ten thousand times greater than on the nearby foliage when expressed on a per-unit resource biomass basis. Furthermore, species-level analyses of the beetle fauna revealed that flowers support a unique and remarkably rich fauna compared to foliage, with very little species overlap between microhabitats. We reject the hypothesis that the insect fauna on mature foliage is representative of the greater canopy community even though mature foliage comprises a very large proportion of canopy plant biomass. Although the significance of the evolutionary relationship between flowers and insects is well known with respect to plant reproduction, less is known about the importance of flowers as resources for tropical insects. Consequently, we suggest that this constitutes a more important piece of the 'diversity jigsaw puzzle' than has been previously recognised and could alter our understanding of the evolution of plant-herbivore interactions and food web dynamics, and provide a better foundation for accurately estimating global species richness. [ABSTRACT FROM AUTHOR]

Aim Niche conservatism is key to understanding species responses to environmental stress such as climate change or arriving in new geographical space such as biological invasion. Halotydeus destructor is an important agricultural pest in Australia and has been the focus of extensive surveys that suggest this species has undergone a niche shift to expand its invasive range inland to hotter and drier environments. We employ modern correlative modelling methods to examine niche conservatism in H. destructor and highlight ecological differences between historical and current distributions. Location Australia and South Africa. Methods We compile comprehensive distribution data sets for H. destructor, representing the native range in South Africa, its invasive range in Australia in the 1960s (40 yr post-introduction) and its current range in Australia. Using MAXENT, we build correlative models and reciprocally project them between South Africa and Australia and investigate range expansion with models constructed for historical and current data sets. We use several recently developed model exploration tools to examine the climate similarity between native and invasive ranges and subsequently examine climatic variables that limit distributions. Results The invasive niche of H. destructor in Australia transgresses the native niche in South Africa, and the species has expanded in Australia beyond what is predicted from the native distribution. Our models support the notion that H. destructor has undergone a more recent range shift into hotter and drier inland areas of Australia since establishing a stable distribution in the 1960s. Main conclusions Our use of historical and current data highlights that invasion is an ongoing dynamic process and demonstrates that once a species has reached an established range, it may still expand at a later stage. We also show that model exploration tools help understand factors influencing the range of invasive species. The models generate hypotheses about adaptive shifts in H. destructor. [ABSTRACT FROM AUTHOR]

Aim Investigate the relative abilities of different bioclimatic models and data sets to project species ranges in novel environments utilizing the natural experiment in biogeography provided by Australian Acacia species. Location Australia, South Africa. Methods We built bioclimatic models for Acacia cyclops and Acacia pycnantha using two discriminatory correlative models (M axE nt and Boosted Regression Trees) and a mechanistic niche model (CLIMEX). We fitted models using two training data sets: native-range data only ('restricted') and all available global data excluding South Africa ('full'). We compared the ability of these techniques to project suitable climate for independent records of the species in South Africa. In addition, we assessed the global potential distributions of the species to projected climate change. Results All model projections assessed against their training data, the South African data and globally were statistically significant. In South Africa and globally, the additional information contained in the full data set generally improved model sensitivity, but at the expense of increased modelled prevalence, particularly in extrapolation areas for the correlative models. All models projected some climatically suitable areas in South Africa not currently occupied by the species. At the global scale, widespread and biologically unrealistic projections by the correlative models were explained by open-ended response curves, a problem which was not always addressed by broader background climate space or by the extra information in the full data set. In contrast, the global projections for CLIMEX were more conservative. Projections into 2070 indicated a polewards shift in climate suitability and a decrease in model interpolation area. Main conclusions Our results highlight the importance of carefully interpreting model projections in novel climates, particularly for correlative models. Much work is required to ensure bioclimatic models performed in a robust and ecologically plausible manner in novel climates. We explore reasons for variations between models and suggest methods and techniques for future improvements. [ABSTRACT FROM AUTHOR]

Among global changes induced by human activities, association of breakdown of geographical barriers and impoverishered biodiversity of agroecosystems may have a strong evolutionary impact on pest species. As a consequence of trade networks' expansion, secondary contacts between incipient species, if hybrid incompatibility is not yet reached, may result in hybrid swarms, even more when empty niches are available as usual in crop fields and farms. By providing important sources of genetic novelty for organisms to adapt in changing environments, hybridization may be strongly involved in the emergence of invasive populations. Because national and international trade networks offered multiple hybridization opportunities during the previous and current centuries, population structure of many pest species is expected to be the most intricate and its inference often blurred when using fast-evolving markers. Here we show that mito-nuclear sequence datasets may be the most helpful in disentangling successive layers of admixture in the composition of pest populations. As a model we used D. gallinae s. l., a mesostigmatid mite complex of two species primarily parasitizing birds, namely D. gallinae L1 and D. gallinae s. str. The latter is a pest species, considered invading layer farms in Brazil. The structure of the pest as represented by isolates from both wild and domestic birds, from European (with a focus on France), Australian and Brazilian farms, revealed past hybridization events and very recent contact between deeply divergent lineages. The role of wild birds in the dissemination of mites appears to be null in European and Australian farms, but not in Brazilian ones. In French farms, some recent secondary contact is obviously consecutive to trade flows. Scenarios of populations' history were established, showing five different combinations of more or less dramatic bottlenecks and founder events, nearly interspecific hybridizations and recent population mixing within D. gallinae s. str. [ABSTRACT FROM AUTHOR]

Background: The native rodents of Australia are commonly divided into two groups based on the time of their colonization of the Sahulian continent, which encompasses Australia, New Guinea, and the adjacent islands. The first group, the ''old endemics,'' is a diverse assemblage of 34 genera that are descended from a single colonization of the continent during the Pliocene. A second group, the ''new endemics,'' is composed of several native Rattus species that are descended from a single colonization during the Pleistocene. Finally, a third group is composed of three non-native species of Rattus and Mus introduced into Australia by humans over the last 200 years. Previous studies have claimed that the three groups differ in their reproductive rates and that this variation in rates is associated with the unique environmental conditions across Australia. We examined these hypotheses using phylogenetically controlled methods. Methodology and Results: We examined the relationship between the reproductive rates of the Australian rodents and the environmental variations across the continent, as well as the epoch of their colonization of the continent. Our results revealed no significant correlation with environmental variables but a significant association between colonization age and all the reproductive parameters examined. Discussion: Based on a larger phylogeny of the subfamily Murinae, we showed that significant differences in reproductive rates among colonization groups are shared with their closest relatives outside Sahul. Therefore, the lower reproductive rates in the old endemics are more likely to be the result of phylogenetic history and conservation of traits than an adaptation to the Australian environment. In the new endemics, we found a trend of increasing reproductive rates with diversification. We suggest that the differences in reproductive rates of the old endemic rodents and the native Rattus represent alternative adaptive strategies that have allowed them to utilize similar ecological niches across Australia. [ABSTRACT FROM AUTHOR]

Understanding the foraging ecology and diet of animals can play a crucial role in conservation of a species. This is particularly true where species are cryptic and coexist in environments where observing feeding behaviour directly is difficult. Here we present the first information on the foraging ecology of a recently identified species of dolphin (Southern Australian bottlenose dolphin (SABD)) and comparisons to the common bottlenose dolphin (CBD) in Victoria, Australia, using stable isotope analysis of teeth. Stable isotope signatures differed significantly between SABD and CBD for both δ13C (-14.4% vs. -15.5% respectively) and δ15N (15.9% vs. 15.0% respectively), suggesting that the two species forage in different areas and consume different prey. This finding supports genetic and morphological data indicating that SABD are distinct from CBD. In Victoria, the SABD is divided into two distinct populations, one in the large drowned river system of Port Phillip Bay and the other in a series of coastal lakes and lagoons called the Gippsland Lakes. Within the SABD species, population differences were apparent. The Port Phillip Bay population displayed a significantly higher δ15N than the Gippsland Lakes population (17.0% vs. 15.5%), suggesting that the Port Phillip Bay population may feed at a higher trophic level - a result which is supported by analysis of local food chains. Important future work is required to further understand the foraging ecology and diet of this newly described, endemic, and potentially endangered species of dolphin. [ABSTRACT FROM AUTHOR]

Anthropogenically-induced climate change is one of the most important global threats to biodiversity. Understanding its impact on the distribution of exotic plant species is critical for developing effective adaptation and management strategies. However, there is insufficient information currently available on the biodiversity at risk from 1) exotic plant invasions, 2) climate change, and 3) the interaction between these two major threats, to develop such strategies. We use ecological niche models as a first step to identify zones inside and outside Australian protected areas that may be most at risk from invasions of three species of Hieracium (hawkweeds) under current and future (2030 and 2070) climate scenarios, should current control and eradication methods fail. These perennial herbs are native to Europe and invasive to New Zealand and North America. Naturalised in Australia, hawkweeds threaten native tussock grasslands and the grazing industry, and have been placed on the National Alert List. Using eight ecological niche models currently available in the software package BIOMOD, we found that these species have yet to realize the extent of their climatic distribution under present day climate in Australia. As climate change accelerates, the climatic range of hawkweeds was projected to contract overall. However, much of the Australian Alps, which contain large contiguous tracts of reserves and many endemic species, will continue to retain climatically suitable areas for hawkweeds through to 2070. These results emphasise the need for ongoing monitoring as well as focused control to minimize the likelihood of hawkweeds realizing their invasive potential in protected areas and beyond. [ABSTRACT FROM AUTHOR]

The role of interspecific competition as a key factor in the ecology of natural communities where species exploit limited resources is well established, and the study of competition dynamics in snake communities has received much attention in recent years. Twenty years ago, an acclaimed review ( Toft 1985 ) suggested that snakes were atypical among vertebrates because sympatric species usually partition the food niche. Here, I review the articles published in the last two decades with the aim of finding any general geographical or guild patterns and assessing if Toft's main conclusion is still supported by new evidence. Where appropriate, I use Monte Carlo simulations to establish whether observed patterns of niche overlap are real, or if they have occurred by chance. My study shows clear congruence in the patterns of coexistence exhibited by snake communities in different regions of the world, i.e.: (1) cold regions of the northern hemisphere (high latitudes and altitudes) exhibit low species richness and a very low, or even absent, potential for interspecific competition; (2) aquatic snakes that form communities in temperate regions generally partition the food type available and exhibit a broad similarity in habitat use with subtle differences in microhabitat use; (3) terrestrial snake communities in temperate regions are very variable in terms of their coexistence dynamics and show no evidence of generalised patterns; (4) sympatric viperids in Europe, North America and, most interestingly, tropical Asia partition the available habitat but not the prey resource; (5) competition is much stronger in tropical snake communities, and the intensity of this process fluctuates throughout the year being most intense during periods of low food availability; (6) in general, tropical snakes partition the food resource (prey type and/or prey size), but when this resource is not partitioned competitive exclusion can occur. Prey resource availability is a fundamental variable for all snake communities; this is clearly documented by studies on terrestrial snakes in Australia where, due to a relative scarcity of prey availability in the field, sympatry among species is much rarer than in other continents. I conclude that, although there are several notable exceptions, Toft's main conclusion is still supported by empirical evidence. However, I disagree with Toft's conclusion that most snakes are food specialists, and I contend that interspecific competition is important in structuring many (if not most) of the snake communities around the world. [ABSTRACT FROM AUTHOR]

The potential of colonization to contribute to the spatial patterns of six common invertebrates in coralline algal turf was investigated on a rocky shore near Sydney, Australia. The species, which included two amphipods (Elasmopus warra,Hyalespp.), a small bivalve (Lasaea australis), a fly larva (Limonia marina), and two microgastropods (Amphithalamus incidataandEatoniella atropurpurea), had a range of dispersal modes (larval dispersal, crawling, swimming, rafting, and passive transport). Field sampling between May 1997 and November 1999 demonstrated that the amphipods were more abundant in low-shore areas, the fly larvae and bivalves were more abundant in mid-shore areas, and the abundances of gastropods did not vary with tidal height. Furthermore, abundances of all species varied among patches separated by tens of metres at one time or another. To test whether rates of colonization could contribute to established patterns of abundance, habitat mimics were deployed for 2-week periods. The supply of new individuals matched long-term patterns of abundance at different tidal heights forE. warraandL. marina. Colonization rates also differed among patches separated by tens of metres for three of the six species. Overall, there was little evidence to suggest that common species in coralline turf are limited by colonization on local scales, regardless of their major mode of dispersal. However, the potential for colonization to determine patterns of abundance varied from species to species. [ABSTRACT FROM AUTHOR]

AbstractBody temperatures of active lizards and their correspondence with microhabitat occupation were studied for nine species of agamid lizards in the central Australian arid zone. Thermoregulatory behaviour was also documented using several measures, such as the use of shade and perch height. The effects of thermal environment on lizard habitat occupation were hypothesized to be significant, because desert regions experience daily and seasonal extremes of temperature that are well in excess of a lizard’s preferred temperature range. All species, except Ctenophorus isolepis and Diporiphora winneckei, were found to have body temperatures that corresponded closely to ground and surface temperatures. Thermoregulatory behaviour was also found to be important throughout a lizard’s daily activity; all study species, other than Ctenophorus isolepis, were found to increase their perch height in the middle of the day. Ctenophorus isolepis was shown to be a strictly terrestrial species that uses the shade of spinifex in its thermoregulatory behaviour. Species exhibited a non-random selection of microhabitats and a preference for a particular set of thermal and structural factors. In this study, it was shown that structural factors were particularly important in microhabitat occupation. Thermal factors accounted for a smaller proportion of variance in microhabitat occupation, but still played a considerable role in the microhabitat use in central Australian agamids. [ABSTRACT FROM AUTHOR]

Anonychomyrma is a dolichoderine ant genus of cool-temperate Gondwanan origin with a current distribution that extends from the north of southern Australia into the Australasian tropics. Despite its abundance and ecological dominance, little is known of its species diversity and distribution throughout its range. Here, we describe the diversity and distribution of Anonychomyrma in the Australian Wet Tropics bioregion, where only two of the many putative species are described. We hypothesise that the genus in tropical Australia retains a preference for cool wet rainforests reminiscent of the Gondwanan forests that once dominated Australia, but now only exist in upland habitats of the Wet Tropics. Our study was based on extensive recent surveys across five subregions and along elevation and vertical (arboreal) gradients. We integrated genetic (CO1) data with morphology to recognise 22 species among our samples, 20 of which appeared to be undescribed. As predicted, diversity and endemism were concentrated in uplands above 900 m a.s.l. Distribution modelling of the nine commonest species identified maximum temperature of the warmest month, rainfall seasonality, and rainfall of the wettest month as correlates of distributional patterns across subregions. Our study supported the notion that Anonychomyrma radiated from a southern temperate origin into the tropical zone, with a preference for areas of montane rainforest that were stably cool and wet over the late quaternary. [ABSTRACT FROM AUTHOR]