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Tasmanian populations of the eastern quoll (Dasyurus viverrinus) represent the last wild stronghold of this species after its extirpation from the Australian mainland, but they have experienced declines of more than 50% over the past three decades. We investigated the feasibility of supplementing wild populations with captive-bred individuals in attempts to halt and reverse observed declines in Tasmanian populations. We released 20 captive-bred eastern quolls into an extant wild population in the Tasmanian central plateau, and monitored their short-term survival, dispersal and body condition. We recorded high initial survival and low initial dispersal of captive-bred individuals relative to previous release attempts in unfenced areas of mainland Australia. Further work to determine long-term survival of released individuals, and the genetic and population-level impacts on local populations is ongoing. Our preliminary results support the use of population supplementation as an effective conservation action, which allows for early intervention to address species declines while testing hypotheses about their underlying causes.

Context Night parrots (Pezoporus occidentalis) are one of Australia’s most endangered birds, and there is evidence suggesting feral cats (Felis catus) are a major cause of decline. However, because night parrots currently have a restricted distribution, little is known of the ecology of feral cats around their remaining populations. This limits the development of effective management strategies. Aims The aims of this study were to understand feral cat movement and habitat selection around night parrots, and to then estimate the effectiveness of possible management actions. Methods Research was conducted around the only confirmed night parrot population in eastern Australia. In 2019 and 2020, we obtained GPS data from nine feral cats, and used step selection functions to assess preferred habitats. Management options were then simulated based on cat movement data, including altering trap numbers and layout, and changing routes for night spotlight shooting (using existing roads, random walking or creating new roads in preferred habitats). Key results Feral cats preferred alluvial and riparian habitats and avoided rocky woodlands and roads. Simulated control efforts were more successful if traps are placed at ‘pinch points’ where drainage lines converged, and if new roads were created near to creek lines and alluvial habitats. Conclusions Feral cats move around the last known population of night parrots in eastern Australia, travelling through and using many shared habitats. Targeting creek lines and alluvial areas in cat control operations would improve effectiveness and potentially reduce predation impacts on night parrots. Implications Conservation of endangered birds like night parrots can be enhanced through understanding the ecology of threats such as feral cats to develop locally tailored control operations.

Predator diet can provide important data to inform management actions as well as an enhanced understanding of the fauna of a region. The diet of dingo (Canis lupus dingo), feral cat (Felis catus) and eastern barn owl (Tyto delicatula) were compared using scat, stomach and pellets from a significant conservation reserve in southwest Queensland. Dingo diet was dominated by macropods, while the diet of feral cat and barn owl was dominated by small mammals. We found no remains of threatened species but recommend continued monitoring of predator diet as a tool to assist management.

Localities at the intersection of bioclimatic zones can produce interesting bird-community assemblages. Edgbaston Reserve, in central-western Queensland, known for the high biodiversity of its artesian springs complex, sits within the intersection of the Torresian, Bassian and Eyrean bioclimatic zones and straddles the intersection of two bioregions on the western edge of the Great Dividing Range. Here we present bird records accumulated through standardised surveys and opportunistic observations. A total of 143 species of birds was detected on Edgbaston Reserve. From these data we report on notable species recorded and the significance of the avifauna community found on this Reserve. In addition to Edgbaston conserving artesian-spring habitat and threatened aquatic species, we highlight the importance of this Reserve for the preservation of woodland and arid birds.

The birds of arid environments often exhibit nomadism, seasonal breeding and population fluctuations that respond to highly variable weather patterns. In this study we present data from a baseline bird survey in Bush Heritage Australia’s Pullen Pullen Reserve in south-western Queensland. We conducted seasonal surveys (October–November 2018, May 2019) in 40 sites representing Spinifex (Triodia spp.) grasslands, a complex of Mitchell Astrebla spp./chenopod grasslands and Georgina Gidgee Acacia georginae riparian woodlands, using a standardised 2-ha census. A total of 85 species was recorded in the standardised sites, as well as an additional 16 species recorded opportunistically. Twenty-six species (31%), many of which were nomadic, were recorded from only one of the surveys. Bird abundance and species richness were highest in the post-wet-season survey (May 2018), and there was strong variation in the composition of the bird species between the three habitats surveyed. These data provide a baseline to continue monitoring and to understand the resident and more peripatetic elements of this arid bird community, which should be surveyed regularly to investigate the role of changing management and the long-term influence of global environmental change.

Arid and desert landscapes are characterised as boom-bust systems, and sometimes its fauna can remain cryptic or hidden. This short paper reports the results of baseline monitoring of the terrestrial fauna in the Bush Heritage Pullen Pullen reserve in south-west Queensland, most notable for the presence of the night parrot Pezoporus occidentalis. We conducted two fauna surveys over 22 sites representing Spinifex grasslands, and Mitchell and Chenopod grassland habitats in 2018 and 2019, using pitfall, funnel and Elliott traps, and active searching. A total of eight mammal and 28 reptile species comprising 730 records were documented, as well as eight additional incidental species. Frequently recorded species were Ctentous lateralis, Ctenotus pantherinus, Gehyra versicolor, Tachyglossus aculeatus, Sminthopsis macroura, Pseudomys desertor. Fourteen of the species recorded were highly variable in abundance from one survey to the next. The fauna of the Spinifex grasslands, and Mitchell and Chenopod grassland sites was compositionally very different, and the extent of ground cover or Triodia in the surrounding landscape predicted the abundance of some mammals (i.e. Pseudomys desertor) and reptiles (Delma nasuta, Ctenotus pulchellus, Cyclodomorphus melanops). These data provide a baseline for future monitoring on this important reserve, and an opportunity to enhance or increase the survey scope via additional sites and a future more adaptive management and question-driven approach.

The eastern barn owl (Tyto delicatula) is a significant native predator of small mammals in Australia. Regurgitated pellets can provide important data on species presence, current or historical changes in mammal fauna over time, or data on cryptic or threatened species. We collected 125 pellets from Cravens Peak reserve, Simpson Desert, Queensland, and examined the contents, including changes in diet over time (using age of pellet as a proxy) and the relative importance of different prey. In total, 642 unique prey items were recorded, 92% of which were mammals. Small rodents were the dominant prey – Mus musculus and Pseudomys hermannsburgensis, and the presence of Notomys cf. fuscus, Pseudantechinus cf. mimulus and Dasycercus blythi were all significant, being range extensions. Such data add to more traditional or novel techniques to record community changes over time.

Nest predation is considered a major cause of population decline for the Endangered Alwal Psephotellus chrysopterygius (Golden-shouldered parrot) in Cape York Peninsula, Australia. Camera-traps wer...

Tasmanian populations of the eastern quoll Dasyurus viverrinus, which represent the last wild stronghold of this species after its extirpation from the Australian mainland, have experienced declines of more than 50% over the past three decades. In this pilot study, we investigate the feasibility of supplementing wild populations with captive-bred individuals to attempt to reverse observed declines. Our results are encouraging, in that we recorded high initial survival and low initial dispersal of captive-bred individuals relative to previous release attempts in mainland Australia. Further work is ongoing to determine long-term survival of released individuals and the genetic and population-level impacts on local populations. Our preliminary results support the use of population supplementation as an effective conservation action, which allows for early intervention to address species declines while simultaneously testing hypotheses about their underlying causes.

Successful conservation of threatened species requires judicious allocation of limited resources. The threatened Black-throated Finch southern subspecies (Poephila cincta cincta), endemic to north-...

It may be possible to avert threatened species declines by protecting refuges that promote species persistence during times of stress. To do this, we need to know where refuges are located, and when and which management actions are required to preserve, enhance or replicate them. Here we use a niche-based perspective to characterise refuges that are either fixed or shifting in location over ecological time scales (hours to centuries). We synthesise current knowledge of the role of fixed and shifting refuges, using threatened species examples where possible, and examine their relationships with stressors including drought, fire, introduced species, disease, and their interactions. Refuges often provide greater cover, water, food availability or protection from predators than other areas within the same landscapes. In many cases, landscape features provide refuge, but refuges can also arise through dynamic and shifting species interactions (e.g., mesopredator suppression). Elucidating the mechanisms by which species benefit from refuges can help guide the creation of new or artificial refuges. Importantly, we also need to recognise when refuges alone are insufficient to halt the decline of species, and where more intensive conservation intervention may be required. We argue that understanding the role of ecological refuges is an important part of strategies to stem further global biodiversity loss.

The Einasleigh Uplands bioregion of central north Queensland, Australia, harbours a unique suite of reptiles that have begun to receive significant attention in the last 20 years. This has resulted in a number of new reptile species being described, and recognition that others await description. We describe a new species of Lucasium Wermuth, 1965 from the western Einasleigh Uplands. Lucasium iris sp. nov. is genetically distinct and morphologically diagnosable from all congeners by its large size, long and narrow tail, nares in contact with rostral scale, homogeneous body scales, distinct vertebral stripe, and paired, enlarged, apical subdigital lamellae. It is known from low rocky hills in a localised area of the Gregory Range, has the most restricted known distribution of any Lucasium, and is the only Lucasium endemic to Queensland. The new species appears most closely related to L. steindachneri (Boulenger, 1885), based on mitochondrial DNA sequences, but has a colour-pattern more similar to L. immaculatum Storr, 1988. All three of these species occur in the Einasleigh Uplands, but only L. steindachneri is known to occur in sympatry with L. iris sp. nov. In addition to the description of the new species, we present records of Lucasium immaculatum from the Einasleigh Uplands, which represent a significant known range extension.

In addition to feeding on animal remains, many scavengers also function as predators. Carcasses may therefore affect local animal communities by attracting facultative scavengers and increasing predation risk for other species in the vicinity of the carcasses. This risk may be elevated in low productivity environments, especially where humans increase carcass production and where facultative scavengers include invasive species. In June and October 2018, we monitored experimentally placed red kangaroo (Osphranter rufus) carcasses and artificial bird nests in two different habitats in the Simpson Desert, Australia, to identify the nest predators attracted to the carcasses, and to determine how carcasses affect overall and predator-specific nest predation. We modelled our nests to approximate those of the ground nesting little buttonquail (Turnix velox) and the endangered night parrot (Pezoporus occidentalis). Native Corvus spp. and then invasive red foxes (Vulpes vulpes) were the top carcass visitors and nest egg predators. Carcass presence and open habitat increased overall nest predation and fewer artificial parrot nest eggs were depredated compared to those of quail. Open habitat and carcass presence only increased predator-specific nest predation by foxes, but corvid nest predation was highest in June 2018, and for the artificial quail nest types. Foxes were the main predator of eggs from night parrot nests. Our study shows that carcass provisioning by humans may have indirect, deleterious effects on ground nesting birds, and indicates that foxes might pose a greater threat to night parrot populations than previously recognised.

South-western Queensland supports a suite of threatened native species, including Night Parrots. We investigated why this species has persisted in the region and discovered low prevalence of the typical factors that are thought to explain fauna attrition elsewhere in central Australia. Foxes appear to be completely absent. Feral cats were recorded relatively infrequently and showed a significant preference for habitats less commonly used by Night Parrots, a partition that may be driven by the presence of dogs that were detected twice as frequently as cats. Our study area has had a long history of moderate grazing pressure, which is concentrated mostly in productive alluvial habitats. We detected very few herbivores, and dog scat analyses suggest that macropod populations are regulated by predation. Archival imagery shows that large fires are not a feature of this landscape, resulting in the long-term, stable availability of patchy Triodia habitats separated by natural no-fuel areas. Based on these empirical data, we postulate that low non-native predator pressure, long-term stable availability of Triodia cover and a productive landscape that has had only moderate grazing pressure are the interacting factors that may explain why Night Parrots have persisted in south-western Queensland. We present practical management actions that could enhance the suitability of this landscape for Night Parrots.

Habitat and landscape gradients can provide insight on how vegetation pattern influence the composition and species turnover in birds. Gradients on mountainsides are particularly suitable as the vegetation can be distinctly stratified. On the western fall of the Australian wet tropics, the vegetation traverses through tropical savanna into tropical rainforest over a relatively short distance. We investigated bird richness and abundance in this transition. Seventeen sites were sampled from lowland (350 m) to upland (1000 m) locations, comprising six zones. Birds were sampled four times between 2006–2007. 125 species of birds representing 38 families were recorded. The pattern of abundance and richness along this gradient was characterised by second-order polynomial relationships. The nadir was where change in vegetation was most rapid; low open woodlands to dry open forest, between 500 and 800 m. We conclude that the avifauna assemblage we recorded along the gradient represents predominantly a woo...

The critically endangered golden sun-moth Synemon plana occurs in urban fringe areas of southeastern Australia that are currently experiencing rapid and extensive development. The urban fringe is a complex and uncertain environment in which to manage threatened species with the intersection of fragmented natural habitats, built environments and human populations generating novel, poorly understood interactions. In this context, management frameworks must incorporate ecological processes as well as social considerations. Here, we explore how biodiversity sensitive urban design might improve the fate of the golden sun-moth, and threatened species generally, in urban fringe environments. We: (i) developed an expert-informed Bayesian Belief Network model that synthesizes the current understanding of key determinants of golden sun-moth population viability at sites experiencing urbanizing pressure; (ii) quantified the nature and strength of cause-effect relationships between these factors using expert knowledge; and (iii) used the model to assess expectations of moth population viability in response to different combinations of management actions. We predict that adult survival, bare ground cover and cover of resource plants are the most important variables affecting the viability of golden sun-moth populations. We also demonstrate the potential for biodiversity sensitive urban design as a complementary measure to conventional management for this species. Our findings highlight how expert knowledge may be a valuable component of conservation management, especially in addressing uncertainty around conservation decisions when empirical data are lacking, and how structured expert judgements become critical in supporting decisions that may help ameliorate extinction risks faced by threatened species in urban environments.

Summary The effective control of highly invasive weeds in Australia is an important conservation management action. In this study, we monitored the outcome of herbicide control on high-threat weeds in the wet forests of the Central Highlands of Victoria. Twenty-two control (no weed control) and 32 treatment (weed control) plots were surveyed annually over 24 months. Initial results show that weed cover and frequency decreased substantially in response to weed control; however, it is too early to determine the response of native species. We recommend that herbicide control and the associated monitoring programme be continued, and depending on the outcomes, data should be used to develop a more integrated management strategy.

Native grasslands, and the fauna that inhabit them, are globally some of the most threatened ecosystems and organisms. Knowledge of the relative importance of climate, landscape context and site-based resources for local insect populations is critical for the restoration and conservation of these communities. We investigated the site and landscape-scale best predictors of occurrence and abundance over three consecutive years of sampling, for the critically endangered golden sun moth Synemon plana in south-eastern Australia. We found eight vegetation factors to be significantly associated with golden sun moth occurrence using data from combined survey data and data for each year alone; we identified just three common factors from year to year. Modelling indicated that Austrostipa and Rytidosperma species richness was the most consistent parameter, but for each year alone, there was a combination of aspect, landscape position and Austrostipa and Rytidosperma species richness. Our study shows that environmental characteristics where golden sun moth occur are relatively predictable over multiple years. This information can be used to protect sites where monitoring of extant populations is yet to occur, predict the location of new populations in the region, and restore adjacent habitat that is suitable but degraded.

Carbon farming initiatives have rapidly developed in recent years, influencing broad scale changes to land management regimes. In the open carbon market a premium can be secured if additional benefits, such as biodiversity conservation or social advancement, can be quantified. In Australia, there is an accepted method for carbon abatement that requires shifting fire frequency from predominantly late, defined as fires occurring after August 1, to early dry-season fires or by reducing overall fire frequency. There is an assumption and some evidence that this might accrue co-benefits for biodiversity. We tested this assumption by comparing terrestrial vertebrate biodiversity patterns (richness and abundance of reptiles, birds and mammals) against increasing fire frequency in the early and late dry-season at the same spatial resolution as the fire management for emission abatement method. We systematically sampled 202 sites on Cape York Peninsula, and examined the relationship between vertebrate fauna, fire and environmental metrics. We found that within the approved vegetation type, open woodlands in tropical savanna woodland, early and late dry-season fire frequency had the same weak linear relationship with only some elements of the observed fauna. Additionally, the response of each taxa to fire frequency were different across broad vegetation structural categories, suggesting that a more nuanced species-specific monitoring approach is required to expose links between savanna burning for carbon abatement and burning for biodiversity benefit.

Following the establishment of a conservation reserve, changes in ground stratum vegetation following removal of cattle were examined in a northern Australian savanna over a 10-year period. The floristic composition of 40 vegetation plots in lowland savannas were surveyed shortly after acquisition of the property, and then surveyed twice in the following 10 years after cattle removal. Some notable ecosystem-transforming introduced species (weeds) such as Themeda quadrivalvis remained relatively stable, whereas the pasture legume Stylosanthes scabra increased in cover. The species richness of both native and introduced plants increased. Various plant functional groups changed in relative cover, with a decline in relatively unpalatable grasses and a corresponding increase in palatable grasses, responses that are consistent with recovery from grazing pressure. Our results show that removal of cattle in highly disturbed savanna ecosystems can have both positive and negative results for native ground stratum vegetation in the first decade of recovery.

Assessments of species vulnerability to climate change should increase the effectiveness of interventions in the current decline in biodiversity. Species vulnerability to climate change is a consequence of their sensitivity and adaptive capacity, in combination with their exposure to climate change. We apply a vulnerability assessment framework to 243 bird species inhabiting the tropical savannas of northern Australia. We build on previous vulnerability studies by including detailed data for variables relating to species sensitivity to change (relative abundance, clutch size, sensitivity to fire and distribution area), species adaptive capacity (movement behaviour and dietary breadth) and proportional changes predicted for their geographic range (i.e. exposure to climate change). These are integrated to provide a ranking of vulnerability. Our analysis found that birds of Australian tropical savannas cluster together with high sensitivity, with a few wide-ranging increasing species with very low sensitivity. Australian tropical savanna birds have a range of adaptive capacities, and the impact of climate change on these species is predicted to be substantial. Two already endangered species are among the most vulnerable. Species largely restricted to Cape York Peninsula (a geographically distinct region) had the greatest overall vulnerability; these species were, in general, sensitive due to small distributions, sensitivity to fire frequency and had a lower capacity for dispersal. It will be important for the future of Australian tropical savanna birds to mitigate ecological threats and maintain extensive areas of suitable habitat to facilitate species dispersal.

In Australia, the role of noisy miners Manorina melanocephala in biotic homogenization of the avifauna has been well established in modified landscapes, and is listed as a threatening process under national conservation legislation. However, less is known about the effect of the congeneric and more widely distributed yellow-throated miner, M. flavigula. In this paper we investigate the relative roles of habitat loss and increased dominance by the yellow-throated miner in avian homogenization and species functional group decline. We examined bird community data collected from 368 woodland sites across three bioregions. For each site there was a local and a landscape scale measure of remnant vegetation cover. We used both multivariate and regression analysis to test the relative influence of yellow-throated miner abundance and vegetation on bird community composition. There was clear compositional change and homogenization of the avifauna where yellow-throated miners were present and vegetation cover was low. The abundance of 40 bird species was predicted by combinations of vegetation cover or yellow-throated miner abundance, and 31 of these regressions included the term yellow-throated miner. Of these, there was a negative relationship with 23 species, and 19 of these were insectivores or nectarivores. We postulate that the combination of clearing and yellow-throated miner abundance can interact to disrupt the ecological function of woodlands, by the depletion of insect- and nectar-feeding species and the disturbance to mixed feeding flocks. We propose future research objectives that include a continental-scale analysis of the determinants of yellow-throated miner overabundance, the numerical and geographical thresholds of their potential impacts, and the ecological consequences on both avifauna and the woodlands they inhabit.

Aim Strongly interacting species have disproportionately large ecological effects relative to their abundances or biomass. We previously developed two conceptual models that described how one such strong interactor, the Australian bird the noisy miner Manorina melanocephala : (1) establishes resident high-density and hyperaggressive colonies and (2) in doing so, affects other biota and ecosystem processes. Here, we evaluate parts of those models relating to noisy miner habitat preferences and effects on bird assemblages using data from across the geographical range of the miner. Location Eastern Australia. Methods Avian-assemblage data were compiled for 2 128 survey transects (distributed over > 1.3 × 10 6 km 2 ) and were linked to variables reflecting productivity, local habitat structure and landscape context. Predictors were chosen based on the models, although detailed data for some variables were unavailable at such large scales. We used hierarchical Bayesian models that included observation models to account for different survey effort coupled with potentially nonlinear, spatially-explicit process models. Conclusions Noisy miner densities increased with proximity to forest edges (higher densities on forest edges and open sites), in low rainfall areas, and in vegetation dominated by trees with blade-shaped rather than needle-shaped leaves. The presence of noisy miners at even relatively small densities (> 0.6 individuals ha −1 ) depressed both species richness and the abundances of smaller ( 63 g) bird species. In areas with higher mean rainfall, the associations between noisy miners and small- and large-bird species were more negative and less positive, respectively.

In this study we examined the spatial and temporal variation in a population of the critically endangered golden sun moth Synemon plana over four years in a conservation reserve in south-eastern Australia. We found golden sun moth spatial distribution and abundance dramatically declined from a peak in extent and abundance from 2008–2009 to 2011–2012 due to a shift from drought to above average rainfall. Autoregressive correlative models indicated that a northerly aspect and landscape position were key predictors of abundance over time, and golden sun moth distribution shifted from wet to dry locations in the landscape. We conclude that: our data provide a counterpoint to conclusions that golden sun moth has been known to persist in very small areas and suggest that distribution can change quite markedly (from large connected populations to small patches) at a local scale, and this will be due to dispersal and survivorship; the variability in the data may have implications for adequate detection of the species over time, especially when populations have contracted and species have a naturally restricted activity and breeding period; and long-term weather patterns and landscape configuration (aspect, wet or dry position) interact to significantly affect local distribution and abundance over time. This has implications for the species under global change; increased variability in rainfall, temperature, productivity and exotic pasture growth may all alter and interact to either reduce or enhance persistence of golden sun moth populations over time.

Summary The protection and management of grasslands is a priority to conserve biodiversity, particularly in fragmented landscapes subject to human-induced disturbance. We examined the success of salvage and reinstatement of multiple 90 m2 slabs of modified temperate grassland in a pipeline construction corridor in south-eastern Australia and compared it with a reinstated topsoil treatment (i.e. standard pipeline reinstatement practice) and an undisturbed control. Thirty-six plots (each 9 × 10 m) representing the three treatments were monitored across six locations, pre- and postconstruction every 3 months for 2 years. We sampled 18 vegetation/habitat variables to examine the effect of treatments over time. Introduced grass cover was consistently higher than native grasses for both treatments, and the cover of introduced grasses increased over time in both treatments. Conversely, control plots had considerably higher native grass cover than the slab and reinstated topsoil treatments. Native species richness was not negatively affected by the slab reinstatement process. Our results suggest that in this instance, slab replacement was an ineffective way to reinstate native grasslands, as it appeared to confer minimal benefit when compared to the standard practice of reinstating topsoil. This was most likely due to the high degree of disturbance to slabs during the reinstatement process.

Aim We explored whether one native bird (the yellow-throated miner Manorina flavigula) greatly affected the composition of avifaunas in > 500,000 km2 in northern Australia. Location Rangelands of north-eastern Australia Methods Repeated avian surveys were conducted in 368 locations, for which in-site vegetation and landscape-contextual measurements were made. Hierarchical Bayesian models were used to determine whether avian assemblages were affected by variation in abundances of the yellow-throated miner. Results Variation in the abundances of the yellow-throated miner appeared to be governed largely by vegetation cover in surrounding landscapes. Summed abundances and richness of birds less massive than the yellow-throated miner ( 53 g) bird could not explain the patterns of variation in small-bodied species as well as the yellow-throated miner. There were no relationships between abundances and richness of larger species and abundances of the yellow-throated miner. Main conclusions The genus Manorina appears to be a competitive despot insofar as species smaller than it are concerned. There now is strong evidence that the local composition of avifaunas over much of a continent is controlled by the indiscriminate aggression of a colonial genus. Many of the existing ideas in community ecology that have been proffered for explaining the composition of vertebrate assemblages are inadequate for these assemblages given the profound influence of species of the genus Manorina. The mooted agricultural expansion of development in northern Australia almost certainly would favour the spread of the yellow-throated miner and probably will depress the occurrence and abundances of small-bodied bird species.

Pitfall trapping is a long established method for trapping terrestrial vertebrates globally. Many variations in bucket and drift fence arrays are used. Recent survey guidelines have been published for Queensland and the Northern Territory. In Queensland a “T” pattern is recommended, and we used data collected over five years to assess whether the use of this array, with the addition of a central bucket (Pit B), results in more captures, particularly in the central bucket. A total of 263 sites representing 1052 bucket samples were examined and the differences in capture abundance in bucket location was tested using analysis of variance. Pitfall bucket location significantly affected the captures of Dasyuridae, Muridae, Agamidae, Pygopodidae, Scincidae (P

The recent commentary by Woinarski (2014, Global Ecology and Biogeography, doi: 10.1111/geb.12165) disagreed with our conclusions on the correlates of decline in the marsupials of tropical Australia (Fisher et al., 2014, Global Ecology and Biogeography, 23, 181–190). We compared traits of species that were associated with range decline in southern and northern Australia. We found that habitat structure, climate and body size were correlated with range decline. In the north, declines of marsupials were most severe in savanna with moderate rainfall. In the south, the ranges of species in open habitat with very low rainfall have declined most. Also, the association between range decline and body mass differed between north and south: this is the main concern of Woinarski, who further disagreed with our choice of the Tropic of Capricorn as a boundary between north and south, our omission of rodents, how to treat timing of extinctions, and our inference that cats are major drivers of decline. We address these concerns in this response.

Aim A third of all modern (after 1500) mammal extinctions (24/77) are Australian species. These extinctions have been restricted to southern Australia, predominantly in species of ‘critical weight range’ (35–5500 g) in drier climate zones. Introduced red foxes (Vulpes vulpes) that prey on species in this range are often blamed. A new wave of declines is now affecting a globally significant proportion of marsupial species (19 species) in the fox-free northern tropics. We aim to test plausible causes of recent declines in range and determine if mechanisms differ between current tropical declines and past declines, which were in southern (nontropical) regions. Location Australian continent Methods We used multiple regression and random forest models to analyse traits that were associated with declines in species range, and compare variables associated with past extinctions in the southern zones with current tropical (northern) declines. Results The same two key variables, body mass and habitat structure, were associated with proportion-of-decline in range throughout the continent, but the form of relationships differs with latitude. In the south, medium-sized species in open habitats of lower rainfall were most likely to decline. In the tropics, small species that occupy open vegetation with moderate rainfall (savanna) are now experiencing the most severe declines. Throughout the continent, large-bodied species and those in structurally complex habitats (rainforest) are secure. Main conclusions Our results indicate that there is no mid-sized ‘critical weight range’ in the north. Because foxes are absent from the tropics, we suggest that northern Australian marsupial declines are associated with predation by feral cats (Felis catus) exacerbated by reduced ground level vegetation in non-rainforest habitats. To test this, we recommend experiments to remove cats from some locations where tropical mammals are threatened. Our results show that comparative analysis can help to diagnose potential causes of multi-species decline.

Ecological monitoring is important for tracking trends in species and ecosystems over time and is the basis of conservation planning and government policy. Given there are increasing constraints on funding opportunities for conservation research there need to be simple approaches to assess the costs and effectiveness of surveys that highlight where methods can be refocussed to address changing management aims. In this study we use data from a vertebrate fauna monitoring program to assess the extent to which the sampling has been effective in recording the total estimated vertebrate species richness, identify which classes, families or functional groups of birds, mammals and reptiles have been under sampled by existing methods and which of the survey methods used were most cost effective. We compiled data collected over six surveys conducted over five years on a conservation reserve in northern Australia as a case study. We used rarefaction curves to examine the rate of species accumulation and sampling adequacy for 15 fauna functional groups representing bird, mammal and reptile taxa. We also compared the cost effectiveness using the relative dollar cost for six survey methods including both observational (active search, bird counts) and trapping (cage, box, funnel and pitfall traps) techniques. In our case study, despite six repeated surveys, with a total estimated cost in excess of $500 000, sampling for six of the 15 targeted fauna groups was insufficient. Multiple survey methods are required to sample taxa such as reptiles and small mammals. Costs per methods were approximately equal when comparing different techniques such as pitfall, cage, Elliott and funnel traps. This study demonstrates that it is straightforward to use simple metrics of survey success to guide, refine and improve monitoring programs.

Species are largely predicted to shift poleward as global temperatures increase, with this fingerprint of climate change being already observed across a range of taxonomic groups and, mostly temperate, geographic locations¹⁻⁵. However, the assumption of uni-directional distribution shifts does not account for complex interactions among temperature, precipitation and species-specific tolerances⁶, all of which shape the direction and magnitude of changes in a species' climatic niche. We analysed 60 years of past climate change on the Australian continent, assessing the velocity of changes in temperature and precipitation, as well as changes in climatic niche space for 464 Australian birds. We show large magnitude and rapid rates of change in Australian climate over the past 60 years resulting in high-velocity and multi-directional, including equatorial, shifts in suitable climatic space for birds (ranging from 0.1 to 7.6 km yr⁻¹, mean 1.27 km yr⁻¹). Overall, if measured only in terms of poleward distribution shifts, the fingerprint of climate change is underestimated by an average of 26% in temperate regions of the continent and by an average of 95% in tropical regions. We suggest that the velocity of movement required by Australian species to track their climatic niche may be much faster than previously thought and that the interaction between temperature and precipitation changes will result in multi-directional distribution shifts globally.

The tropical savanna of northern Australia is extensive and relatively homogenous compared to the open woodlands of temperate Australia. The avifauna of this biome is unevenly dispersed in the landscape. A standard count method for birds using a timed search along a 100-m transect with eight repeated counts per site over 4 days, has been used extensively over the past decade or more in these savannas, but its effectiveness has never been critically examined. We used data collected from across northern Queensland from 2004 to 2010, comprising 502 single-survey sites (each transect counted eight times) and 60 sites re-sampled four times from 2004 to 2008, to examine species records and accumulation of species over time with respect to time of day, increasing number of repeat counts(from 2 to 32 counts), species turnover, vegetation density effects and distance to first observation. Over 70% of the species in tropical savannas were easily observed and for 93% of the species vegetation structure did not alter detectability. Richness and abundance did not vary significantly across the day. We found that repeated sampling over multiple days, and at different times of the day, provides the best estimate of species richness at a site, and improved detectability.

The study of the ecology of species assemblages provides information on the function and resilience of ecosystems and helps predict the response of species to environmental change. Mixed-species flocks are a particular mode of avian assemblage and are suggested to have benefits for foraging and predator vigilance. In this study we examine for the first time the composition of mixed-species flocks in Australian savannas using data from 335 mixed-species flocks recorded across northern Queensland. A total of 122 species, both passerines and non-passerines, were observed in flocks. Individual flocks comprised 2–21 species and 2–237 individuals, with small, insectivorous birds dominant. Although flock composition was largely undifferentiated, six broad groups of mixed-species flocks were identified, their similarity driven by a few key species. Our study found that mixed-species flocks are a common component of the tropical savannas and are similar in individual bird abundance and richness compared with studies in other biomes. One important next step is to examine the relationship of mixed flocks to the entire species pool, and their ecological significance within tropical savannas.

The domestic cat Felis catus is distributed worldwide and has had a long historical relationship with humans. In some regions, such as Australia, it has become feral and a significant predator of native wildlife. A key component of quantifying and managing the conservation threat of introduced predators is an understanding of exactly what size and taxa of prey species are consumed, and whether there is a high degree of selectivity in the diet. A total of 169 cat stomachs were collected from north-eastern Australia, and their contents examined in relation to prey size, the body size of cats and selectivity using Jacob’s index. I found that F. catus contains a large amount of prey per cat (~200 g), mammals are the dominant prey item by mass, and feral cats predation was selective of small mammals (

Tropical savanna environments are characterised by annual and decadal patterns of resource change, which can affect the patterning of mobile fauna such as birds. In this study, we sampled 60 sites in northern Queensland, four times from 2004 to 2008. We investigated how the bird richness and abundance, and species turnover changed over the sample years and how this differed with vegetation structure. The mean abundance per site was highest in 2005 (92.1 ± 12.0 individuals ha–1) and lowest in 2008 (46.6 ± 3.3), whereas species richness per site was highest in 2004 (19.6 ± 0.9 species ha–1) and lowest again in 2008 (14.7 ± 0.8). Nine species were most abundant in 2004 coincident with extremely high rainfall preceding the survey in that year. Species turnover increased across all sites from 2004 to 2008 and the abundance of 13 species was best accounted for by differences in vegetation structure. Our study demonstrates that local bird communities in the semi-arid fringe of savannas can change rapidly, and mostly where vegetation is modified. This suggests that increased land-use and climate change in northern Australia could have significant effects on the avifauna over fairly short periods.

The introduction of domestic cattle into systems that have had little historical grazing by large herbivores, such as the case in Australia, can lead to both direct and indirect changes in native flora and fauna. In this study, we investigate the differences in native mammal abundance between pastoral land managed for cattle production and conservation land in Australian tropical savannas. We systematically sampled 68 sites for mammals in north-eastern Queensland representing the two land tenures, which represent land with introduced stock and native herbivores present, and land where only native herbivores occur. We recorded 17 species of mammals representing five families and two functional groups (small mammals and macropods). Generalized linear mixed effects models identified that there was a significant positive relationship between increasing total ground cover and small mammal abundance and also the abundance of two species, Pseudomys desertor and P. gracilicaudatus. We recorded a reduction in abundance on pastoral land for macropods and small mammals, and four species, M. robustus, M. rufus, Leggadina lakedownensis, P. gracilicaudatus. Total ground cover and perennial grass cover was lower on pastoral land. Small mammal abundance on pastoral land was less even with increasing ground cover. Our results suggest that on pastoral land, native mammal abundance is affected and this has some relationship to ground cover changes. We recognize that there are other confounding management differences between pastoral and conservation lands such fire use, dingo baiting, and the manner of weed invasion and control that could influence mammal pattern. We conclude that conservation strategies for mammals in Australia’s tropical savannas need to include a variety of land management schemes and tenures including land free from grazing by domestic livestock.

Overabundant native species can have a significant cascading effect on other components of wildlife, and those that deplete other species, often promoted by anthropogenic change to vegetation cover and habitat, are called reverse keystone species. Birds in the genus Manorina are widely reported as being such species, and in highly disturbed or fragmented environments, and some intact environments, noisy miners Manorina melanocephala can have a strong negative effect on small passerine species via hyper-aggressive mobbing. The tropical savannas of northern Australia consist of largely unmodified woodlands, and two species of Manorina occur naturally in this region: the noisy miner and the yellow-throated miner Manorina flavigula. Therefore, what effect do these species have on bird assemblage in predominantly continuous habitats, relative to other typical determinants of avifauna assemblage such as vegetation structure? We used data collected from bird surveys at 511 sites across northern Queensland (179 noisy miner M. melanocephala sites, 332 yellow-throated miner M. flavigula sites) between 1998 and 2010. We examined the variation in bird composition at each site due to increasing abundance of Manorina spp. using uni- and multivariate techniques. We found total bird richness was significantly lower in sites where noisy and yellow-throated miner abundances were highest, and passerine species seemed most affected. For species, 45 species varied significantly in abundance with increasing miner numbers, and the overall effect of yellow-throated miners on other birds seemed more pronounced. However, vegetation structure was generally an equal or more important predictor of avifauna richness and abundance. We conclude that despite the superficially intact nature of northern Australian woodlands, pastoral intensification or poor land management might create disturbances that facilitate increases in the abundance of Manorina, causing localized overabundance and a compounding negative effect on other native bird species.

This paper reports the results of dry and wet season systematic terrestrial vertebrate fauna surveys carried out on Blackbraes, a National Park in the Einasleigh Uplands bioregion, North Queensland. It quantifies, for the first time, the biodiversity values of the highest altitude upland area in the Australian tropical savanna. Nine species, including two mammals and seven reptiles, were recorded at the limits of their known range, or in seemingly disjunct populations. Patterns of fauna assemblage in relation to underlying geology and associated habitat variables were investigated and several strong relationships emerged. Temporal patterns in the observed fauna were investigated and 20 species (15 birds, 5 reptiles) were found to be more numerous in different seasons (wet and dry). The avifauna recorded was consistent with much of Australia's tropical savanna, but the reptile and mammal assemblages were distinct, rich and unusual, with exceptionally high abundances, particularly of some arboreal mammals. ...

Developing robust species distribution models is important as model outputs are increasingly being incorporated into conservation policy and management decisions. A largely overlooked component of model assessment and refinement is whether to include historic species occurrence data in distribution models to increase the data sample size. Data of different temporal provenance often differ in spatial accuracy and precision. We test the effect of inclusion of historic coarse-resolution occurrence data on distribution model outputs for 187 species of birds in Australian tropical savannas. Models using only recent (after 1990), fine-resolution data had significantly higher model performance scores measured with area under the receiver operating characteristic curve (AUC) than models incorporating both fine- and coarse-resolution data. The drop in AUC score is positively correlated with the total area predicted to be suitable for the species (R2 = 0.163–0.187, depending on the environmental predictors in the model), as coarser data generally leads to greater predicted areas. The remaining unexplained variation is likely to be due to the covariate errors resulting from resolution mismatch between species records and environmental predictors. We conclude that decisions regarding data use in species distribution models must be conscious of the variation in predictions that mixed-scale datasets might cause.

Aim: Fire is a major driver of ecosystem structure and process, and shifts in fire regimes are implicated in the decline of many species. Shifting fire regimes have been documented around the world, and fire frequency and extent is predicted to increase in many areas because of changes in both climate and land management. Here, we evaluate how predicted increases in fire frequency are likely to impact on species distributions. Location: The tropical savannas of northern Australia. Methods: We developed distribution models for 44 bird species using the modelling algorithm Maxent. Our models incorporated bird locality records and environmental variables including climate, total fire frequency and the subset of fire frequency occurring late in the dry season. We investigated the effect of increasing total fire frequency and increasing fire late in the dry season, on species distributions by projecting species model algorithms onto scenarios of incrementally increased total fire frequency. Results: The probability of presence for most species was higher when fire frequency late in the dry season was low. Species showed a mixed response to an overall increase in total fire frequency, with one-third predicted to increase in distribution. However, almost all species (98%) showed a decrease in predicted range with increased late-dry season fire, and species distribution area was generally negatively correlated with an increase in late-dry season fire. Main conclusions: Our study highlighted the array of responses of species to increasing fire frequency and suggested that increased fire frequency late in the dry season is detrimental to most savanna-restricted bird species. The understanding of individual species' preferences for particular fire frequencies is important for informed conservation planning.

An essential component of conservation science is repeated surveys over time to monitor species that might be responding to local factors, such as land management, or more broadly to global change. A systematic survey of the avifauna of Cape York Peninsula was conducted in the late 1990s and early 2000s providing an ideal basal dataset for measuring change in the avifauna. A subset (n >600) of these sites, primarily within savanna landscapes, was selected for re-survey in 2008 to investigate changes in bird communities on Cape York Peninsula. Changes in mean species richness varied across the study area (decreases in 59 grid cells and increases in 43) with no apparent pattern. Significant change in reporting rates was recorded in 30 species. Four sedentary and highly detectable species declined (Bar-shouldered Dove, Brown Treecreeper, Sulphur-crested Cockatoo and Pale-headed Rosella) and five increased (Peaceful Dove, Pheasant Coucal, Weebill, White-throated Honeyeater and Yellow Oriole). Habitat preference for the species that showed change remained relatively stable between the two survey periods. Some species that were recorded in very low numbers in the original survey and are conside red to be threatened (Brown Treecreeper, Black-faced Woodswallow) remained in very low numbers or decreased in our survey suggesting that there has been no regional recovery of these species. Long-term monitoring can describe important patterns of species change over time, though in the case of large, highly seasonal environments like the tropical savannas, signals of change may manifest over decades rather than annually.

2011 Australian Zoologist volume 35 (3) Knowledge of basic information like taxonomy, distribution and habitat preference for much of Australia’s amphibian and reptile fauna is still increasing. For example, regarding reptiles, Wilson and Swan 2008 state that “more than 20 species have been added to this revised edition, and many maps have been adjusted to accommodate range extensions” in the five years since the first edition (2003). Further descriptions have occurred since then (e.g. Hoskin and Higgie, 2008; Couper et al, 2008).

The domestic cat Felis catus has become a feral predator and conservation threat in many regions of the world. In the northern tropical savannas of Australia, there is limited data on feral cat diet, and there is evidence that some mammal populations in this region are starting to show signs of significant population decline. A total of 169 cat stomach samples were collected from north-eastern Australia from 1996 to 1998. Samples were collected from grassland and woodland habitats in winter and summer periods. A total of 106 unique prey types (grouped into 59 categories), representing 974 items, were recorded from all samples of which 8% were invertebrates, 9% amphibians, 41% reptiles, 20% birds, and 22% mammals. Relative significance of prey items was examined by calculating the Index of Relative Importance. Chi-square comparisons of frequency differences among habitat, season, and sex of cat were also undertaken. The most important prey items were grasshoppers (Orthoptera), centipedes (Chiloptera), dunnarts (Sminthopsis spp.), planigales (Planigale spp.), rabbits, quails (Turnix spp., Coturnix sp.), and geckos (Oedura spp., Gehyra spp.). Amphibians and invertebrates were more frequent in summer (wet season) samples, and mammals were more frequent in winter. Similarly, there were more amphibians in woodland samples and more invertebrates in grasslands. There was high dietary overlap and little difference in the diet of male versus female cats. Increasing cat predation in northern Australia may significantly affect the conservation of key groups already under decline (e.g., mammals) and careful innovative solutions to stem cat predation are needed.

Tropical savannas are an important reservoir of global biodiversity. Australia’s extensive savannas, although still largely intact, are experiencing substantial declines in terrestrial biodiversity due to a variety of interrelated effects of altered fire regimes, grazing and increases in invasive species. These disturbance processes are spatially variable, combine to increase landscape to local-scale landscape heterogeneity, but rarely result in well-defined patch boundaries. We quantified the importance of this heterogeneity for native reptile and small mammal species in a tropical savanna landscape of Queensland, Australia. We used high resolution remote sensing imagery (IKONOS) to map habitat pattern at a 4 m spatial resolution and at variable extents. We found that landscapes dominated by grass or bare ground had low reptile and small mammal diversity, while landscapes with a heterogeneous mix of grass, bare ground and trees had high species diversity and relative abundance of most species. Landscape heterogeneity may increase reptile and small mammal species richness by: (i) increasing the variety and abundance of foraging resources such as seeds and invertebrates; (ii) providing cover from predators and high summer temperatures; and (iii) increasing functional connectivity and dispersal success. The importance of these resources and processes varies among individual species and at different spatial scales, reiterating the need to consider habitat requirements of multiple species in landscape management and conservation planning.

Accurate a priori predictions of the sensitivity of species to vegetation man- agement depend on an understanding of mechanisms underlying species response. To date information on where birds forage in the vegetation strata has been used to predict bird species response to vegetation change caused by livestock grazing. Profiting from this link between vegetation structural diversity and bird diversity, we test whether this variable, bird foraging height, can be used to predict the impact of a different type of habitat alteration; vegetation encroachment. Increases in vegetation density, called 'encroach- ment' or 'thickening', throughout savanna landscapes are considered a serious manage- ment issue for pastoral activities and a potential threat to biodiversity. We developed woody-vegetation-change models to predict the effect of vegetation encroachment on bird species through an understanding of where birds forage in intact vegetation communities. We compare model predictions with bird abundance data collected from 60 field sites representing a single woodland vegetation type, but with a gradient of woody vegetation density caused by clearing, thinning and natural climatic perturbation. Our model suc- cessfully predicted for the majority (80%) of birds considered, whether a species was likely to increase, decrease or remain unaffected by increases in woody vegetation density. We find that the majority of species respond positively to vegetation encroachment. Our approach avoids problems of post hoc data interpretation and tests a specific mechanism underlying bird species response to habitat alteration, bird foraging height. Simple pre- dictive models such as these will assist land managers make informed decisions about management actions and consequences, particularly in cases where decisions need to be made urgently and preclude the collection and analysis of primary ecological data sets.