Suchergebnisse

To assess whether faunal habitat can be enhanced by using artificial refuges, and whether different species preferentially use refuges with differing structural characteristics, we monitored faunal usage of artificially placed log refuges in grazed semi-arid grasslands and woodlands in Terrick Terrick National Park in Victoria. In total, 1131 log refuges were placed at 91 sites across major vegetation types in the reserve. The effect of refuge age was assessed by comparing faunal usage between new refuges and 271 old refuges that had lain in situ for more than 15 years. Refuges were surveyed for fauna monthly between June 2000 and January 2001. Different species preferred refuges with different characteristics. Overall terrestrial fauna, and three native species (Diplodactylus tessellatus, Morethia boulengeri and Suta suta) in particular, were significantly more abundant beneath old refuges, whereas the introduced Mus musculus was significantly more abundant beneath new refuges. Five species (Crinia signifera, Morethia boulengeri, Menetia greyii, Sminthopsis crassicaudata and Suta suta) were significantly more abundant beneath Eucalyptus logs that were large, wide, partially decayed, contained many holes and/or covered many subterranean invertebrate holes. This study demonstrates the effectiveness of installing log refuges in grassy landscapes as a survey method for vertebrate fauna and as a potential habitat-restoration technique to help conserve grassland fauna.

Understanding what factors infl uence species occupancy in human-modifi ed landscapes is a central theme in ecology. We examined scale-dependent habitat relationships and site occupancy in reptiles across three topographically diff erent study areas in south-eastern Australia. We collected presence – absence data on reptiles from 443 sites associated with three longterm biodiversity monitoring programs, on four to seven occasions, between 2001 and 2013. We characterised sites by the following four variable domains: 1) fi eld design, 2) topography, 3) local-scale vegetation attributes and 4) landscapescale vegetation cover. We constructed occupancy models for 14 species and used an information-theoretic approach to compare multiple alternative hypotheses to explain occupancy within and between study areas. We modelled detection probability and used the model with the lowest AIC in subsequent analyses. We then modelled occupancy probability against all subsets of the variable groups (fi eld design, topography, local- and landscape-scale vegetation), as well as a model that held occupancy constant (null model). We found that local-scale vegetation attributes were important for explaining site occupancy in 12/19 possible models, although, in several cases model fi t was improved by the addition of topographic variables or native vegetation cover in the surrounding landscape. Occupancy models for widespread species were broadly congruent across study areas. We demonstrate that topographic variables are important for explaining reptile occupancy in hilly landscapes, and local- and landscape-scale variables are important for explaining reptile occupancy in fl at or gently undulating landscapes. Management actions that improve habitat complexity at a site-level, and encompass entire topographic gradients, will have greater benefi t to woodland reptiles than simply increasing vegetation cover in the surrounding landscape. ; This study was funded by the Australian Government's Caring for our Country scheme, the Murray Local Land Services and the Australian Research Council.

Native vegetation placed under an agri-environment scheme (AES) is purported to support greater biodiversity than vegetation managed for intensive livestock grazing, and conservation reserves are purported to support greater biodiversity than land sharing under AES. These predictions underpin financial incentive delivery programs that enable landholders to adopt environmentally friendly agricultural practices. To evaluate these predictions, we established a biodiversity monitoring program in endangered temperate eucalypt woodland communities in southern Australia. We compared vegetation variables and vertebrate species richness and abundance among sites under different land management between 2010 and 2014. Our sites included: (1) woodland remnants on private property recently placed under an AES land management agreement (land sharing), (2) woodland remnants in State conservation reserves as reference areas (land sparing), and (3) woodland remnants used for intensive livestock production as controls. We used hierarchical generalized linear models to examine patterns of biodiversity among management classes and over time. We found conservation reserves were structurally more complex and floristically richer compared to production sites, and AES supported greater cover of native perennial grass. Reptile and amphibian species richness and abundance, and total bird species richness did not differ significantly among management classes, although AES and reference sites supported more birds of conservation concern. Arboreal marsupials were significantly more species rich in conservation reserves than AES. Temporal patterns in vertebrate species richness were related to post-drought climatic conditions. Our findings suggest that strategies involving land sharing under AES are as effective as land sparing (e.g. conservation reserves) for bird conservation, but alternative strategies may be required to enhance habitat for less mobile species such as frogs and reptiles, or species dependant on old growth vegetation such as arboreal marsupials. ; This study was funded by the North East and Goulburn Broken Catchment Management Authorities, the Australian Research Council and the Australian Government's Caring for our Country initiative.

Context
Artificial refuges (cover boards) are a popular method to survey and monitor herpetofauna worldwide. However, one limitation of using artificial refuges in terrestrial environments is the low detection rates of arboreal species. Furthermore, destructive search techniques can damage critical microhabitat such as exfoliating rock or flaking bark of mature trees.

Aim
We tested a non-destructive, passive method of sampling arboreal reptiles in fragmented agricultural landscapes in south-eastern Australia.

Methods
We installed 84 artificial bark refuges consisting of strips of non-toxic, closed-cell foam attached to eucalypt trees in 13 patches of remnant vegetation. We used Bayesian statistics to compare differences in detection rates among artificial bark refuges, terrestrial artificial refuges and active searches of natural habitat over a 4-year period.

Key results
Active searches combined with terrestrial artificial refuges detected the highest number of reptile species, including several cryptic fossorial species. Artificial bark refuges detected, on average, 132 times more individuals of the arboreal southern marbled gecko, Christinus marmoratus, than did terrestrial refuges. Gecko abundance patterns were related to tree characteristics such as tree size, bark thickness and stand basal area, as well as survey year.

Conclusions
Traditional survey methods such as terrestrial cover boards, in combination with active searches of natural habitat, may significantly underestimate counts for arboreal gecko species.

Implications
Artificial bark refuges provide a cost-effective, non-destructive and durable method for surveying and monitoring arboreal reptiles in woodland environments over short to medium time frames. Foil-backed, closed-cell foam has broad application for use in spatial capture–recapture studies and long-term monitoring of arboreal reptiles. This method also may be effective for procuring records of threatened arboreal geckos or as a solution for providing temporary habitat in ecological restoration projects.

Context
In many parts of the world, artificial refuges (ARs) are increasingly used to survey different kinds of herpetofauna. Despite gaining popularity, the merit of using ARs compared with standardised active searches remains poorly known, as does their application in regions that support species exhibiting varied life-form strategies.

Aims
We examined the effectiveness of using two survey methods, active searches and ARs (corrugated steel, roof tiles and three different timber refuges), to detect herpetofauna in a range of eucalypt-woodland communities in south-eastern Australia.

Methods
We collected count data over a 12-year period from three independent long-term biodiversity monitoring programs in southern New South Wales. We used generalised linear models to compare detection probabilities among survey methods (active searches versus ARs) and among ARs, for each study area.

Key results
In all study areas, active searches detected the highest mean species richness per site. However, both methods provided complimentary species, thereby maximising species inventory at a regional scale. Species more likely to be detected in active searches included diurnally active, terrestrial and arboreal heliotherms, whereas species detected more frequently using ARs included nocturnal thigmotherms.

Conclusions
A combination of active searches and AR types is required to provide regional-scale representative reptile assemblages, although more than five consecutive surveys may be needed before species accumulation curves reach plateaux. In future studies, we recommend using stacks of corrugated steel to detect heliothermic Scincidae and arboreal Gekkonidae, roof tiles to detect thigmothermic Pygopodidae and railway sleepers to detect cryptozoic Elapidae and tunnel-dwelling Gekkonidae.

Implications
Using a combination of ARs and active searches will increase the chance of detecting both common and cryptic species and deploying corrugated steel provides a cost-effective method for surveying reptiles in long-term studies.

Context Freshwater ecosystems rank among the most threatened environments on Earth. Monitoring aquatic and semi-aquatic species is vital to informing conservation of freshwater ecosystems. However, many semi-aquatic mammals can be difficult to detect with conventional survey methods. Aims We aimed to identify the most effective survey method for detecting an Australian semi-aquatic mammal, the rakali (Hydromys chrysogaster). Methods We compared rakali detection rates among camera-trapping, live-trapping and visual surveys, and tested the influence of camera angle, trap proximity to water and time of survey, across the Yanco Creek system in southern New South Wales. Key results Nocturnal spotlight surveys were the most effective method for detecting rakali, with most observations occurring while individuals were foraging or swimming in the water. Camera traps facing a floating platform and cage traps mounted on floating platforms performed better than those deployed on land. Downward-facing camera traps detected rakali three times more often than did forward-facing cameras. Trapping rakali was unreliable, with the species detected at fewer than half of the sites where presence was confirmed via visual observation and camera traps. For species absence to be determined with 95% confidence, 2–4 weeks of nightly trapping is required, compared with six nights of visual surveys or 12 nights for a platform-facing camera. Morning visual surveys were largely ineffective because of predominantly nocturnal rakali activity and difficulty in detecting signs in creek environments. Conclusions The likelihood of detecting rakali can be maximised through the use of nightly spotlighting and deployment of baited camera traps focussed on platforms or natural resting areas within a water body. Implications Understanding the effectiveness of each method is essential for developing species-appropriate protocols for population monitoring. Our findings present suitable options to be further explored among the 100-plus small (<1 kg) semi-aquatic mammals worldwide that share similar behaviours and characteristics to the rakali, many of which are threatened or data deficient.

A large-scale biodiversity monitoring program examining the response of herpetofauna to the Australian Government's Environmental Stewardship Program is taking place in south-eastern Australia within the critically endangered Box Gum Grassy Woodland veget

A large-scale biodiversity monitoring program examining the response of herpetofauna to the Australian Government's Environmental Stewardship Program is taking place in south-eastern Australia within the critically endangered Box Gum Grassy Woodland veget

A large-scale biodiversity monitoring program examining the response of herpetofauna to the Australian Government's Environmental Stewardship Program is taking place in south-eastern Australia within the critically endangered Box Gum Grassy Woodland vegetation community. Field surveys involve counting reptiles in areas under Environmental Stewardship management. These "Stewardship" areas have been matched with areas managed for primary production (domestic livestock grazing). We list reptiles recorded during surveys conducted between 2010 and 2012. We recorded sixty-nine species from ten families. The list will be useful for workers interested in the zoogeographical distribution of reptiles and amphibians in fragmented agricultural woodland ecosystems.

Aim: After environmental disasters, species with large population losses may need urgent protection to prevent extinction and support recovery. Following the 2019-2020 Australian megafires, we estimated population losses and recovery in fire-affected fauna, to inform conservation status assessments and management. Location: Temperate and subtropical Australia. Time period 2019-2030 and beyond. Major taxa: Australian terrestrial and freshwater vertebrates; one invertebrate group. Methods: From > 1,050 fire-affected taxa, we selected 173 whose distributions substantially overlapped the fire extent. We estimated the proportion of each taxon's distribution affected by fires, using fire severity and aquatic impact mapping, and new distribution mapping. Using expert elicitation informed by evidence of responses to previous wildfires, we estimated local population responses to fires of varying severity. We combined the spatial and elicitation data to estimate overall population loss and recovery trajectories, and thus indicate potential eligibility for listing as threatened, or uplisting, under Australian legislation. Results: We estimate that the 2019-2020 Australian megafires caused, or contributed to, population declines that make 70-82 taxa eligible for listing as threatened; and another 21-27 taxa eligible for uplisting. If so-listed, this represents a 22-26% increase in Australian statutory lists of threatened terrestrial and freshwater vertebrates and spiny crayfish, and uplisting for 8-10% of threatened taxa. Such changes would cause an abrupt worsening of underlying trajectories in vertebrates, as measured by Red List Indices. We predict that 54-88% of 173 assessed taxa will not recover to pre-fire population size within 10 years/three generations. Main conclusions We suggest the 2019-2020 Australian megafires have worsened the conservation prospects for many species. Of the 91 taxa recommended for listing/uplisting consideration, 84 are now under formal review through national processes. Improving ...