DOI: 10.3897/natureconservation.61.174618

Authors: Panagiotis I. Karanasios, Dirk S. Schmeller, Yu-Pin Lin

Abstract: Ecological connectivity is crucial for amphibian conservation amid habitat fragmentation from human development. This study assessed stream network connectivity for two stream-breeding amphibians, Rana sauteri and Odorrana swinhoana, across an entire river catchment using the MaxEnt modeling framework. Multiscale stream order predictors represented stream network spatial structure across terrestrial habitats, while citizen-science occurrence and roadkill data serve as proxies for distribution and movement, enabling model construction and cross-validation without direct movement data. Most models performed significantly better than random expectations (p < 0.05–0.001), with high predictive power (AUC = 0.79–0.93; CBI = 0.74–0.97). Tree cover dominated predictor importance (41–70%), while stream order contributed substantially (17–23%) and showed strong predictive power, underscoring the importance of stream networks. R. sauteri responded at broader spatial scales across both occurrence and roadkill models (stream order 50–750 m; tree cover 150–2000 m), whereas O. swinhoana responded at intermediate scales (150–500 m; 250–1500 m), reflecting differences in habitat preferences and breeding behavior. In cross-dataset validation, occurrence models effectively predicted roadkill distributions (AUC = 0.88–0.92), while roadkill models transferred less successfully (AUC = 0.68–0.81), confirming their complementary ecological signals. These results demonstrate that stream order effectively captures the spatial hierarchy of amphibian connectivity across an entire catchment. Our framework enables connectivity analysis in data-limited contexts. The approach can be incorporated into Environmental Impact Assessments to support environmental planning and design by identifying scales of connectivity influence, altitudinal ranges, and topographic features such as valley-bottom zones where habitat suitability and roadkill risk overlap. Ultimately, this approach promotes stream network connectivity that sustains the movement and persistence of multiple taxa, contributing to biodiversity conservation and sustainable development.

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DOI: 10.3897/natureconservation.47.81795

Authors: Sara Santos, Clara Grilo, Fraser Shilling, Manisha Bhardwaj, Cristian Remus Papp

Abstract:

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DOI: 10.3897/natureconservation.31.26263

Authors: Julia J. Back, Andrew J. Hoskins, Roger Kirkwood, John P.Y. Arnould

Abstract: In Australia, a multi-million-dollar industry is based on viewing the Australian fur seal (Arctocephalus pusillus doriferus), predominantly through boat visits to breeding colonies. Regulation of boat approaches varies by site and no systematic investigations have been performed to inform management guidelines. To investigate possible effects of disturbance, experimental boat approaches were made to a colony at Kanowna Island in northern Bass Strait and seal responses were monitored using instantaneous scan sampling. Colony attendance (individuals remaining ashore) was found to be influenced by approach distance and time of day, but was not affected by environmental variables or season, whereas onshore resting behavior was influenced by approach distance, time of day, ambient temperature and wind direction. Onshore resting behavior decreased following experimental boat approaches to 75 m, but changes in abundance of individuals ashore were not observed at this distance. In contrast, approaches to 25 m elicited a strong response, with a steep decline in the number of individuals ashore. This response was strongest when approaches occurred in the morning, with a decline of approximately 47% of individuals, compared to a decline of 21% during afternoon approaches. With regard to onshore resting behavior, afternoon approaches to 75 m led to minimal response. The remaining three combinations of approach distance and time of day had a similar pattern of reductions in the proportion of individuals engaging in onshore resting behavior. The strongest response was again seen during approaches to 25 m conducted in the morning. These behavior changes suggest that unrestricted boat-based ecotourism at Australian fur seal colonies has the potential to increase energy expenditure and reduce the number of seals ashore. Increasing minimum approach distances to ≥75 m and/or restricting visits to afternoons may minimize these impacts at Kanowna Island during the post-molt and non-breeding seasons. As several studies have demonstrated considerable intra-species variation in seal responses to boat approaches, research at other colonies is needed before these findings can be generalized to the remainder of the Australian fur seal population.

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DOI: 10.3897/natureconservation.27.27243

Authors: Denis A. Saunders, Nicole E. White, Rick Dawson, Peter R. M. Mawson

Abstract: The ecology and behaviour of the endangered Carnaby’s Cockatoo Calyptorhynchus latirostris have been studied in detail at Coomallo Creek in the northern wheatbelt of Western Australia from 1969 until the present. Results of research on this breeding population conducted on individually marked birds from 1970 to 1990 were compared with results from analyses of DNA taken from nestlings in the study area from 2003, 2005, and each year from 2009 to 2013. Analyses of DNA confirmed earlier findings about the stability of adult breeding pairs, and that females used the same breeding hollow they used previously, provided the hollow was not occupied when they returned to breed. When moving to another hollow, they chose a hollow in the same vicinity of the previous hollow. Analyses in 22 cases where DNA was obtained from both nestlings of a breeding attempt revealed that in six (27.3%) cases, the second egg was fertilised by a male not paired with the female. These extra-pair copulations were not suspected during the earlier study based on observations of individually marked birds.

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DOI: 10.3897/natureconservation.18.12235

Authors: Shaun W. Molloy, Robert A. Davis, Judy A. Dunlop, Eddie J.B. van Etten

Abstract: The management of populations of threatened species requires the capacity to identify areas of high habitat value. We developed a high resolution species distribution model (SDM) for the endangered Pilbara northern quoll Dasyurus hallucatus, population using MaxEnt software and a combined suite of bioclimatic and landscape variables. Once common throughout much of northern Australia, this marsupial carnivore has recently declined throughout much of its former range and is listed as endangered by the IUCN. Other than the potential threats presented by climate change, and the invasive cane toad Rhinella marina (which has not yet arrived in the Pilbara). The Pilbara population is also impacted by introduced predators, pastoral and mining activities. To account for sample bias resulting from targeted surveys unevenly spread through the region, a pseudo-absence bias layer was developed from presence records of other critical weight-range non-volant mammals. The resulting model was then tested using the biomod2 package which produces ensemble models from individual models created with different algorithms. This ensemble model supported the distribution determined by the bias compensated MaxEnt model with a covariance of of 86% between models with both models largely identifying the same areas as high priority habitat. The primary product of this exercise is a high resolution SDM which corroborates and elaborates on our understanding of the ecology and habitat preferences of the Pilbara Northern Quoll population thereby improving our capacity to manage this population in the face of future threats.

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DOI: 10.3897/natureconservation.12.4863

Authors: Denis Saunders, Rick Dawson, Nick Nicholls

Abstract: It is important to know the age of nestling birds for many ecological and behavioural studies. Various methods have been developed for individual species; most are based on measurements of growth in wings, tarsi or heads/bills, or observations of changes in size, plumage and behaviour over time. However, techniques for aging nestlings have not been established for most avian species. This paper sets out two methods to age nestling Carnaby’s cockatoo, Calyptorhynchus latirostris, an endangered species endemic to southwestern Australia. One method is based on the physical changes in size and plumage during the 10 to 11 weeks of the nestling period, and the other on the relationship between the length of the nestling’s folded left wing and its age developed from data obtained from nestlings of known age. The estimated age of nestlings may be used to extrapolate egg-laying, hatching and fledging dates by taking the 29 days of incubation and the 76 days of the nestling period into account. The method of estimating nestling age based on length of folded left wing provides a more accurate estimate of nestling age than observations of changes in nestling size and plumage. However in situations where it is not possible to handle nestlings, the observation method should provide a reasonable basis for calculating the commencement and end of the breeding season, the length of egg-laying and nestling periods; important population parameters specified for monitoring under the species’ recovery plan.

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DOI: 10.3897/natureconservation.11.4385

Authors: Kaori Yokochi, Roberta Bencini

Abstract: Rope bridges are being increasingly installed worldwide to mitigate the negative impacts of roads on arboreal animals. However, monitoring of these structures is still limited and an assessment of factors influencing the crossing behaviours is lacking. We monitored the use of a rope bridge near Busselton, Western Australia by the endangered western ringtail possums (Pseudocheirus occidentalis) in order to identify the patterns of use and factors influencing the crossings. We installed motion sensor cameras and microchip readers on the bridge to record the crossings made by individual animals, and analysed these crossing data using generalised linear models that included factors such as days since the installation of the bridge, breeding season, wind speed, minimum temperature and moonlight. Possums started investigating the bridge even before the installation was completed, and the first complete crossing was recorded only 36 days after the installation, which is remarkably sooner than arboreal species studied in other parts of Australia. The possums crossed the bridge increasingly over 270 days of monitoring at a much higher rate than we expected (8.87 ± 0.59 complete crossings per night). Possums crossed the bridge less on windy nights and warm nights probably due to the risk of being blown away and heat stress on warmer days. Crossings also decreased slightly on brighter nights probably due to the higher risk of predation. Breeding season did not influence the crossings. Pseudocheirus occidentalis habituated to the bridge very quickly, and our results demonstrate that rope bridges have a potential as an effective mitigation measure against the negative impacts of roads on this species. More studies and longer monitoring, as well as investigating whether crossing results in the restoration of gene flow are then needed in order to further assess the true conservation value of these crossing structures.

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DOI: 10.3897/natureconservation.11.4434

Authors: Peter G. Spooner

Abstract: Roads corridors are a conspicuous part of most landscapes, which are gaining greater recognition for their role in nature conservation. However roads cause wildlife mortality, alter water and nutrient flows, change local microclimatic conditions, act as vectors for weeds and pest animals, and have other far-reaching effects. Not surprisingly, there is much attention from both road and conservation managers to lessen these impacts, with an emphasis on developing solutions to mitigate the barrier effects of major roads to wildlife movements. However in many anthropogenic landscapes, road corridors can also provide key habitat and connectivity for local biodiversity. In particular, where traffic volumes are low, minor roads often provide critical habitat and refuge for many native species. Knowledge of the ecology and biodiversity conservation values of minor rural road verges has been underpinned by studies in various contexts, such as sunken roads, field margins and hedgerow networks in Europe, to stock routes in Spain and Australia. Despite their different histories and management constructs, important commonalties have been highlighted in terms of their biodiversity values, and the factors which influence these values. As such, minor rural road networks can be vital in providing connected, functioning ecosystems within rural landscapes. The importance of vegetated minor rural road networks will only become more pressing with future climate change. In Australia, road management authorities are tasked with the dual roles of maintaining road transport needs (i.e. priorities for road maintenance and safety concerns), whilst maintaining the environmental values of roads. This paper reviews the biodiversity values of minor rural roads, discusses the challenges and constraints in managing these values, and describes the case of identifying historic roads as an example of enhancing conservation management of these important habitats in rural landscapes.

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DOI: 10.3897/natureconservation.11.5458

Authors: Andreas Seiler, Jan-Olof Helldin

Abstract: no abstract provided for this editorial

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DOI: 10.3897/natureconservation.10.8739

Authors: James A. Fitzsimons

Abstract: Despite the recognised importance of private land for biodiversity conservation, there has been little research into systems of private protected areas at a country-wide level. Here I look at definitions, legislation, ownership, management approaches and effectiveness, distribution and incentives provided to private protected areas in Australia. The term ‘private protected areas’, although increasingly used, still suffers from a lack of a clear and concise definition in Australia. Australian states and territories have legislation enabling the application of conservation covenants over private land; covenants being the primary mechanism to secure conservation intent on the title of the land in perpetuity. If considering all ‘in perpetuity’ conservation covenants under a dedicated program to be private protected areas and land owned by non-government organisations and managed for the purpose of biodiversity conservation, there were approximately 5,000 terrestrial properties that could be considered private protected areas in Australia covering 8,913,000 ha as at September 2013. This comprises almost 4,900 conservation covenants covering over 4,450,000 ha and approximately 140 properties owned by private land trusts covering approximately 4,594,120 ha. Most conservation covenanting programs now seek to complement the comprehensiveness, adequacy and representativeness of the public reserve system, either stating so explicitly or by aiming to protect the highest priority ecosystems on private land. There are a range of incentives offered for private land conservation and requirements of owners of private protected areas to report on their activities vary in Australia. However, there are a number of key policy challenges that need to be addressed if private protected areas are to achieve their full potential in Australia, including managing broad-scale ecosystem processes, protection and tenure reform, improved financial incentives, and access to emerging ecosystem service markets.

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DOI: 10.3897/natureconservation.9.8385

Authors: Denis Saunders, Rick Dawson, Alison Doley, John Lauri, Anna Le Souef, Peter Mawson, Kristin Warren, Nicole White

Abstract: Nature conservation and agricultural production may be considered as conflicting objectives, but for a wheat and sheep property in Western Australia they have been pivotal management objectives for the last 48 years. Koobabbie, a 7,173 ha property, has retained 41.5% of the original native vegetation, and is a designated Important Bird Area by BirdLife Australia, while still being an economically profitable agricultural enterprise. Since 1987 the owners of Koobabbie have kept detailed records of the avifauna of the property, and encouraged staff from government, non-government and academic organisations to conduct research and monitoring of the endangered Carnaby’s Cockatoo Calyptorhynchus latirostris breeding on their property. In addition, they have instituted control programs for two over-abundant cockatoo species which compete with Carnaby’s Cockatoo for nest sites, and for Feral Cats that are predators of nesting female Carnaby’s Cockatoo and their offspring. This paper presents the results of research and monitoring from 2003-2013, during which seven artificial nesting hollows were erected, and former active nest hollows that had become derelict were repaired. By 2008, the number of breeding pairs on the property was at least 27, but two mass deaths of breeding females in 2009 and 2012 reduced the number of breeding pairs by 80%. This study illustrates the importance of monitoring conservation on private property, and raises a number of issues in relation to management of endangered species dependent on large hollow-bearing trees on private property.

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