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Citizen‐science projects focused on ecology and conservation have been growing in popularity in recent years, offering many opportunities for researchers and volunteers alike. Two principal approaches to citizen‐science projects in ecology can be characterized as the data‐first approach and the question‐first approach. Here, we highlight the value of question‐first citizen‐science projects for providing insights into the ecology and management of urban wildlife, using case studies on (1) beneficial insects (pollinators, predators and parasitoids) and (2) possums and gliders in Australian cities and towns. The question‐first approach has many benefits, offering a platform to engage volunteers with the scientific process and the broader context of an ecological or conservation problem, while also connecting them with their local environment. Identifying the questions to be addressed in a citizen‐science project ahead of data collection allows for co‐design and stronger collaboration with volunteers, community groups, local experts, and landscape managers. Question‐first citizen science can also provide valuable ecological data that extend substantially beyond presence‐only records, including presence‐absence data collected via timed surveys and information on animal behavior and interspecific interactions. However, establishing and maintaining question‐first citizen‐science projects can be challenging, requiring the building and maintenance of many relationships and a multidisciplinary approach that goes well beyond the usual activities of an academic researcher. Well‐designed, question‐first citizen science has the capacity to achieve both scientific rigor and meaningful engagement with volunteer participants. [ABSTRACT FROM AUTHOR]

Abstract Cities tend to be built in areas of high biodiversity, and the accelerating pace of urbanization threatens the persistence of many species and ecological communities globally. However, urban environments also offer unique prospects for biological conservation, with multiple benefits for humans and other species. We present seven ecological principles to conserve and increase the biodiversity of cities, using metaphors to bridge the gap between the languages of built-environment and conservation professionals. We draw upon John Ruskin's famous essay on the seven lamps of architecture, but more generally on the thinking of built-environment pioneers such as Patrick Geddes (1854–1932) who proposed a synoptic view of the urban environment that included humans and non-humans alike. To explain each principle or 'lamp' of urban biodiversity, we use an understanding from the built-environment disciplines as a base and demonstrate through metaphor that planning for the more-than-human does not require a conceptual leap. We conclude our discussion with ten practical strategies for turning on these lamps in cities. Urban planners, architects, landscape architects, engineers and other built-environmental professionals have a key role to play in a paradigm shift to plan for the more-than-human, because of their direct influence on the evolving urban environment. This essay is intended to increase dialogue between ecologists and members of these professions, and thus increase the biodiversity of cities around the world. Highlights • Cities and towns offer important opportunities for the conservation of biodiversity. • A paradigm shift that integrates biodiversity into the urban fabric is required. • We present seven ecological principles to increase the biodiversity of cities through planning for the more-than-human. [ABSTRACT FROM AUTHOR]

Wildfires are increasing in both frequency and intensity in many ecosystems, with climate change models predicting further escalations in fire-prone environments. Set against this background is the global decline of amphibians, with up to 40% of species facing extinction from multiple additive threats. Despite these disturbing figures, it is currently unclear how increasing fire frequency may impact the long-term persistence of frog populations., Following a severe wildfire in south-eastern Australia in 2009, field surveys indicated healthy tree frog populations. However, the 2009 fire had significant impacts on genetic diversity, including increased levels of inbreeding and declines in effective population size., Using stochastic population modelling under a range of fire-frequency scenarios, we demonstrate that amphibian populations in fire-prone environments may be increasingly vulnerable to extinction, particularly where rates of immigration are low., Synthesis and applications. This study of amphibian population genetics before and after a major wildfire emphasizes the importance of integrating both ecological and genetic data into population models. This will help managers make more appropriate conservation decisions regarding fire management of natural environments, especially those containing threatened populations. Priorities for agencies involved in planning controlled burns should consider carefully the timing of controlled burns, along with maintaining habitat connectivity. [ABSTRACT FROM AUTHOR]

Urbanization changes the physical environment of nonhuman species but also markedly changes their acoustic environment. Urban noise interferes with acoustic communication in a range of animals, including birds, with potentially profound impacts on fitness. However, a mechanistic theory to predict which species of birds will be most affected by urban noise is lacking. We develop a mathematical model to predict the decrease in the active space of avian vocal signals after moving from quiet forest habitats to noisy urban habitats. We find that the magnitude of the decrease is largely a function of signal frequency. However, this relationship is not monotonic. A metaregression of observed increases in the frequency of birdsong in urban noise supports the model's predictions for signals with frequencies between 1.5 and 4 kHz. Using results of the metaregression and the model described above, we show that the expected gain in active space following observed frequency shifts is up to 12% and greatest for birds with signals at the lower end of this frequency range. Our generally applicable model, along with three predictions regarding the behavioral and population-level responses of birds to urban noise, represents an important step toward a theory of acoustic communication in urban habitats. [ABSTRACT FROM AUTHOR]

Abstract: Private property accounts for much of the planet's arable land, and most of this has been cleared for agricultural production. Agricultural areas retain only fragments of their original vegetation and this has been detrimental to many native plant and animal species. Habitat restoration and revegetation may be able to reconnect and enlarge existing remnant areas in agricultural landscapes and, thereby, enhance native plant and animal communities. However, conservation initiatives will be successful only if landowners actively participate in restoration actions. This study used four hundred postal questionnaires to assess the degree to which landowners in two regions of south-eastern Australia adopt restoration activities, their opinions regarding remnant and revegetated land and their management actions in these areas. One hundred and seventy nine completed questionnaires were received. Three quarters of respondents had undertaken restoration on their property or were planning to revegetate in the future. Landcare members were most likely to have previously revegetated and future revegetation intentions were best predicted by previous restoration activities and a primary income source that was off-farm. Landowners were more likely to manage restored and remnant areas if they perceived threats such as weeds, pest animals and fire risk would be detrimental to their property, than to enhance environmental outcomes. These results indicate that landowners are interested in restoring natural areas, but without greater assistance to restore ground layers and manage perceived threats posed by fire and invasive plants and animals, restoration actions will not have their desired biodiversity benefits. [Copyright &y& Elsevier]

Highlights: [•] Beetle faunas in agricultural landscapes are a robust subset of the beetle communities that existed prior to land clearing. [•] Habitat restoration may be ineffective without the translocation of specialised beetles and the introduction of ground layers. [•] Beetle species and trophic groups are adapted to agricultural vegetation variables rather than vegetation in remnant areas. [•] Beetle community composition is influenced by environmental variables such as native vegetation structure and soil type. [ABSTRACT FROM AUTHOR]

Recent studies in the Northern Hemisphere have shown that songbirds living in noisy urban environments sing at higher frequencies than their rural counterparts. However, several aspects of this phenomenon remain poorly understood. These include the geographical scale over which such patterns occur (most studies have compared local populations), and whether they involve phenotypic plasticity or microevolutionary change. We conducted a field study of silvereye (Zosterops lateralis) vocalizations over more than 1 million km² of urban and rural south-eastern Australia, and compared possible effects of urban noise on songs (which are learned) and contact calls (which are innate). Across 14 paired urban and rural populations, silvereyes consistently sang both songs and contact calls at higher frequencies in urban environments. Syllable rate (syllables per second) decreased in urban environments, consistent with the hypothesis that reflective structures degrade song and encourage longer intervals between syllables. This comprehensive study is, to our knowledge, the first to demonstrate varied adaptations of urban bird vocalizations over a vast geographical area, and to provide insight into the mechanism responsible for these changes. [ABSTRACT FROM AUTHOR]

1. Ecologists and conservation biologists consider many issues when designing a field study, such as the expected value of the data, the interests of the study species, the welfare of individual organisms and the cost of the project. These different issues or values often conflict; however, neither animal ethics nor environmental ethics provides practical guidance on how to assess trade-offs between them. 2. We developed a decision framework for considering trade-offs between values in ecological research, drawing on the field of ecological ethics. We used a case study of the population genetics of three frog species, in which a researcher must choose between four methods of sampling DNA from the study animals. We measured species welfare as the reduction in population growth rate following sampling, and assessed individual welfare using two different definitions: (i) the level of suffering experienced by an animal, and (ii) the level of suffering combined with loss of future life. 3. Tipping the tails of tadpoles ranked as the best sampling method for species welfare, while collecting whole tadpoles and buccal swabbing of adult frogs ranked best for the first and second definitions of individual welfare, respectively. Toe clipping of adult frogs ranked as the worst sampling method for species welfare and the first definition of individual welfare, and equal worst for the second definition of individual welfare. 4. When considering species and individual welfare simultaneously, toe clipping was clearly inferior to the other sampling methods, but no single sampling method was clearly superior to the other three. Buccal swabbing, collecting tadpoles and tail tipping were all preferred options, depending on the definition of individual welfare and the level of precision with which we assessed species welfare. 5. Synthesis and applications. The decision framework we present can be used by ecologists to assess ethical and other trade-offs when planning field studies. A formal decision analysis makes transparent how a researcher might negotiate competing ethical, financial and practical objectives. Defining the components of the decision in this way can help avoid errors associated with human judgement and linguistic uncertainty. [ABSTRACT FROM AUTHOR]

Roadside habitats are important for a range of taxa including plants, insects, mammals, and birds, particularly in developed countries in which large expanses of native vegetation have been cleared for agriculture or urban development. Although roadside vegetation may provide suitable habitat for many species, resident animals can be exposed to high levels of traffic noise, visual disturbance from passing vehicles, and the risk of collision with cars and trucks. Traffic noise can reduce the distance over which acoustic signals such as song can be detected, an effect known as acoustic interference or masking. Studies from the northern hemisphere show that the singing behavior of birds changes in the presence of traffic noise. We investigated the impact of traffic noise and traffic volume on two species of birds, the Grey Shrike-thrush (Colluricincla harmonica) and the Grey Fantail (Rhipidura fuliginosa), at 58 roadside sites on the Mornington Peninsula, southeastern Australia. The lower singing Grey Shrike-thrush sang at a higher frequency in the presence of traffic noise, with a predicted increase in dominant frequency of 5.8 Hz/dB of traffic noise, and a total effect size of 209 Hz. In contrast, the higher singing Grey Fantail did not appear to change its song in traffic noise. The probability of detecting each species on a visit to a site declined substantially with increasing traffic noise and traffic volume, with several lines of evidence supporting a larger effect of traffic noise. Traffic noise could hamper detection of song by conspecifics, making it more difficult for birds to establish and maintain territories, attract mates and maintain pair bonds, and possibly leading to reduced breeding success in noisy roadside habitats. Closing key roads during the breeding season is a potential, but untested, management strategy to protect threatened bird species from traffic noise and collision with vehicles at the time of year when they are most vulnerable to their impacts. Other management options include reducing the speed and/or volume of traffic on such roads to an acceptably low level. Ours is the first study to investigate the effect of traffic noise on the singing behavior of birds in the southern hemisphere. [ABSTRACT FROM AUTHOR]

Male frogs call to attract females for mating and to defend territories from rival males. Female frogs of some species prefer lower-pitched calls, which indicate larger, more experienced males. Acoustic interference occurs when background noise reduces the active distance or the distance over which an acoustic signal can be detected. Birds are known to call at a higher pitch or frequency in urban noise, decreasing acoustic interference from low-frequency noise. Using Bayesian linear regression, we investigated the effect of traffic noise on the pitch of advertisement calls in two species of frogs, the southern brown tree frog (Litoria ewingii) and the common eastern froglet (Crinia signifera). We found evidence that L. ewingii calls at a higher pitch in traffic noise, with an average increase in dominant frequency of 4.1 Hz/dB of traffic noise, and a total effect size of 123 Hz. This frequency shift is smaller than that observed in birds, but is still large enough to be detected by conspecific frogs and confer a significant benefit to the caller. Mathematical modelling predicted a 24% increase in the active distance of a L. ewingii call in traffic noise with a frequency shift of this size. Crinia signifera may also call at a higher pitch in traffic noise, but more data are required to be confident of this effect. Because frog calls are innate rather than learned, the frequency shift demonstrated by L. ewingii may represent an evolutionary adaptation to noisy conditions. The phenomenon of frogs calling at a higher pitch in traffic noise could therefore constitute an intriguing trade-off between audibility and attractiveness to potential mates. [ABSTRACT FROM AUTHOR]

Marking animals so that they are uniquely identifiable provides information that may assist conservation efforts. Nevertheless, some methods used to mark animals can be harmful. We used mathematical methods to assess the trade-off between the impact of marking threatened species and the value of the information gained. We considered the case where 2 management strategies, each aiming to improve a species' survival rate, are implemented in an experimental phase. The results of the experiment were applied in a postexperimental management phase. We expressed the expected number of survivors in both phases mathematically, accounting for any mortality caused by the experiment, and determined the proportion of animals to mark to maximize this number. The optimal number of animals to mark increased with the number of individuals available for the experiment and with the number of individuals to be managed in the future. The optimal solution was to mark only 25% of the animals when there were 1000 individuals available for the experiment, the results were used to manage 2000 individuals, and marking caused mortality of 1%. Fewer animals were marked when there were fewer animals in either phase or when marking caused higher mortality. In the case of the Helmeted Honeyeater (Lichenostomus melanops cassidix), the optimal proportion to mark was <1 if the mortality rate was >0.15%–1%, with the threshold depending on the number of animals in the experimental and postexperimental phases. The trade-off between gaining more information about a species and possibly harming individuals of that species by marking them is difficult to assess subjectively. We show how to determine objectively the optimal proportion of animals to mark to enhance the management of threatened species. [ABSTRACT FROM AUTHOR]

Abstract: Urban climates are known to differ from those of the surrounding rural areas, as human activities in cities lead to changes in temperature, humidity and wind regimes. These changes can in turn affect the geographic distribution of species, the behaviour of animals and the phenology of plants. The grey-headed flying-fox (Pteropus poliocephalus) is a large, nomadic bat from eastern Australia that roosts in large colonies known as camps. Historically a warm temperate to tropical species, P. poliocephalus recently established a year-round camp in the Royal Botanic Gardens Melbourne. Using a bioclimatic analysis, we demonstrated that on the basis of long-term data, Melbourne does not fall within the climatic range of other P. poliocephalus camp sites in Australia. Melbourne is drier than other summer camps, and cooler and drier than other winter camps. The city also receives less radiation, in winter and annually, than the other summer and winter camps of P. poliocephalus. However, we found that temperatures in central Melbourne have been increasing since the 1950s, leading to warmer conditions and a reduction in the number of frosts. In addition, artificial watering of parks and gardens in the city may contribute the equivalent of 590mm (95% CI: 450–720mm) of extra rainfall per year. It appears that human activities have increased temperatures and effective precipitation in central Melbourne, creating a more suitable climate for camps of the grey-headed flying-fox. As demonstrated by this example, anthropogenic climate change is likely to complicate further the task of conserving biological diversity in urban environments. [Copyright &y& Elsevier]

1. Toe clipping is commonly used in population ecology to identify individual amphibians, particularly frogs and toads. Toe clipping may influence the return rate of the marked animals, although results of previous studies have appeared to be contradictory. 2. We re-analysed available data using Bayesian statistics to examine how the return rate of frogs may change with the number of toes removed. 3. Our re-analysis indicated that toe clipping reduces the return rate by 4–11% for each toe removed after the first, assuming the effect is the same for all toes. 4. A second analysis allowed the effect of removing each toe to change linearly with the number removed. This indicated that when one toe had already been removed, the return rate was reduced by 3·5% (95% credibility interval of 0–7%) upon removal of a second. The reduction in return rate on removal of an additional toe was 30% (95% credibility interval of 20–39%) when seven toes had already been removed. 5. When considering the cumulative effect of toe clipping, the return rate of frogs with two toes removed was estimated to be 96% of those with one toe removed. This ratio decreased to 28% for frogs with eight toes removed. 6. Synthesis and applications. We found that the effect of toe clipping on the return rate of amphibians increases with the number of toes removed. Because this effect is reasonably consistent among studies, the estimated impact should be recognized in future work that uses toe clipping to estimate population sizes and survival rates. In addition, our study has important implications for the ethical treatment of animals, the continued use of toe clipping to mark species of conservation concern, and the removal of multiple toes from an individual frog or toad. Journal of Applied Ecology (2004) 41, 780 –786 [ABSTRACT FROM AUTHOR]

The habitat hectares approach is an explicit, quantitative method for assessing the quality of vegetation by adding scores that are assigned to 10 habitat attributes. We believe it will be more repeatable and transparent than other methods that rely on subjective judgement. However, we have four principal criticisms of the method as it is currently proposed: (i) measurement of some of the attributes may be subject to considerable error that varies among assessors; (ii) the comparison of each measure with a single benchmark does not accommodate appropriate disturbance regimes; (iii) the proposed combination of attributes leads to some apparent internal inconsistencies; and (iv) it is not clear how the method will actually be used in practice. We suggest modifications to address these concerns and improve the proposed method. Finally, we make additional suggestions about the method's potential application, including: separate reporting of the extent and quality of different vegetation types to avoid the inappropriate combination of measures of area and quality; valuing appropriate disturbance regimes in natural areas; and considering very carefully the application of compensation or mitigation measures. [ABSTRACT FROM AUTHOR]

Loss and fragmentation of habitat resulting from the clearing of forests for agriculture and urban development threaten the persistence of thousands of species worldwide. The clearing of native forest to plant a monoculture of exotic trees may also reduce and fragment the habitat available for indigenous plants and animals. Metacommunity theory suggests that the species richness of a community in a patch of habitat will increase with patch size but decrease with patch isolation. We investigated whether replacement of native Eucalyptus forest with a plantation of Pinus radiata has reduced and fragmented habitat for frogs, leading to a lower species richness of frog communities in the pine plantation and in small and/or isolated remnant patches of native forest. We surveyed frogs at 60 sites at streams and wetlands in the pine plantation, remnant patches of native forest surrounded by pines, and adjacent areas of contiguous native forest near Tumut in New South Wales, Australia. Only two of eight species of frogs were recorded in the pine plantation, and regression modelling indicated that streams and wetlands in the pines supported fewer frog species than those in remnant patches or the intact native forest. In addition, species richness tended to be higher at wide, shallow swamps and marshes near the headwaters of streams, with herbs, grasses, shrubs, reeds, sedges and rushes in the emergent and fringing vegetation. There was little evidence to suggest that larger eucalypt remnants supported more species of frogs, or that remnants isolated by greater expanses of pines supported fewer species, but we had low power to detect these effects with our data set. Our results support the preservation of all remnants of native forest along drainage lines and around swamps, soaks and bogs, regardless of size. Where new pine plantations are established, for example, on cleared agricultural land, care should be taken to maintain the structural and vegetative characteristics of water bodies to ensure that they continue to provide suitable breeding habitat for frogs. [Copyright &y& Elsevier]

Many animals use acoustic signals as a means of intra- and inter-specific communication. For example, male anuran amphibians produce advertisement calls to attract females for breeding, and as a territorial signal. The production of acoustic signals can be energetically costly, and the distance over which a signal is effective depends on a range of variables including the location of the caller and receiver, ambient conditions and the habitat through which the sound travels. This paper presents a spatially explicit model of the propagation of an anuran advertisement call across a landscape, using the example of the northern spring peeper Pseudacris crucifer crucifer. The model is used to investigate (a) the effect of habitat, caller position and chorus noise on the effective distance of a call with a frequency of approximately 3 kHz; and (b) the energetics and efficiency of calling at different intensities and from different locations in the landscape. Calling next to still water or from an elevated perch increases, while calling in a chorus decreases, the distance over which a female can distinguish an individual male''s call. For a given call intensity and calling rate, a male spring peeper will get the greatest “bang for its energetic buck” if it calls next to still water in the absence of chorus noise. However, when a chorus of spring peepers is gathered at a pond, calling from an elevated position away from the pond (and the chorus noise) will maximise the effective distance of an individual call, although this may entail other costs. The model presented here is the first realistic, interactive mathematical model of the propagation of animal sounds across a landscape, and uses a gis interface to display the effect of habitat and caller position on animal communication. It has applications for both research and teaching, and a copy can be obtained free of charge by contacting the author. [Copyright &y& Elsevier]

Toe clipping is a common method of marking anurans for population studies. We re-analysed data from four published studies investigating the relationship between return rate and number of toes clipped for three anuran species: Bufo fowleri, Crinia signifera and Hyla labialis. Although these studies claimed contradictory results, a re-analysis of the data with proper attention to statistical power demonstrated a statistically significant decline of 6-18% in the probability of return for each toe removed after the first, in three of the four studies examined. The probability that the fourth study would detect a statistically significant effect of toe clipping was low unless the size of the effect was overwhelming. These results provide consistent evidence that toe clipping decreases the return rate of marked anurans, and demonstrates the importance of considering statistical power during data analysis. Use of toe clipping for mark-recapture studies may produce estimates of population parameters that are biased by the same magnitude as the return rates, unless researchers control for the effect of this marking method. [ABSTRACT FROM AUTHOR]

ABSTRACT: Many wetlands harbour highly diverse biological communities and provide extensive ecosystem services; however, these important ecological features are being altered, degraded and destroyed around the world. Despite a wealth of research on how animals respond to anthropogenic changes to natural wetlands and how they use created wetlands, we lack a broad synthesis of these data. While some altered wetlands may provide vital habitat, others could pose a considerable risk to wildlife. This risk will be heightened if such wetlands are ecological traps – preferred habitats that confer lower fitness than another available habitat. Wetlands functioning as ecological traps could decrease both local and regional population persistence, and ultimately lead to extinctions. Most studies have examined how animals respond to changes in environmental conditions by measuring responses at the community and population levels, but studying ecological traps requires information on fitness and habitat preferences. Our current lack of knowledge of individual‐level responses may therefore limit our capacity to manage wetland ecosystems effectively since ecological traps require different management practices to mitigate potential consequences. We conducted a global meta‐analysis to characterise how animals respond to four key drivers of wetland alteration: agriculture, mining, restoration and urbanisation. Our overarching goal was to evaluate the ecological impacts of human alterations to wetland ecosystems, as well as identify current knowledge gaps that limit both the current understanding of these responses and effective wetland management. We extracted 1799 taxon‐specific response ratios from 271 studies across 29 countries. Community‐ (e.g. richness) and population‐level (e.g. density) measures within altered wetlands were largely comparable to those within reference wetlands. By contrast, individual fitness measures (e.g. survival) were often lower, highlighting the potential limitations of using only community‐ and population‐level measures to assess habitat quality. Only four studies provided habitat‐preference data, preventing investigation of the potential for altered wetlands to function as ecological traps. This is concerning because attempts to identify ecological traps may detect previously unidentified conservation risks. Although there was considerable variability amongst taxa, amphibians were typically the most sensitive taxon, and thus, may be a valuable bio‐indicator of wetland quality. Despite suffering reduced survival and reproduction, measures such as time to and mass at metamorphosis were similar between altered and reference wetlands, suggesting that quantifying metamorphosis‐related measures in isolation may not provide accurate information on habitat quality. Our review provides the most detailed evaluation to date of the ecological impacts of human alterations to wetland ecosystems. We emphasise that the role of wetlands in human‐altered ecosystems can be complex, as they may represent important habitat but also pose potential risks to animals. Reduced availability of natural wetlands is increasing the importance of altered wetlands for aquatic animals. Consequently, we need to define what represents habitat quality from the perspective of animals, and gain a greater understanding of the underlying mechanisms of habitat selection and how these factors could be manipulated. Furthermore, strategies to enhance the quality of these wetlands should be implemented to maximise their conservation potential. [ABSTRACT FROM AUTHOR]

Urbanization affects streams by modifying hydrology, increasing pollution and disrupting in-stream and riparian conditions, leading to negative responses by biotic communities. Given the global trend of increasing urbanization, improved understanding of its direct and indirect effects at multiple scales is needed to assist management. The theory of stream ecology suggests that the riverscape and the surrounding landscape are inextricably linked, and watershed-scale processes will also affect in-stream conditions and communities. This is particularly true for species with semi-aquatic life cycles, such as amphibians, which transfer energy between streams and surrounding terrestrial areas. We related measures of urbanization at different scales to frog communities in streams along an urbanization gradient in Melbourne, Australia. We used boosted regression trees to determine the importance of predictors and the shape of species responses. We then used structural equation models to investigate possible indirect effects of watershed imperviousness on in-stream parameters. The proportion of riparian vegetation and road density surrounding the site at the reach scale (500-m radius) had positive and negative effects, respectively, on species richness and on the occurrence of the two most common species in the area (Crinia signifera and Limnodynastes dumerilii). Road density and local aquatic vegetation interacted in influencing species richness, suggesting that isolation of a site can prevent colonization, in spite of apparently good local habitat. Attenuated imperviousness at the catchment scale had a negative effect on local aquatic vegetation, indicating possible indirect effects on frog species not revealed by single-level models. Processes at the landscape scale, particularly related to individual ranging distances, can affect frog species directly and indirectly. Catchment imperviousness might not affect adult frogs directly, but by modifying hydrology it can disrupt local vegetation and prove indirectly detrimental. Integrating multiple-scale management actions may help to meet conservation targets for streams in the face of urbanization. [ABSTRACT FROM AUTHOR]

Spatial and temporal partitioning of resources underlies the coexistence of species with similar niches. In communities of frogs and toads, the phenology of advertisement calling provides insights into temporal partitioning of reproductive effort and its implications for community dynamics. This study assessed the phenology of advertisement calling in an anuran community from Melbourne, in southern Australia. We collated data from 1432 surveys of 253 sites and used logistic regression to quantify seasonality in the nightly probability of calling and the influence of meteorological variables on this probability for six species of frogs. We found limited overlap in the predicted seasonal peaks of calling among these species. Those shown to have overlapping calling peaks are unlikely to be in direct competition, due to differences in larval ecology ( Crinia signifera and Litoria ewingii) or differences in calling behavior and acoustics ( Limnodynastes dumerilii and Litoria raniformis). In contrast, closely related and ecologically similar species ( Crinia signfera and Crinia parinsignifera; Litoria ewingii and Litoria verreauxii) appear to have staggered seasonal peaks of calling. In combination with interspecific variation in the meteorological correlates of calling, these results may be indicative of temporal partitioning of reproductive activity to facilitate coexistence, as has been reported for tropical and temperate anurans from other parts of the globe. [ABSTRACT FROM AUTHOR]

Abstract: We investigated habitat variables influencing the species richness and composition of frog assemblages at forest streams in southeast Queensland, Australia, to (i) determine whether these assemblage attributes can be predicted from the nature of the local habitat, and (ii) assess the value of species richness as a measure of the structure of frog assemblages. Stream size (as measured by the annual volume of precipitation in the upstream catchment) was found to be a significant predictor of the species richness of an assemblage, while stream size, understorey floristics in the riparian zone, the presence of palms and elevation were significantly correlated with the composition of assemblages. No relationship was found between broad forest type and the species richness or composition of frog assemblages. Species richness was not an informative description of the composition of frog assemblages, as assemblages with identical species richness had a low average compositional similarity. Results of this study indicate that frogs are responding to local, ground-level stream and vegetation variables, a finding of both ecological interest and practical significance for the conservation management of forest-dwelling frogs. [ABSTRACT FROM AUTHOR]

Many passerines adjust song attributes to avoid potential masking by anthropogenic noise. The costs of masking should be particularly high for vocalizations important for survival (e.g. alarm calls), but few studies have investigated how such calls are affected. We compared urban and rural silvereye, Zosterops lateralis , alarm calls across southeastern Australia, and found that urban calls had lower average, peak and maximum frequencies than rural calls. The average, peak and maximum frequency of alarm calls also decreased linearly with increasing background noise. The direction of this frequency shift runs contrary to expectations and previous findings of higher-pitched avian vocal signals in urban habitats, including higher-pitched song and contact calls in urban silvereyes. However, assuming no change in call amplitude, acoustic modelling indicates that the observed frequency shift would lead to a 20% increase in the predicted active space of alarm calls (i.e. the distance over which the calls can be detected by a conspecific bird) in urban noise, and therefore may be potentially adaptive. Our findings highlight the importance of considering behavioural and ecological contexts in urban acoustic-adaptation studies. [ABSTRACT FROM AUTHOR]

The survey of plant and animal populations is central to undertaking field ecology. However, detection is imperfect, so the absence of a species cannot be determined with certainty. developed to account for imperfect detectability during surveys do not yet account for stochastic variation in detectability over time or space. When each survey entails a fixed cost that is not spent searching (e.g., time required to travel to the site), stochastic detection rates result in a trade-off between the number of surveys and the length of each survey when surveying a single site. We present a model that addresses this trade-off and use it to determine the number of surveys that: 1) maximizes the expected probability of detection over the entire survey period; and 2) is most likely to achieve a minimally-acceptable probability of detection. We illustrate the applicability of our approach using three practical examples (minimum survey effort protocols, number of frog surveys per season, and number of quadrats per site to detect a plant species) and test our model's predictions using data from experimental plant surveys. We find that when maximizing the expected probability of detection, the optimal survey design is most sensitive to the coefficient of variation in the rate of detection and the ratio of the search budget to the travel cost. When maximizing the likelihood of achieving a particular probability of detection, the optimal survey design is most sensitive to the required probability of detection, the expected number of detections if the budget were spent only on searching, and the expected number of detections that are missed due to travel costs. We find that accounting for stochasticity in detection rates is likely to be particularly important for designing surveys when detection rates are low. Our model provides a framework to do this. [ABSTRACT FROM AUTHOR]

Climate change and urbanization are among the most serious threats to amphibians, although little is known about their combined effects. We used a predictive spatial habitat suitability model to explore the potential impacts of climate change and urban development on the spotted marsh frog ( Limnodynastes tasmaniensis) on the urban-fringe of Melbourne, Australia. The CSIRO climate-change predictions for the region indicate likely temperature increases of 3°C, and annual rainfall reductions of around 200 mm by the year 2070. Much of the study area overlaps a region that has been identified as one of the city's growth corridors. We used Bayesian logistic regression modelling to estimate current and future habitat suitability of pond sites in the Merri Creek catchment, exploring a range of best- to worst-case scenarios through the use of hydrological and urbanization models. Our predictions for 2070, even under a moderate climate-change scenario, suggest that the majority of ponds in the study area will be dry throughout much of the year. This has obvious implications for L. tasmaniensis, which is an aquatic breeding species. However, in the short term, urbanization is likely to have a more significant effect on the distribution of L. tasmaniensis in the Merri Creek catchment, particularly if development moves beyond the current urban growth boundary. The combined effects of climate change and urbanization could have a profound impact on the species, potentially causing it to disappear from within the study area. We provide recommendations for including such predictive models in urban planning and restoration activities to prepare for future conservation challenges. [ABSTRACT FROM AUTHOR]

Aim Conservation practitioners use biological surveys to ascertain whether or not a site is occupied by a particular species. Widely used statistical methods estimate the probability that a species will be detected in a survey of an occupied site. However, these estimates of detection probability are alone not sufficient to calculate the probability that a species is present given that it was not detected. The aim of this paper is to demonstrate methods for correctly calculating (1) the probability a species occupies a site given one or more non-detections, and (2) the number of sequential non-detections necessary to assert, with a pre-specified confidence, that a species is absent from a site. Location Occupancy data for a tree frog in eastern Australia serve to illustrate methods that may be applied anywhere species' occupancy data are used and detection probabilities are < 1. Methods Building on Bayesian expressions for the probability that a site is occupied by a species when it is not detected, and the number of non-detections necessary to assert absence with a pre-specified confidence, we estimate occupancy probabilities across tree frog survey locations, drawing on information about where and when the species was detected during surveys. Results We show that the number of sequential non-detections necessary to assert that a species is absent increases nonlinearly with the prior probability of occupancy, the probability of detection if present, and the desired level of confidence about absence. Main conclusions If used more widely, the Bayesian analytical approaches illustrated here would improve collection and interpretation of biological survey data, providing a coherent way to incorporate detection probability estimates in the design of minimum survey requirements for monitoring, impact assessment and distribution modelling. [ABSTRACT FROM AUTHOR]

Toe clipping reduces the return rate of some wild amphibians, but effects of toe clipping on recapture rate and survival rate (the two components of return rate) have not been quantified for salamanders. Mark-recapture data for Jefferson Salamanders (Ambystoma jeffersonianum) were analyzed to estimate these effects using eight different statistical models. These models allowed (1) the effect of removing each toe to remain constant or to increase proportionally with the number of toes removed; and (2) recapture rate and survival rate to remain constant or vary among years. The predicted effect on the return rate was similar for all eight models, with a reduction of about 15-20% when three toes were removed. The predicted effect on survival and recapture rates varied with the choice of model. The best-fitting models, as selected on the basis of the deviance information criterion, predicted a large effect on recapture rate (14-17% reduction when removing three toes) and a negligible effect on survival rate (0-2% reduction when removing three toes). Whether toe clipping reduced survival and recapture rates was unclear when the best models were selected on the basis of Bayesian P-values. The reduction in return rate of Jefferson salamanders was consistent with that previously observed for frogs and toads. However, the analysis was not able to identify clearly whether the effect was caused by a reduction in survival, a reduction in recapture rate, or both. [ABSTRACT FROM AUTHOR]

Environmental contamination contributes to the threatened status of many amphibian populations. Many contaminants alter behaviour at concentrations commonly experienced in the environment, with negative consequences for individual fitness, populations and communities. A comprehensive, quantitative evaluation of the behavioural sensitivity of amphibians is warranted to better understand the population-level and resultant ecological impacts of contaminants. We conducted a systematic review and meta-analysis evaluating behavioural changes following exposure to contaminants. Most studies were conducted in North America and Europe on larval stages, and 64% of the 116 studies focussed on the effects of insecticides. We found that a suite of contaminants influence a wide range of behaviours in amphibians, with insecticides typically invoking the strongest responses. In particular, insecticides increased rates of abnormal swimming, and reduced escape responses to simulated predator attacks. Our analysis identified five key needs for future research, in particular the need: (1) for researchers to provide more details of experimental protocols and results (2) to develop a strong research base for future quantitative reviews, (3) to broaden the suite of contaminants tested, (4) to better study and thus understand the effects of multiple stressors, and (5) to establish the ecological importance of behavioural alterations. Behavioural endpoints provide useful sub-lethal indicators of how contaminants influence amphibians, and coupled with standard ecotoxicological endpoints, can provide valuable information for population models assessing the broader ecological consequences of environmental contamination. Unlabelled Image • Chemical contamination is driving amphibian declines, often at sub-lethal concentrations. • We used meta-analysis to quantify responses to a suite of contaminants. • Contaminants caused abnormal swimming and affected escape responses. • Behaviours were typically altered in meaningful ways. • Understanding behavioural alterations help predict ecological implications. [ABSTRACT FROM AUTHOR]

Despite repeated calls to action, proposals for urban conservation are often met with surprise or scepticism. There remains a pervasive narrative in policy, practice, and the public psyche that urban environments, although useful for engaging people with nature or providing ecosystem services, are of little conservation value. We argue that the tendency to overlook the conservation value of urban environments stems from misconceptions about the ability of native species to persist within cities and towns and that this, in turn, hinders effective conservation action. However, recent scientific evidence shows that these assumptions do not always hold. Although it is generally true that increasing the size, quality, and connectivity of habitat patches will improve the probability that a species can persist, the inverse is not that small, degraded, or fragmented habitats found in urban environments are worthless. In light of these findings we propose updated messages that guide and inspire researchers, practitioners, and decision makers to undertake conservation action in urban environments: consider small spaces, recognize unconventional habitats, test creative solutions, and use science to minimize the impacts of future urban development. Article impact statement: Conserving native biodiversity is both important and achievable in urban environments. [ABSTRACT FROM AUTHOR]

Urban sprawl and the rising popularity of water‐sensitive urban design of urban landscapes has led to a global surge in the number of wetlands constructed to collect and treat stormwater runoff in cities. However, contaminants, such as heavy metals and pesticides, in stormwater adversely affect the survival, growth, and reproduction of animals inhabiting these wetlands. A key question is whether wildlife can identify and avoid highly polluted wetlands. We investigated whether pond‐breeding frogs are attempting to breed in wetlands that affect the fitness of their offspring across 67 urban wetlands in Melbourne, Australia. Frog species richness and the concentration of contaminants (heavy metals and pesticides) were not significantly related, even in the most polluted wetlands. The proportion of fringing vegetation at a wetland had the greatest positive influence on the number of frog species present and the probability of occurrence of individual species, indicating that frogs inhabited wetlands with abundant vegetation, regardless of their pollution status. These wetlands contained contaminant levels similar to urban wetlands around the world at levels that reduce larval amphibian survival. These results are, thus, likely generalizable to other areas, suggesting that urban managers could inadvertently be creating ecological traps in countless cities. Wetlands are important tools for the management of urban stormwater runoff, but their construction should not facilitate declines in wetland‐dependent urban wildlife. Article impact statement: That contaminated urban wetlands are readily occupied by frogs has implications for conservation. [ABSTRACT FROM AUTHOR]

Ex situ conservation strategies for threatened species often require long-term commitment and financial investment to achieve management objectives. We present a framework that considers the decision to adopt ex situ management for a target species as the end point of several linked decisions. We used a decision tree to intuitively represent the logical sequence of decision making. The first decision is to identify the specific management actions most likely to achieve the fundamental objectives of the recovery plan, with or without the use of ex-situ populations. Once this decision has been made, one decides whether to establish an ex situ population, accounting for the probability of success in the initial phase of the recovery plan, for example, the probability of successful breeding in captivity. Approaching these decisions in the reverse order (attempting to establish an ex situ population before its purpose is clearly defined) can lead to a poor allocation of resources, because it may restrict the range of available decisions in the second stage. We applied our decision framework to the recovery program for the threatened spotted tree frog (Litoria spenceri) of southeastern Australia. Across a range of possible management actions, only those including ex situ management were expected to provide >50% probability of the species' persistence, but these actions cost more than use of in situ alternatives only. The expected benefits of ex situ actions were predicted to be offset by additional uncertainty and stochasticity associated with establishing and maintaining ex situ populations. Naïvely implementing ex situ conservation strategies can lead to inefficient management. Our framework may help managers explicitly evaluate objectives, management options, and the probability of success prior to establishing a captive colony of any given species. [ABSTRACT FROM AUTHOR]

Anthropogenic climate change is a key threat to global biodiversity. To inform strategic actions aimed at conserving biodiversity as climate changes, conservation planners need early warning of the risks faced by different species. The IUCN Red List criteria for threatened species are widely acknowledged as useful risk assessment tools for informing conservation under constraints imposed by limited data. However, doubts have been expressed about the ability of the criteria to detect risks imposed by potentially slow-acting threats such as climate change, particularly because criteria addressing rates of population decline are assessed over time scales as short as 10 years. We used spatially explicit stochastic population models and dynamic species distribution models projected to future climates to determine how long before extinction a species would become eligible for listing as threatened based on the IUCN Red List criteria. We focused on a short-lived frog species (Assa darlingtoni) chosen specifically to represent potential weaknesses in the criteria to allow detailed consideration of the analytical issues and to develop an approach for wider application. The criteria were more sensitive to climate change than previously anticipated; lead times between initial listing in a threatened category and predicted extinction varied from 40 to 80 years, depending on data availability. We attributed this sensitivity primarily to the ensemble properties of the criteria that assess contrasting symptoms of extinction risk. Nevertheless, we recommend the robustness of the criteria warrants further investigation across species with contrasting life histories and patterns of decline. The adequacy of these lead times for early warning depends on practicalities of environmental policy and management, bureaucratic or political inertia, and the anticipated species response times to management actions. Detección del Riesgo de Extinción a partir del Cambio Climático por medio del Criterio de la Lista Roja de la UICNKeith et al. [ABSTRACT FROM AUTHOR]

Highlights: [•] Bayesian Networks can predict how social and ecological factors influence biodiversity. [•] Faunal gains are greatest when cleared areas are restored compared with remnant and revegetated habitat. [•] Cost-effective management actions differ between habitats and faunal groups. [•] Landholder demographics can influence habitat variables and faunal species richness. [•] Current restoration actions may not increase faunal species in agricultural areas. [Copyright &y& Elsevier]

Spatio-temporal studies of hybrid zones provide an opportunity to test evolutionary hypotheses of hybrid zone maintenance and movement. We conducted a landscape genetics study on a classic hybrid zone of the south-eastern Australian frogs, Litoria ewingii and Litoria paraewingi. This hybrid zone has been comprehensively studied since the 1960s, providing the unique opportunity to directly assess changes in hybrid zone structure across time. We compared both mtDNA and male advertisement call data from two time periods (present and 1960s). Clinal analysis of the coincidence (same center) and concordance (same width) of these traits indicated that the center of the hybrid zone has shifted 1 km south over the last 40 years, although the width of the zone and the rate of introgression remained unchanged. The low frequency of hybrids, the strong concordance of clines within a time period, and the small but significant movement across the study period despite significant anthropogenic changes through the region, suggest the hybrid zone is a tension zone located within a low-density trough. Hybrid zone movement has not been considered common in the past but our findings highlight that it should be considered a crucial component to our understanding of evolution. [ABSTRACT FROM AUTHOR]

Plant and animal survey detection rates are important for ecological surveys, environmental impact assessment, invasive species monitoring, and modeling species distributions. Species can be difficult to detect when rare but, in general, how detection probabilities vary with abundance is unknown. We developed a new detectability model based on the time to detection of the first individual of a species. Based on this model, the predicted detection rate is proportional to a power function of abundance with a scaling exponent between zero and one that depends on clustering of individuals. We estimated the model parameters with data from three independent datasets: searches for chenopod shrub species and coins, experimental searches for planted seedlings, and frog surveys at multiple sites in sub-tropical forests of eastern Australia. Analyses based on the detection time and detection probability suggest that detection rate increases with abundance as predicted. The model provides a way to scale detection rates to cases of low abundance when direct estimation of detection rates is often impractical. [ABSTRACT FROM AUTHOR]

Aim Population viability analysis ( PVA) is used to quantify the risks faced by species under alternative management regimes. Bayesian PVAs allow uncertainty in the parameters of the underlying population model to be easily propagated through to the predictions. We developed a Bayesian stochastic patch occupancy model ( SPOM) and used this model to assess the viability of a metapopulation of the growling grass frog ( Litoria raniformis) under different urbanization scenarios. Location Melbourne, Victoria, Australia. Methods We fitted a Bayesian model that accounted for imperfect detection to a multiseason occupancy dataset for L. raniformis collected across northern Melbourne. The probability of extinction was modelled as a function of effective wetland area, aquatic vegetation cover and connectivity, using logistic regression. The probability of colonization was modelled as a function of connectivity alone. We then simulated the dynamics of a metapopulation of L. raniformis subject to differing levels of urbanization and compensatory wetland creation. Uncertainty was propagated by conducting simulations for 5000 estimates of the parameters of the models for extinction and colonization. Results There was considerable uncertainty in both the probability of quasi-extinction and the minimum number of occupied wetlands under most urbanization scenarios. Uncertainty around the change in quasi-extinction risk and minimum metapopulation size increased with increasing habitat loss. For our focal metapopulation, the analysis revealed that significant investment in new wetlands may be required to offset the impacts of urbanization. Main conclusions Bayesian approaches to PVA allow parametric uncertainty to be propagated and considered in management decisions. They also provide means of identifying parameters that represent critical uncertainties, and, through the use of informative priors, can easily assimilate new data to reduce parametric uncertainty. These advantages, and the ready availability of software to run Bayesian analyses, will ensure that Bayesian approaches are used increasingly for PVAs. [ABSTRACT FROM AUTHOR]