ORCID Profile
0000-0001-6737-7468
Current Organisation
University of Tasmania
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.ENVINT.2018.07.019
Abstract: Predicting future food demand is a critical step for formulating the agricultural, economic and conservation policies required to feed over 9 billion people by 2050 while doing minimal harm to the environment. However, published future food demand estimates range substantially, making it difficult to determine optimal policies. Here we present a systematic review of the food demand literature-including a meta-analysis of papers reporting average global food demand predictions-and test the effect of model complexity on predictions. We show that while estimates of future global kilocalorie demand have a broad range, they are not consistently dependent on model complexity or form. Indeed, time-series and simple income-based models often make similar predictions to integrated assessments (e.g., with expert opinions, future prices or climate influencing forecasts), despite having different underlying assumptions and mechanisms. However, reporting of model accuracy and uncertainty was uncommon, leading to difficulties in making evidence-based decisions about which forecasts to trust. We argue for improved model reporting and transparency to reduce this problem and improve the pace of development in this field.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 28-08-2020
Abstract: The late Quaternary paleorecord, within the past ∼130,000 years, can help to inform present-day management of the Earth's ecosystems and biota under climate change. Fordham et al. review when and where rapid climate transitions can be found in the paleoclimate record. They show how such events in Earth's history can shape our understanding of the consequences of future global warming, including rates of bio ersity loss, changes in ecosystem structure and function, and degradation in the goods and services that these ecosystems provide to humanity. They also highlight how recent developments at the intersection of paleoecology, paleoclimatology, and macroecology can provide opportunities to anticipate and manage the responses of species and ecosystems to changing climates in the Anthropocene. Science , this issue p. eabc5654
Publisher: Informa UK Limited
Date: 23-09-2022
Publisher: Wiley
Date: 28-09-2021
Abstract: Spatially explicit population models (SEPMs) can simulate spatiotemporal changes in species' range dynamics in response to variation in climatic and environmental conditions, and anthropogenic activities. When combined with pattern‐oriented modelling methods, ecological processes and drivers of range shifts and extinctions can be identified, and plausible chains of causality revealed. The open‐source multi‐platform R package poems provides functionality for simulating and validating projections of species' range dynamics using stochastic, lattice‐based population models. Built‐in modules allow parameter uncertainty to propagate through to model simulations, with their effects on species' range dynamics evaluated using Approximate Bayesian Computation. These validation procedures identify models with the structural complexity and parameterisation needed to simulate the effects of past changes in climate, environment and human activities on species' range shifts and extinction risk. We illustrate the features and versatility of poems by simulating the historical decline and extinction of the Thylacine Thylacinus cynocephalus , an icon of recent extinctions in Australia. We show that poems can reveal likely ecological pathways to extinction using pattern‐oriented methods, providing validated projections of the range collapse and population decline of threatened species. By providing flexible and extendable modules for building and validating SEPMs of species' range dynamics, poems allows the effects of past and future threats on species' populations to be quantified using well‐parameterised, structurally realistic models, with important generative mechanisms. Since poems can directly unravel ecological processes of species responses to global change, and strengthen predictions of range shifts and extinction risk—within a flexible, R‐based environment—we anticipate that poems will be of significant value to ecologists, conservation managers and biogeographers.
Publisher: Cold Spring Harbor Laboratory
Date: 09-2021
DOI: 10.1101/2021.08.31.458457
Abstract: Despite the increasing interest in developing new bioregionalizations and assessing the most widely accepted biogeographic frameworks, no study to date has sought to systematically define a system of small bioregions nested within larger ones that better reflect the distribution and patterns of bio ersity. Here, we examine how an algorithmic, data-driven model of ersity patterns can lead to an ecologically interpretable hierarchy of bioregions. Australia. Present. Terrestrial vertebrates and vascular plants. We compiled information on the biophysical characteristics and species occupancy of Australia’s geographic conservation units (bioregions). Then, using cluster analysis to identify groupings of bioregions representing optimal discrete-species areas, we evaluated what a hierarchical bioregionalization system would look like when based empirically on the within-and between-site ersity patterns across taxa. Within an information-analytical framework, we then assessed the degree to which the World Wildlife Fund’s (WWF) biomes and ecoregions and our suite of discrete-species areas are spatially associated and compared those results among bioregionalization scenarios. Information on bio ersity patterns captured was moderate for WWF’s biomes (50– 58% for birds’ beta, and plants’ alpha and beta ersity, of optimal discrete areas, respectively) and ecoregions (additional 4–25%). Our plants and vertebrate optimal areas retained more information on alpha and beta ersity across taxa, with the two algorithmically derived biogeographic scenarios sharing 86.5% of their within- and between-site ersity information. Notably, discrete-species areas for beta ersity were parsimonious with respect to those for alpha ersity. Nested systems of bioregions must systematically account for the variation of species ersity across taxa if bio ersity research and conservation action are to be most effective across multiple spatial or temporal planning scales. By demonstrating an algorithmic rather than subjective method for defining bioregionalizations using species- ersity concordances, which reliably reflects the distributional patterns of multiple taxa, this work offers a valuable new tool for systematic conservation planning.
Publisher: Informa UK Limited
Date: 12-07-2021
Publisher: Informa UK Limited
Date: 30-06-2020
Publisher: Cold Spring Harbor Laboratory
Date: 12-08-2023
DOI: 10.1101/2023.08.08.552370
Abstract: Southeast Asia is highly bio erse and currently experiences among the highest rates of tropical deforestation globally, but impacts on bio ersity are not well synthesized. We use Bayesian multi-level modeling to meta-analyse 831 pairwise comparisons of bio ersity in sites subject to human land use change and anthropogenic forest disturbance (for ex le in plantations or logged forest) versus undisturbed sites. After controlling for hierarchical dependences, we show that bio ersity is a fifth lower in sites with these land-use changes (95% credible interval= 16-28%, mean = 22%). This reduction was greater when land use change/anthropogenic forest disturbances were high-intensity (34% reduction in bio ersity) compared to low-intensity (18% reduction), and effects were consistent across biogeographic regions and taxa. Oil-palm plantations lead to the greatest reduction in bio ersity (39%, CI 27-48%), and agroforests the least (24%, CI 10-37%). We also find that bio ersity is reduced in young secondary forest by 26% (CI 4-42%) compared to undisturbed forest, but there is no reduction in bio ersity for intermediate or mature-aged secondary forest (although species composition is potentially altered). Overall, our study provides the clearest evidence yet of the substantial detrimental impact of land-use change and anthropogenic forest disturbance on the bio ersity of Southeast Asia.
Publisher: Authorea, Inc.
Date: 28-08-2023
DOI: 10.22541/AU.169321871.15706342/V1
Abstract: Wildlife monitoring is a crucial component of conservation management, with reliable field surveys being important for trend analysis and population viability modelling. Unoccupied aircraft systems (UAS), also known as drones, are rapidly supplanting manned aircraft for aerial wildlife counts. Here we investigated and compared the impacts of drone presence on two large terrestrial mammals from Tasmania, Australia—Bennett’s wallaby ( Notamacropus rufogriseus ), and Forester kangaroo ( Macropus giganteus tasmaniensis ) —using a commercial quadcopter model: DJI Phantom 4 Pro. Further, a ground bird, the domestic chicken ( Gallus gallus domesticus ), was used as a model organism to further investigate behavioural responses of ‘aerial aware’ species to drones. We found that M. giganteus tasmaniensis and N. rufogriseus started to exhibit noticeable changes in behaviour, including evasion, when the drone motor sound exceeded ~50 decibels (dB) as heard from the ground (at flight altitudes of 30 – 50 m). At lower sound levels (48 dB and below, above 50 m), the animal’s response was minimal. The response of G. gallus domesticus to the drone was remarkably similar to that of the Macropus species, despite the species generally being more susceptible to, and instinctively vigilant against drone-sized aerial predators such as raptors. This study has established the baseline information required to understand the limits of drone operations, in terms of target disturbance, for macropod surveys.
Publisher: Informa UK Limited
Date: 02-07-2020
Publisher: The Royal Society
Date: 26-10-2022
Abstract: Scavenging by large carnivores is integral for ecosystem functioning by limiting the build-up of carrion and facilitating widespread energy flows. However, top carnivores have declined across the world, triggering trophic shifts within ecosystems. Here, we compare findings from previous work on predator decline against areas with recent native mammalian carnivore loss. Specifically, we investigate top-down control on utilization of experimentally placed carcasses by two mesoscavengers—the invasive feral cat and native forest raven. Ravens profited most from carnivore loss, scavenging for five times longer in the absence of native mammalian carnivores. Cats scavenged on half of all carcasses in the region without dominant native carnivores. This was eight times more than in areas where other carnivores were at high densities. All carcasses persisted longer than the three-week monitoring period in the absence of native mammalian carnivores, while in areas with high carnivore abundance, all carcasses were fully consumed. Our results reveal that top-carnivore loss lifies impacts associated with carnivore decline—increased carcass persistence and carrion access for smaller scavengers. This suggests that even at low densities, native mammalian carnivores can fulfil their ecological functions, demonstrating the significance of global carnivore conservation and supporting management approaches, such as trophic rewilding.
Publisher: Public Library of Science (PLoS)
Date: 20-07-2018
Publisher: Cold Spring Harbor Laboratory
Date: 19-01-2021
DOI: 10.1101/2021.01.18.427207
Abstract: The spatial analysis of linear features (lines and curves) is a challenging and rarely attempted problem in ecology. Existing methods are typically expressed in abstract mathematical formalism, making it difficult to assess their relevance and transferability into an ecological setting. A set of concrete and accessible tools is needed. We develop a new method to analyse the spatial patterning of line-segment data. It is based on a generalisation of Ripley’s K -function and includes an analogue of the transformed L -function, together with estimators and theoretical expectation values. We introduce a class of line-segment processes, related to the Boolean model, which we use in conjunction with Monte-Carlo methods and information criteria to generate and compare candidate models. We demonstrate the utility of our method using fallen tree (dead log) data collected from two one-hectare Australian tall eucalypt forest plots. Comparing six line-segment models, we find for both plots that the distribution of fallen logs is best explained by plot-level spatial heterogeneity. The use of non-uniform distributions to model dead-log orientation on the forest floor improves model performance in one of the two sites. Our case study highlights the challenges of model comparison in spatial-pattern analysis, where Monte-Carlo approaches based on the discrepancy of simulated summary functions can generate a different ranking of models than that of information criteria. These methods are of a general nature and are applicable to any line-segment data. In the context of forest ecology, the integration of fallen logs as linear structural features in a landscape with the point locations of living trees, and a quantification of their interactions, will yield new insights into the functional and structural role of tree fall in forest communities and their enduring post-mortem ecological legacy as spatially distributed decomposing logs.
Publisher: Wiley
Date: 08-2018
DOI: 10.1111/COBI.13186
Publisher: Springer Science and Business Media LLC
Date: 20-06-2018
Publisher: Cold Spring Harbor Laboratory
Date: 19-02-2021
DOI: 10.1101/2021.02.18.429855
Abstract: Global road networks facilitate habitat modification and are integral to human expansion. Many animals, particularly scavengers, use roads as they provide a reliable source of food, such as carrion left after vehicle collisions. Tasmania is often cited as the ‘roadkill capital of Australia’, with the isolated offshore islands in the Bass Strait experiencing similar, if not higher, levels of roadkill. However, native mammalian predators on the islands are extirpated, meaning the remaining scavengers are likely to experience lower interference competition. In this study, we use a naturally occurring experiment to examine how the loss of mammalian carnivores within a community impacts roadside foraging behaviour by avian scavengers. We monitored the locations of roadkill and forest ravens ( Corvus tasmanicus ), an abundant scavenger species, on eight road transects across the Tasmanian mainland (high scavenging competition) and the Bass Strait islands (low scavenging competition). We represented raven observations as one-dimensional point patterns, using hierarchical Bayesian models to investigate the dependence of raven spatial intensity on habitat, season, distance to roadkill and route location. We found that roadkill carcasses were a strong predictor of raven presence along road networks. The effect of roadkill was lified on roads on the Bass Strait islands, where roadside carrion was a predictor of raven presence across the entire year. In contrast, ravens were more often associated with roadkill on Tasmanian mainland roads in the autumn, when other resources were low. This suggests that in the absence of competing mammalian scavengers, ravens choose to feed on roadside carrion throughout the year, even in seasons when other resources are available. This low interference competition could be disproportionately benefiting forest ravens, leading to augmented raven populations and changes to the vertebrate community structure. Our study provides evidence that scavengers modify their behaviour in response to reduced scavenger species ersity, potentially triggering trophic shifts and highlighting the importance of conserving or reintroducing carnivores within ecosystems.
Publisher: CSIRO Publishing
Date: 15-03-2022
DOI: 10.1071/ZO21037
Abstract: Deriving estimates of demographic parameters and the processes driving them is crucial for identifying wildlife management options. The short-beaked echidna (Tachyglossus aculeatus) is the most widely distributed native Australian mammal, yet little is known of its population dynamics due to its cryptic nature. Consequently, assessment of the impacts of climate and threats on echidna populations has been difficult. We analyse 19 years (1996–2014) of mark–recapture data to estimate survival and reproductive rates of a Tasmanian population of short-beaked echidna, and to evaluate the influence of regional weather patterns on its demographics. Population size showed high year-to-year variation, ranging from 1 to 40 echidnas km2 across the study area. Known-fate modelling of radio-tracked in iduals suggested that climatic conditions impacted survival average longevity was estimated at 16.7 years but only 4.8 years when the total spring/summer rainfall was below 125 mm, and 6.25 in years when temperatures more frequently exceeded 32°C. Recruitment, estimated from Pradel analyses, was low in the population (β = 0.08) and not significantly affected by climate. These results are the first quantitative estimates of climate effects, survival, and recruitment for this species, and suggest that climate-enhanced drying and temperature increase would pose a threat to echidna populations in Tasmania.
Publisher: MDPI AG
Date: 16-04-2019
DOI: 10.3390/F10040340
Abstract: The relative abundance of nitrogen-fixing species has been hypothesised to influence tree biomass, decomposition, and nitrogen availability in eucalypt forests. This prediction has been demonstrated in experimental settings (two-species mixtures) but is yet to be observed in the field with more realistically complex communities. We used a combination of (a) field measurements of tree-community composition, (b) s ling of soil from a subset of these sites (i.e., the local environment), and (c) a decomposition experiment of forest litter to examine whether there is a local-scale effect of the nitrogen-fixing Acacia dealbata Link (presence and abundance) on nitrogen availability, and whether increases in this essential nutrient led to greater biomass of the canopy tree species, Eucalyptus obliqua L’Hér. Average A. dealbata tree size was a significant predictor of forest basal area in 24 plots (12% deviance explained) and, when combined with average distance between trees, explained 29.1% variance in E. obliqua biomass. However, static patterns of local nitrogen concentration were unrelated to the presence or size of A. dealbata, despite our experiments showing that A. dealbata leaf litter controls decomposition rates in the soil (due to three times higher N). Such results are important for forest management in the context of understanding the timing and turnover of shorter-lived species like acacias, where higher N (through either litter or soil) might be better detected early in community establishment (when growth is faster and intraspecific competition more intense) but with that early signal subsequently dissipated.
Publisher: Wiley
Date: 09-2016
Publisher: Frontiers Media SA
Date: 22-10-2020
Publisher: Springer Science and Business Media LLC
Date: 29-11-2020
Publisher: American Association for the Advancement of Science (AAAS)
Date: 21-04-2017
Abstract: Bio ersity is essential to human well-being, but people have been reducing bio ersity throughout human history. Loss of species and degradation of ecosystems are likely to further accelerate in the coming years. Our understanding of this crisis is now clear, and world leaders have pledged to avert it. Nonetheless, global goals to reduce the rate of bio ersity loss have mostly not been achieved. However, many ex les of conservation success show that losses can be halted and even reversed. Building on these lessons to turn the tide of bio ersity loss will require bold and innovative action to transform historical relationships between human populations and nature.
Publisher: MDPI AG
Date: 17-04-2017
DOI: 10.3390/F8040123
Publisher: Cold Spring Harbor Laboratory
Date: 21-04-2021
DOI: 10.1101/2021.04.20.440554
Abstract: Conserving nomadic species is challenging due to the difficulty in monitoring their characteristically transient populations, and thereby detecting range-wide declines. An ex le is the Yellow-tailed Black-Cockatoo (YTBC Zanda funerea ), which disperses widely in search of food and is regularly—but sporadically—observed across eastern Australia. Under climate warming, a general southward shift in species distributions is expected in the southern hemisphere, with the extreme southern margins being truncated by an ocean barrier. Given these constraints, we ask whether sufficient refugia will exist for the YTBC in the future, by: (i) modelling habitat relationships within current geographic range of the YTBC based on weather, climate, vegetation, and land use, and (ii) using this framework, coupled with climate-model projections, to forecast 21 st century impacts. Intensive land use and high variability in temperature and rainfall seem to most limit YTBC occurrence. In contrast, areas with a cooler, stable climate, and a network of old-growth forests, such as occurs in parts of south-eastern Australia and Tasmania, are most suitable for the species. As Australia becomes progressively hotter under climate change, the preferred bioclimatic envelope of the YTBC is forecast to contract poleward (as a general pattern) and to fragment within the existing range. However, despite an extensive loss of climatically suitable regions, the YTBC might find stable refugia at the southern margins of its geographic range, although continued loss of old-growth forests undermines their nesting potential. Therefore, beyond habitat conservation, creating nesting opportunities within plantation forests would likely be an effective conservation strategy to preserve habitat quality in climate refugia.
Publisher: Cold Spring Harbor Laboratory
Date: 21-01-2021
DOI: 10.1101/2021.01.20.427508
Abstract: With thousands of vertebrate species now threatened with extinction, there is an urgent need to understand and mitigate the causes of wildlife collapse. As distinct evolutionary clades can follow different routes to endangerment, there is value in taxon-specific analyses when assessing species’ vulnerability to threats and identifying gaps in conservation actions. Rails (Aves: Rallidae), being the most extinction-prone bird Family globally, and with one third of extant rail species now threatened or near-threatened, are an emphatic case in point. Yet even for this well-studied group, there is uncertainty in our understanding of what factors might be causing this vulnerability, whether the current threats are consistent with those that led to recent extinctions, and ultimately, what conservation actions might be necessary to mitigate further losses. Here, we undertook a global synthesis of the temporal and spatial threat patterns for Rallidae and determined conservation priorities and gaps. We found two key pathways in the threat pattern for rails. One follows the same trajectory as extinct rails, where island endemic and flightless rails are most threatened, mainly due to invasive predators. The second, created by the recent ersification of anthropogenic activities, involves continental rails (generally in the Neotropics), threatened most commonly by agriculture, natural-system modifications and residential and commercial development. Conservation efforts around most-at-risk species should be adapted according to the most relevant geographic scale (bioregions or countries), and principal locality type of the population (continental or island endemic). Indonesia, the U.S.A., the United Kingdom, New Zealand, and Cuba were the priority countries identified by our classification system incorporating species’ unique evolutionary features and level of endangerment, but also among the countries that lack conservation actions the most. Future efforts should predominantly target improvements in ecosystem protection and management, as well as ongoing research and monitoring. Forecasting the impacts of climate change on island endemic rails and disentangling the specific roles of extrinsic and intrinsic traits (like flightlessness), will be particularly valuable avenues of research for improving our forecasts of rail vulnerability.
Publisher: Cold Spring Harbor Laboratory
Date: 06-09-2021
DOI: 10.1101/2021.09.06.459188
Abstract: Scavenging by large carnivores is integral for ecosystem functioning by limiting the build-up of carrion and facilitating widespread energy flows. However, top carnivores have declined across the world, triggering trophic shifts within ecosystems. In this study, we use a natural ‘removal experiment’ of disease-driven decline and island extirpation of native mammalian (marsupial) carnivores to investigate top-down control on utilisation of experimentally placed carcasses by two mesoscavengers – the invasive feral cat and native forest raven. Ravens were the main beneficiary of carnivore loss, scavenging for five times longer in the absence of native mammalian carnivores. Cats scavenged on almost half of all carcasses in the region without dominant native carnivores. This was eight times more than in areas where other carnivores were at high densities. In the absence of native mammalian carnivores, all carcasses persisted in the environment for 3 weeks. Our results reveal the efficiency of carrion consumption by mammalian scavengers. These services are not readily replaced by less-efficient facultative scavengers. This demonstrates the significance of global carnivore conservation and supports novel management approaches, such as rewilding in areas where the natural suite of carnivores is missing.
Publisher: Wiley
Date: 21-10-2022
DOI: 10.1002/PAN3.10410
Abstract: Palaeontological animal bone deposits are rarely investigated through research partnerships where the local First Nations communities have a defining hand in both the research questions asked and the research processes. Here we report research undertaken through such a partnership approach at the iconic archaeological site of Cloggs Cave (GunaiKurnai Country, East Gippsland), in the southern foothills of SE Australia's Great Dividing Range. A new excavation was combined with detailed chronometric dating, high‐resolution 3D mapping and geomorphological studies. This allowed interpretation of a sequence of stratigraphic layers spanning from a lowermost excavated mixed layer dated to between 25,640 and 48,470 cal BP, to a dense set of uppermost, ash layers dated to between 1460 and 3360 cal BP. This long and well‐dated chronostratigraphic sequence enabled temporal trends in the abundant small mammal remains to be examined. The fossil assemblage consists of at least 31 taxa of mammals which change in proportions through time. Despite clear evidence that the Old Ancestors repeatedly carried vegetation into the cave to fuel cool fires (no visible vegetation grows in Cloggs Cave), we observed little to no evidence of cooking fires or calcined bone, suggesting that people had little involvement with the accumulation of the faunal remains. Small mammal bones were most likely deposited in the cave by large disc‐faced owls, Tyto novaehollandae (Masked Owl) or Tyto tenebricosa (Sooty Owl). Despite being well dated and largely undisturbed, the Cloggs Cave assemblage does not appear to track known Late Quaternary environmental change. Instead, the complex geomorphology of the area fostered a vegetation mosaic that supported mammals with ergent habitat preferences. The faunal deposit suggests a local ancestral landscape characterised by a resilient mosaic of habitats that persisted over thousands of years, signalling that the Old Ancestors burned landscape fires to encourage and manage patches of different vegetation types and ages within and through periods of climate change. Read the free Plain Language Summary for this article on the Journal blog.
Publisher: Cold Spring Harbor Laboratory
Date: 19-01-2021
DOI: 10.1101/2021.01.18.427214
Abstract: Like the Dodo and Passenger Pigeon before it, the predatory marsupial Thylacine ( Thylacinus cynocephalus ), or ‘Tasmanian tiger’, has become an iconic symbol of human-caused extinction. The last captive animal died in 1936, but even today reports of the Thylacine’s possible ongoing survival in remote regions of Tasmania are newsworthy and capture the public’s imagination. Extirpated from mainland Australia in the mid-Holocene, the large island of Tasmania became the species’ final stronghold. Following European settlement in the 1800s, the Thylacine was heavily persecuted and pushed to the margins of its range, although many sightings were reported thereafter—even well beyond the 1930s. To gain a new depth of insight into the extinction of the Thylacine, we assembled an exhaustive database of 1,237 observational records from Tasmania (from 1910 onwards), quantified their uncertainty, and charted the patterns these revealed. We also developed a new method to visualize the species’ 20 th -century spatio-temporal dynamics, to map potential post-bounty refugia and pinpoint the most-likely location of the final persisting subpopulation. A direct reading of the high-quality records (confirmed kills and captures, in combination with sightings by past Thylacine hunters and trappers, wildlife professionals and experienced bushmen) implies a most-likely extinction date within four decades following the last capture (i.e., 1940s to 1970s). However, uncertainty modelling of the entire sighting record, where each observation is assigned a probability and the whole dataset is then subject to a sensitivity analysis, suggests that extinction might have been as recent as the late 1980s to early 2000s, with a small chance of persistence in the remote south-western wilderness areas. Beyond the intrinsically fascinating problem of reconstructing the final fate of the Thylacine, the new spatio-temporal mapping of extirpation developed herein would also be useful for conservation prioritization and search efforts for other rare taxa of uncertain status.
Publisher: Springer Science and Business Media LLC
Date: 03-01-2022
Publisher: Elsevier BV
Date: 04-2019
Publisher: Authorea, Inc.
Date: 25-05-2023
DOI: 10.22541/AU.168502324.42187548/V1
Abstract: As a source of information on species’ geographic distributions, macroecologists and biogeographers have had to rely on expert-derived range maps to study bio ersity patterns at large scales. In addition to being biased towards well-studied taxa and subjective by nature, such maps suffer from a lack of consistency in how species’ absences are treated within the wider distribution. Using the finer resolution of the Interim Biogeographic Regionalization for Australia (subregions) and ex le sets of Australian species as study system, we developed a reproducible, data-driven approach to map the extent of occurrence (EOO) of hundreds—or even thousands—of species by combining presence-only data and subregions (i.e., non-equal-sized operational units that represent homogenous areas of unique environmental features) within a unifying quantitative framework. From data-driven and expert-derived range maps for 533 birds, species richness’ estimates differ at three biogeographical scales—whit bias (mean error) at coarser resolution (ecoregion) being half that at subregional scale—and the spatial association between pairs of these birds’ presence-absence maps vary from nearly zero to almost one (representing such pattern almost either differently or identically, respectively). Holes within the wider distribution of the EOO maps for pairs of hibians, mammals, reptiles, and plants seem to respond to the demarcation of different subpopulations over Australia rather than causing an underestimation of a species’ empirical distribution. These results demonstrate that this approach can reliably map EOO of species whose distributions aligns with three broad types of geographic patterns (wide-range, habitat-specialists, and range-restricted species). This alternative to expert-derived range maps can serve as a basis for more robust, data-driven studies of biogeographic bio ersity patterns, thus improving our understanding and conservation efforts of global bio ersity.
Publisher: Wiley
Date: 07-06-2021
Abstract: Global road networks facilitate habitat modification and are integral to human expansion. Many animals, particularly scavengers, use roads as they provide a reliable source of food, such as carrion left after vehicle collisions. Tasmania is often cited as the ‘roadkill capital of Australia’, with the isolated offshore islands in the Bass Strait experiencing similar, if not higher, levels of roadkill. However, native mammalian predators on the islands are extirpated, meaning the remaining scavengers are likely to experience lower interference competition. In this study, we used a naturally occurring experiment to examine how the loss of mammalian carnivores within a community impacts roadside foraging behaviour by avian scavengers. We monitored the locations of roadkill and forest ravens Corvus tasmanicus , an abundant scavenger species, on eight road transects across the Tasmanian mainland (high scavenging competition) and the Bass Strait islands (low scavenging competition). We represented raven observations as one‐dimensional point patterns, using hierarchical Bayesian models to investigate the dependence of raven spatial intensity on habitat, season, distance to roadkill and route location. We found that roadkill carcasses were a strong predictor of raven presence along road networks. The effect of roadkill was lified on roads on the Bass Strait islands, where roadside carrion was a predictor of raven presence across the entire year. In contrast, ravens were more often associated with roadkill on Tasmanian mainland roads in the autumn, when other resources were low. This suggests that in the absence of competing mammalian scavengers, ravens choose to feed on roadside carrion throughout the year, even in seasons when other resources are available. This lack of competition could be disproportionately benefiting forest ravens, leading to augmented raven populations and changes to the vertebrate community structure. Our study provides evidence that scavengers modify their behaviour in response to reduced scavenger species ersity, potentially triggering trophic shifts and highlighting the importance of conserving or reintroducing carnivores within ecosystems.
Publisher: Oxford University Press
Date: 21-12-2017
DOI: 10.1093/OSO/9780198808978.003.0008
Abstract: This chapter critically evaluates the likelihood that planet Earth will cross one or more global environmental tipping points, resulting in a degraded state that would be difficult to reverse. Ecological tipping points occur when components of a system change rapidly due an initial forcing that is lified by positive feedbacks, resulting in a regime shift. The chapter examines the evidence in support of biological and geophysical boundaries that clearly delimit a “safe operating space” for people and bio ersity. For in idual ecosystems, abrupt state transitions have been documented. However, apart from the climate system, there is scant evidence (or theoretical justification) to support the view that global aggregates like bio ersity, chemical cycles, or resource extraction have planetary thresholds that define the boundaries of a global safe operating space. Acknowledging the absence of clear evidence for thresholds or boundaries at the global level does not diminish the seriousness of anthropogenic impacts. It does, however, imply that local-scale mitigation actions will be most effective.
Publisher: Elsevier BV
Date: 07-2020
Publisher: The Royal Society
Date: 09-2021
DOI: 10.1098/RSOS.210262
Abstract: With thousands of vertebrate species now threatened with extinction, there is an urgent need to understand and mitigate the causes of wildlife collapse. Rails (Aves: Rallidae), being the most extinction-prone bird family globally, and with one-third of extant rail species now threatened or near threatened, are an emphatic case in point. Here, we undertook a global synthesis of the temporal and spatial threat patterns for Rallidae and determined conservation priorities and gaps. We found two key pathways in the threat pattern for rails. One follows the same trajectory as extinct rails, where island endemic and flightless rails are most threatened, mainly due to invasive predators. The second, created by the ersification of anthropogenic activities, involves continental rails, threatened mainly by agriculture, natural system modifications, and residential and commercial development. Indonesia, the USA, the United Kingdom, New Zealand and Cuba were the priority countries identified by our framework incorporating species' uniqueness and the level of endangerment, but also among the countries that lack conservation actions the most. Future efforts should predominantly target improvements in ecosystem protection and management, as well as ongoing research and monitoring. Forecasting the impacts of climate change on island endemic rails will be particularly valuable to protect rails.
Publisher: MDPI AG
Date: 06-06-2021
DOI: 10.3390/ANI11061691
Abstract: Causative disease and stress agents which manifest as dermatitis in mammals have varying effects on in idual animals, from benign irritation and inflammation, to causing morbidity and even mortality. Bacteria, viruses and ectoparasites are all potential causes of dermatitis, and it can be exacerbated by various environmental, genetic and social factors. Furthermore, it is uncertain whether dermatitis is more likely to manifest in already-vulnerable wildlife species. Here, we systematically review the literature for reports of dermatitis in terrestrial and semi-aquatic wild mammalian species, with the goal of determining the biogeographical scale of dermatitis reports, the causes of dermatitis, and whether manifestation of dermatitis is reported more commonly in certain wildlife species or their captivity status (i.e., free-living, in captivity or in a laboratory). We reveal biases in the reporting of dermatitis by a biogeographic realm, with 55% of cases reported in the Nearctic, and towards particular orders of mammals, namely Artiodactyla and Carnivora. Overall, free-living wildlife is almost twice as likely to be reported as having dermatitis than in iduals in captivity and six times more likely than in iduals in laboratories, which we interpret as owing to exposure to a broader spectrum of parasites in free-ranging in iduals, and potential reporting bias in captive in iduals. Notably, dermatitis was reported in 23 threatened species, with some species more likely than others to be reported exhibiting clinical signs of dermatitis resulting from underlying health problems. We also find that threatened species are more likely to be reported as having dermatitis in captivity, particularly outside of their endemic home range. This review highlights erse patterns of dermatological disease causes in captive and free-ranging wildlife, conditions under which they are more likely to be documented, and the need for cross-disciplinary research to ascertain (and so better manage) the varied causes.
Publisher: Wiley
Date: 16-05-2018
DOI: 10.1002/ECY.2215
Abstract: The spatial analysis of dimensionless points (e.g., tree locations on a plot map) is common in ecology, for instance using point-process statistics to detect and compare patterns. However, the treatment of one-dimensional linear features (fiber processes) is rarely attempted. Here we appropriate the methods of vector sums and dot products, used regularly in fields like astrophysics, to analyze a data set of mapped linear features (logs) measured in 12 × 1-ha forest plots. For this demonstrative case study, we ask two deceptively simple questions: do trees tend to fall downhill, and if so, does slope gradient matter? Despite noisy data and many potential confounders, we show clearly that topography (slope direction and steepness) of forest plots does matter to treefall. More generally, these results underscore the value of mathematical methods of physics to problems in the spatial analysis of linear features, and the opportunities that interdisciplinary collaboration provides. This work provides scope for a variety of future ecological analyzes of fiber processes in space.
Publisher: Wiley
Date: 09-2019
DOI: 10.1002/ECS2.2859
Abstract: Expanding the reserve system is a key strategy to enhance bio ersity protection. Yet, conservation outcomes can be undermined by underrepresentation of some habitats and opportunistic placement of protected areas. Irreplaceability and vulnerability, the key principles of conservation, should thus be combined within a bioregionalization framework to implement protection in the habitats that most need it. We proposed a simple and flexible method to prioritize bioregions for conservation based on these principles and used it to rank the 85 bioregions of the Australian continent. To do so, we quantified bio ersity values and threats in each bioregion by gathering open‐access data on species, landscapes, and land use. Bioregions were then ranked using a set of customizable scenarios, including ecologically meaningful combinations of measures of irreplaceability and vulnerability. To identify bio erse areas under threat but potentially overlooked, we compared our results with the location of already established bio ersity hotspots (i.e., areas identified as important for bio ersity and under threat). We found that bioregions with the highest bio ersity values are predominantly located in the southwest, east, and north of the continent. Similarly, threats, particularly land clearance, are concentrated along the east coast and in the southwest. When ranking bioregions using scenarios including both threats and bio ersity values, the majority (75%) of the highest‐ranking bioregions were already included in bio ersity hotspots. For five of these bioregions, the proportion of protected land to date still falls below the 17% recommended by the Convention on Biological Diversity and thus they likely require prompt prioritization and intervention. The method proposed can support ongoing monitoring and prioritization of land units for conservation. Its simplicity and flexibility mean it can be easily adopted for different areas and adjusted to local priorities.
Publisher: Ornithological Society of Japan
Date: 02-02-2022
DOI: 10.2326/OSJ.21.3
Publisher: Elsevier BV
Date: 06-2023
Publisher: Cold Spring Harbor Laboratory
Date: 19-01-2021
DOI: 10.1101/2021.01.17.427044
Abstract: Vehicle collisions with wildlife can injure or kill animals, threaten human safety, and threaten the viability of rare species. This has led to a focus in road-ecology research on identifying the key predictors of ‘road-kill’ risk, with the goal of guiding management to mitigate its impact. However, because of the complex and context-dependent nature of the causes of risk exposure, modelling road-kill data in ways that yield consistent recommendations has proven challenging. Here we used a novel multi-model machine-learning approach to identify the spatio-temporal predictors, such as traffic volume, road shape, surrounding vegetation and distance to human settlements, associated with road-kill risk. We collected data on the location, identity and size of each road mortality across four seasons along eight roads in southern Tasmania – a ‘road-kill hotspot’ of management concern. We focused on three large-bodied and frequently impacted crepuscular Australian marsupial herbivore species, the rufous-bellied pademelon ( Thylogale billardierii ), Bennett’s wallaby ( Macropus rufogriseus ) and the bare-nosed wombat ( Vombatus ursinus ). We fit the point-location data using ‘lasso-regularization’ of a logistic generalized linear model (LL-GLM) and out-of-bag optimization of a decision-tree-based ‘random forests’ (RF) algorithm. The RF model, with high-level feature interactions, yielded superior results to the linear additive model, with a RF classification accuracy of 84.8% for the 871 road-kill observations and a true skill statistic of 0.708, compared to 61.2% and 0.205 for the LL-GLM. Forested areas with no roadside barrier fence along curved sections of road posed the highest risk to animals. Seasonally, the frequency of wildlife-vehicle collisions increased notably for females during oestrus, when they were more dispersive and so had a higher encounter rate with roads. These findings illustrate the value of using data-driven approaches to predictive modelling, as well as offering a guide to practical management interventions that can mitigate road-related hazards.
Publisher: Wiley
Date: 03-06-2016
DOI: 10.1111/REC.12387
Publisher: CSIRO Publishing
Date: 25-03-2022
DOI: 10.1071/WR21018
Abstract: Context Vehicle collisions with wildlife can injure or kill animals, threaten human safety, and threaten the viability of rare species. This has led to a focus in road-ecology research on identifying the key predictors of ‘road-kill’ risk, with the goal of guiding management to mitigate its impact. However, because of the complex and context-dependent nature of the causes of risk exposure, modelling road-kill data in ways that yield consistent recommendations has proven challenging. Aim Here we used a multi-model machine-learning approach to identify the spatio-temporal predictors, such as traffic volume, road shape, surrounding vegetation and distance to human settlements, associated with road-kill risk. Methods We collected data on the location, identity and wildlife body size of each road mortality across four seasons along eight roads in southern Tasmania, a ‘road-kill hotspot’ of management concern. We focused on three large-bodied and frequently affected crepuscular Australian marsupial herbivore species, the rufous-bellied pademelon (Thylogale billardierii), Bennett’s wallaby (Macropus rufogriseus) and the bare-nosed wombat (Vombatus ursinus). We fit the point-location data using ‘lasso-regularisation’ of a logistic generalised linear model (LL-GLM) and out-of-bag optimisation of a decision-tree-based ‘random forests’ (RF) algorithm for optimised predictions. Results The RF model, with high-level feature interactions, yielded superior out-of-s le prediction results to the linear additive model, with a RF classification accuracy of 84.8% for the 871 road-kill observations and a true skill statistic of 0.708, compared with 61.2% and 0.205 for the LL-GLM. The lasso rejected road visibility and human density, ranking roadside vegetation type and presence of barrier fencing as the most influential predictors of road-kill locality. Conclusions Forested areas with no roadside barrier fence along curved sections of road posed the highest risk to animals. Seasonally, the frequency of wildlife–vehicle collisions increased notably for females during oestrus, when they were more dispersive and so had a higher encounter rate with roads. Implications These findings illustrate the value of using a combination of attributive and predictive modelling using machine learning to rank and interpret a complexity of possible predictors of road-kill risk, as well as offering a guide to practical management interventions that can mitigate road-related hazards.
Publisher: CSIRO Publishing
Date: 03-12-2022
DOI: 10.1071/WR21056
Abstract: Abstract Context Reliable, cost-effective monitoring methods are essential for managing wildlife populations. Scat-and-sign surveys (i.e. monitoring defecation, animal scratching, footprints, food remains) are a rapid, low-cost, non-invasive monitoring approach, but unquantified biases and uncertainties associated with these methods have caused researchers to doubt their reliability. Aims We sought to quantify how richness, occupancy and activity estimates derived from a long-term camera-trap study differed from those of scat surveys in the same locations, to determine scat-survey reliability and model bias corrections. Methods We used transect-based scat surveys at 110 sites in the temperate forests of southern Tasmania (Australia), to estimate occupancy, activity and community richness for common, ground-dwelling vertebrates. These results were compared with estimates derived from a long-term passive camera-trap study at the same sites. In addition, time-lapse imagery taken with the camera traps was used to monitor the persistence of rufous-belled pademelon (Thylogale billardierii) and Tasmanian devil (Sarcophilus harrisii) scats in relation to environmental correlates. Key results Scat persistence differed between these two species. The half-life of S. harrisii scats was 113 days, compared with 63 days for T. billardierii. Generalised linear modelling showed that scat surveys were most efficacious at sites with little disturbance and homogenous substrates. Overall, scat surveys consistently underestimated site occupancy and richness relative to the camera traps (μ = 2.7:1), but this bias was inconsistent, with the ratio exceeding 15 for the arboreal brushtail possum (Trichosurus vulpecula). Scats were most reliably detected for large, trail-using mammals such as S. harrisii, T. billardierii, and common wombat (Vombatus ursinus). Scat surveys were less useful for the surveillance of low-density and arboreal species. Scats were uncommon for the two bird species examined, but alternative superb lyrebird (Menura novaehollandiae) signs were detected reliably. Conclusions Scat surveys reliably detected large, trail-using mammals. However, estimates of activity were poorly correlated between camera traps and scat surveys. Implications When used appropriately, scat surveys can provide an effective and cheap ‘snapshot’ index for wildlife monitoring, especially if the species-specific biases have been calibrated for the vertebrate community and environment under monitoring.
Publisher: Wildlife Disease Association
Date: 25-07-2022
Publisher: Wiley
Date: 23-05-2023
Abstract: Understanding the spatial dynamics and drivers of wildlife pathogens is constrained by s ling logistics, with implications for advancing the field of landscape epidemiology and targeted allocation of management resources. However, visually apparent wildlife diseases, when combined with remote‐surveillance and distribution modelling technologies, present an opportunity to overcome this landscape‐scale problem. Here, we investigated dynamics and drivers of landscape‐scale wildlife disease, using clinical signs of sarcoptic mange (caused by Sarcoptes scabiei ) in its bare‐nosed wombat (BNW Vombatus ursinus ) host. We used 53,089 camera‐trap observations from over 3261 locations across the 68,401 km 2 area of Tasmania, Australia, combined with landscape data and ensemble species distribution modelling (SDM). We investigated: (1) landscape variables predicted to drive habitat suitability of the host (2) host and landscape variables associated with clinical signs of disease in the host and (3) predicted locations and environmental conditions at greatest risk of disease occurrence, including some Bass Strait islands where BNW translocations are proposed. We showed that the Tasmanian landscape, and ecosystems therein, are nearly ubiquitously suited to BNWs. Only high mean annual precipitation reduced habitat suitability for the host. In contrast, clinical signs of sarcoptic mange disease in BNWs were widespread, but heterogeneously distributed across the landscape. Mange (which is environmentally transmitted in BNWs) was most likely to be observed in areas of increased host habitat suitability, lower annual precipitation, near sources of freshwater and where topographic roughness was minimal (e.g. human modified landscapes, such as farmland and intensive land‐use areas, shrub and grass lands). Thus, a confluence of host, environmental and anthropogenic variables appear to influence the risk of environmental transmission of S. scabiei . We identified that the Bass Strait Islands are highly suitable for BNWs and predicted a mix of high and low suitability for the pathogen. This study is the largest spatial assessment of sarcoptic mange in any host species, and advances understanding of the landscape epidemiology of environmentally transmitted S. scabiei . This research illustrates how host‐pathogen co‐suitability can be useful for allocating management resources in the landscape.
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.ENVINT.2019.105187
Abstract: Cities are home to over half the global population that proportion is expected to rise to 70% by mid-century. The urban environment differs greatly from that in which humans evolved, with potentially important consequences for health. Rates for allergic, inflammatory and auto-immune diseases appear to rise with urbanization and be higher in the more urbanized nations of the world which has led some to suggest that cities promote the occurrence of these diseases. However, there are no syntheses outlining what urban-associated diseases are and what characteristics of cities promote their occurrence. To synthesize the current understanding of "urban-associated diseases", and discover the common, potentially modifiable features of cities that may be driving these associations. We focus on any diseases that have been associated with cities or are particularly prominent in today's urban societies. We draw on expertise across erse health fields to examine the evidence for urban connections and drivers. We found evidence for urban associations across allergic, auto-immune, inflammatory, lifestyle and infectious disease categories. Some conditions (e.g. obesity and diabetes) have complex relationships with cities that have been insufficiently explored. Other conditions (e.g. allergies and asthma) have more evidence demonstrating their relationship with cities and the mechanisms driving that association. Unsurprisingly, air pollution was the characteristic of cities most frequently associated with disease. Other identified urban risk factors are not as widely known: altered microbial exposure and a disconnect from environmental microbiomes, vitamin D deficiency, noise and light pollution, and a transient, over-crowded, impoverished population. However, many complexities and caveats to these relationships beg clarification we highlight the current knowledge gaps and outline ways to fill those gaps. Identifying urban-associated diseases and their drivers will allow us to prepare for the urban-disease burden of the future and create healthy cities that mitigate that disease burden.
Publisher: The Royal Society
Date: 06-2023
DOI: 10.1098/RSOS.230386
Abstract: Identifying environmental characteristics that limit species' distributions is important for contemporary conservation and inferring responses to future environmental change. The Tasmanian native hen is an island endemic flightless rail and a survivor of a prehistoric extirpation event. Little is known about the regional-scale environmental characteristics influencing the distribution of native hens, or how their future distribution might be impacted by environmental shifts (e.g. climate change). Using a combination of local fieldwork and species distribution modelling, we assess environmental factors shaping the contemporary distribution of the native hen, and project future distribution changes under predicted climate change. We find 37% of Tasmania is currently suitable for the native hens, owing to low summer precipitation, low elevation, human-modified vegetation and urban areas. Moreover, in unsuitable regions, urban areas can create ‘oases’ of habitat, able to support populations with high breeding activity by providing resources and buffering against environmental constraints. Under climate change predictions, native hens were predicted to lose only 5% of their occupied range by 2055. We conclude that the species is resilient to climate change and benefits overall from anthropogenic landscape modifications. As such, this constitutes a rare ex le of a flightless rail to have adapted to human activity.
Publisher: Pensoft Publishers
Date: 29-06-2017
Publisher: Elsevier BV
Date: 08-2020
Publisher: Wiley
Date: 29-06-2023
DOI: 10.1002/ECY.4124
Publisher: Wiley
Date: 31-08-2018
DOI: 10.1002/ECE3.4455
Publisher: Wiley
Date: 23-12-2022
DOI: 10.1002/ECY.3597
Abstract: The spatial analysis of linear features (lines and curves) is a challenging and rarely attempted problem in ecology. Existing methods are typically expressed in abstract mathematical formalism, making it difficult to assess their relevance and transferability into an ecological setting. We introduce a set of concrete and accessible methods to analyze the spatial patterning of line‐segment data. The methods include Monte Carlo techniques based on a new generalization of Ripley's ‐function and a class of line‐segment processes that can be used to specify parametric models: parameters are estimated using maximum likelihood and models compared using information‐theoretic principles. We apply the new methods to fallen tree (dead log) data collected from two 1‐ha Australian tall eucalypt forest plots. Our results show that the spatial pattern of the fallen logs is best explained by plot‐level spatial heterogeneity in combination with a slope‐dependent nonuniform distribution of fallen‐log orientations. These methods are of a general nature and are applicable to any line‐segment data. In the context of forest ecology, the integration of fallen logs as linear structural features in a landscape with the point locations of living trees, and a quantification of their interactions, can yield new insights into the functional and structural role of tree fall in forest communities and their enduring post‐mortem ecological legacy as spatially distributed decomposing logs.
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/WR18128
Abstract: ContextTasmania has been called the roadkill capital of Australia. However, little is known about the population-level impact of vehicle mortality on native mammals in the island state. AimsThe aims were to investigate the predictability of roadkill on a given route, based on models of species distribution and live animal abundance for three marsupial species in Tasmania – the Tasmanian pademelon (Thylogale billardierii), Bennett’s wallaby (Macropus rufogriseus) and the bare-nosed wombat (Vombatus ursinus) – and to assess the possibility of predicting the magnitude of state-wide road mortality based on live animal abundance. MethodsRoad mortality of the three species was measured on eight 15-km road segments in south-eastern Tasmania, during 16 weeks over the period 2016–17. Climate suitability was predicted using state-wide geographical location records, using species distribution models, and counts of these species from 190 spotlight survey roads. Key resultsThe Tasmanian pademelons were the most frequently killed animal encountered over the study period. Live abundance, predicted by fitting models to spotlight counts, did not correlate with this fatality rate for any species. However, the climate suitability index generated by the species distribution models was strongly predictive for wombat roadkill, and moderately so for pademelons. ConclusionsAlthough distributional and wildlife abundance records are commonly available and well described by models based on climate, vegetation and land-use predictors, this approach to climate suitability modelling has limited predictability for roadkill counts on specific routes. ImplicationsRoad-specific factors, such as characteristics of the road infrastructure, nearby habitats and behavioural traits, seem to be required to explain roadkill frequency. Determining their relative importance will require spatial analysis of roadkill locations.
Publisher: Wiley
Date: 09-03-2021
DOI: 10.1111/ELE.13705
Abstract: Animals alter their habitat use in response to the energetic demands of movement (‘energy landscapes’) and the risk of predation (‘the landscape of fear’). Recent research suggests that animals also select habitats and move in ways that minimise their chance of temporarily losing control of movement and thereby suffering slips, falls, collisions or other accidents, particularly when the consequences are likely to be severe (resulting in injury or death). We propose that animals respond to the costs of an ‘accident landscape’ in conjunction with predation risk and energetic costs when deciding when, where, and how to move in their daily lives. We develop a novel theoretical framework describing how features of physical landscapes interact with animal size, morphology, and behaviour to affect the risk and severity of accidents, and predict how accident risk might interact with predation risk and energetic costs to dictate movement decisions across the physical landscape. Future research should focus on testing the hypotheses presented here for different real‐world systems to gain insight into the relative importance of theorised effects in the field.
Publisher: Springer Science and Business Media LLC
Date: 04-12-2018
Publisher: Wiley
Date: 15-07-2019
DOI: 10.1002/ECY.2787
Abstract: The pattern of sightings of a species that is rare, and then no longer observed, can be used to estimate its extinction date. However, other than physical captures or specimens, the veracity of any sighting is ambiguous, and should be treated probabilistically when used to infer extinction dates. We present a simple yet powerful computational approach for incorporating observational reliability into extinction date estimators (EDE). Our method (1) combines repeated within-year sightings probabilistically, (2) s les observations using reliability as an inclusion probability, (3) infers a probability distribution and summary statistics of extinction dates with any EDE, and (4) computes the frequency distribution of the extinction date. We applied this method to eight exemplar sighting records covering a range of lengths, sighting rates and uncertainties, using a variety of statistical EDEs, and compared these results with a threshold approach for selecting sightings. We also demonstrated a robust coverage of "true" extinction dates based on selected real-world ex les of rediscovered species and confirmed extinctions, and simulated sighting records. Our approach represents a powerful generalization of past work because it is not predicated on any specific method for inferring extinction dates, and yet is simple to implement (with R script provided).
No related grants have been discovered for Jessie Buettel.