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Showing papers in "Animal Conservation in 2019"


Journal ArticleDOI
TL;DR: It is shown here using a detailed pedigree and genomic data that genetic rescue in the gray wolf Canis lupus population on Isle Royale had only a temporary positive effect reducing inbreeding depression and then the genetic changes from the immigration event resulted in a population decline and now imminent extinction of the population.
Abstract: Genetic factors have long been a concern in the extinction and viability of species with the short-term effects focusing on inbreeding depression. Genetic rescue has been suggested as a means to overcome the detrimental effects of inbreeding depression. However, it has been difficult to document the genetic dynamics over time of genetic rescue, inbreeding depression and other genetic relationships in endangered species. We show here using a detailed pedigree and genomic data that genetic rescue in the gray wolf Canis lupus population on Isle Royale had only a temporary positive effect reducing inbreeding depression and then the genetic changes from the immigration event resulted in a population decline and now imminent extinction of the population. Examining the genetic details of this situation shows how genetic dynamics after the initial positive effects of genetic rescue have passed can return a small population to a path toward extinction. Thus, the successful conservation of critically small populations would likely depend on alleviating the cause of having become critically small, such as habitat restoration, or periodic re-application of genetic rescue in a manner that does not result in negative genetic dynamics.

48 citations


Journal ArticleDOI
TL;DR: In this paper, the authors used gridded hourly air temperature forecasts from the Australian Community Climate and Earth-System Simulator (ACCESS-R) Numerical Weather Prediction (NWP) model to predict flying-fox heat-related mortality based on an empirically determined threshold of 42.0°C.
Abstract: Extreme heat events pose increasing challenges to biodiversity conservation worldwide, yet our ability to predict the time, place and magnitude of their impacts on wildlife is limited. Extreme heat events in Australia are known to kill thousands of flying-foxes (Pteropus spp.), and such die-offs are expected to become more frequent and widespread in the future under anthropogenic climate change. There is a growing need for predicting when and where such heat-related die-offs would occur, to facilitate short-term wildlife management and conservation actions. In this study, we used gridded hourly air temperature forecasts [Australian Community Climate and Earth-System Simulator (ACCESS-R) Numerical Weather Prediction (NWP) model] from the Australian Bureau of Meteorology to predict flying-fox heat-related mortality based on an empirically determined threshold of 42.0°C. We tested the accuracy and precision of this model using a twofold evaluation of the ACCESS-R NWP forecast air temperature during a recorded extreme heat event with in situ air temperature measurements and interpolated weather station data. While our results showed a slight discrepancy between the modelled and measured air temperatures, there was no significant difference in the forecast's accuracy to predict die-offs during an extreme heat event and the overall summer period. We evaluated the accuracy of mortality predictions based on different air temperature thresholds (38.0, 40.0, 42.0 and 44.0°C). Our results revealed a significant probability of flying-fox mortality occurrence when forecast air temperature was ≥42.0°C, while the 24- and 48-h forecasts accurately predicted 77 and 73% of the die-offs, respectively. Thus, the use of 42.0°C forecast air temperature from the ACCESS-R NWP model can predict flying-fox mortality reliably at the landscape scale. In principle, the forecaster can be used for any species with known thermal tolerance data and is therefore a promising new tool for prioritizing adaptation actions that aim to conserve biodiversity in the face of climate change.

48 citations



Journal ArticleDOI
TL;DR: In this paper, the authors used step-selection functions (SSFs) to build functional connectivity models for African elephants Loxodonta africana in a seasonal environment to illustrate the temporal variability of functional landscape connectivity.
Abstract: Landscape connectivity is an important component of systematic conservation planning. Step-selection functions (SSFs) is a highly promising method for connectivity modeling. However, differences in movement behavior across individuals and seasons are usually not considered in current SSF-based analyses, potentially leading to imprecise connectivity models. Here, our objective was to use SSFs to build functional connectivity models for African elephants Loxodonta africana in a seasonal environment to illustrate the temporal variability of functional landscape connectivity. We provide a methodological framework for integrating detected interindividual variability into resistance surface modeling, for assessing how landscape connectivity changes across seasons, and for evaluating how seasonal connectivity differences affect predictions of movement corridors. Using radio-tracking data from elephants in the Borderland area between Kenya and Tanzania, we applied SSFs to create seasonal landscape resistance surfaces. Based on seasonal models, we predicted movement corridors connecting major protected areas (PAs) using circuit theory and least-cost path analysis. Our findings demonstrate that individual variability and seasonality lead to substantial changes in landscape connectivity and predicted movement corridors. Specifically, we show that the models disregarding seasonal resource fluctuations underestimate connectivity for the wet and transitional seasons, and overestimate connectivity for the dry season. Based on our seasonal models, we predicted a connectivity network between large PAs and highlight seasonal and consistent patterns that are most important for effective management planning. Our findings reveal that elephant movements in the borderland between Kenya and Tanzania are essential for maintaining connectivity in the dry season, and that existing corridors do not protect these movements in full extent.

39 citations


Journal ArticleDOI
TL;DR: In this paper, a willingness to donate survey of potential online donors from Finland was conducted to identify which motivations and donor characteristics influence their preferences for a range of different flagship species and ecosystems.
Abstract: Environmental non‐governmental organizations (ENGOs) largely select flagship species for conservation marketing based on their aesthetic appeal. However, little is known about the fundraising effectiveness of this approach or how it compares to ecosystem conservation campaigns that use habitat types as flagships. By performing a willingness to donate (WTD) survey of potential online donors from Finland, we identified which motivations and donor characteristics influence their preferences for a range of different flagship species and ecosystems. Using the contingent valuation method and the payment card approach, we found the combined funding for eight mammal flagship species was 29% higher funding than for eight bird flagship species. Furthermore, the aesthetically more appealing species, as well as the species and ecosystems that are native to Finland, attracted the most funding. We then used ordinal logistic regression to identify the factors influencing a donor's WTD, finding that knowledge of biodiversity conservation and familiarity with the flagship was associated with an increased WTD to birds and ecosystems, and people with higher education levels had an increased WTD to ecosystems. Surprisingly, species aesthetic appeal was not related to an increased WTD, although “need of conservation” was, suggesting that highlighting the plight of these less appealing threatened species or ecosystems could raise money. Our results suggest that the factors driving donating to mammals, birds or ecosystems differ, and so underline the importance of considering the diverse motivations behind donation behaviour in fundraising campaigns. They also provide new evidence of the motivations of online donors, an under‐studied group who are likely to become an increasingly important source of conservation funding.

35 citations



Journal ArticleDOI
TL;DR: The results indicate that there are immunogenetic differences among captive southern corroboree frogs; such differences could be manipulated to increase disease resistance and mitigate the significant threat of chytridiomycosis.
Abstract: Hundreds of amphibian species have declined worldwide after the emergence of the amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd). Despite captive breeding efforts, it is unlikely that wild populations for many species will be reestablished unless Bd resistance increases. We performed a Bd‐challenge study in the functionally extinct southern corroboree frog Pseudophryne corroboree to investigate differences in Bd susceptibility among individuals and populations, identify genetic [major histocompatibility complex (MHC) class I] and genome‐wide variants associated with Bd resistance, and measure genetic diversity and population genetic structure. We found three MHC variants and one MHC supertype associated with Bd infection load and survival along with a suggestively associated single nucleotide polymorphism. We also showed that genome‐wide heterozygosity is associated with increased survival. Additionally, we found evidence of significant population structure among the four P. corroboree populations studied and high MHC genetic diversity. Our results indicate that there are immunogenetic differences among captive southern corroboree frogs; such differences could be manipulated to increase disease resistance and mitigate the significant threat of chytridiomycosis. These results demonstrate a potential long‐term solution to chytridiomycosis that could include breeding more resistant individuals and returning them to the wild.

27 citations


Journal ArticleDOI
TL;DR: In this paper, the 45 candidate models used to investigate factors affecting wildlife collisions were compared and the top model is indicated in bold, where delta AICc ≤ 2 and the bottom model is shown in red.
Abstract: Table S1. The 45 candidate models used to investigate factors affecting wildlife collisions. The top model is indicated in bold, where delta AICc ≤ 2.

25 citations



Journal ArticleDOI
TL;DR: In this paper, the authors evaluated the role of several environmental factors describing habitat quality for wolves Canis lupus in the humanised Iberian Peninsula, which currently holds an important wolf population at European level.
Abstract: Despite severe population declines and an overall range contraction, some populations of large carnivores have managed to survive in human-modified landscapes. From a conservation perspective, it is important to identify the factors allowing for this coexistence, including the relevant habitat characteristics associated with the presence of large carnivores. We evaluated the role of several environmental factors describing habitat quality for wolves Canis lupus in the humanised Iberian Peninsula, which currently holds an important wolf population at European level. We used maximum entropy and generalized linear model approaches in a nestedscale design to identify the environmental factors that are related to wolf presence at three spatial scales and resolutions: (1) distribution range: wolf presence on a 10 9 10 km grid resolution, (2) wolf habitat use: wolf occurrence on a 2 9 2 km grid and (3) dens/rendezvous sites: breeding locations on a 1 9 1 km grid. Refuge availability, as defined by topography, seemed to be the key factor determining wolf presence at the multiple scales analysed. As a result, wolf populations may coexist with humans in modified landscapes when the topography is complex. We found that a significant amount of favourable habitat is not currently occupied, suggesting that the availability of suitable habitat is not the limiting factor for wolves in the Iberian Peninsula. Habitat suitability outside the current range indicates that other factors, such as direct persecution and other sources of anthropogenic mortality, may be hampering its expansion. We suggest that priorities for conservation should follow two general lines: (1) protect good quality habitat within the current range; and (2) allow dispersal to unoccupied areas of good quality habitat by reducing human-induced mortality rates. Finally, we still need to improve our understanding of how wolves coexist with humans in modified landscapes at fine spatiotemporal scales, including its relationship with infrastructures, land uses and direct human presence.

23 citations



Journal ArticleDOI
TL;DR: In this paper, the authors report rapid declines and extinctions of adder populations monitored during 12 years in Belgium where none of the above causes was involved, showing that wild boars represent a major risk for snakes, pushing populations to extinction.
Abstract: Climatic changes, habitat loss and invasive species are important threats for many animal populations. Here, we report rapid declines and extinctions of adder populations monitored during 12 years in Belgium where none of the above causes was involved. This study provides the first large-scale data showing that wild boars represent a major risk for snakes, pushing populations to extinction. Drastic population declines were observed in the sites impacted by wild boars (N = 14), while in other sites spared by wild boars populations remained stable (N = 9). Wild boars are highly fertile and their main predators have been extirpated from Western Europe; yet, recreational hunting kept populations in check during decades. Hunting pressure is currently insufficient to control the rapid expansion of wild boars, demographic outbreaks are increasingly frequent. Wild boars are omnivorous; they can destroy snakes directly and indirectly through the depletion of snake’s preys and via the destruction of key microhabitats. Snakes exhibit limited dispersal capacities; they cannot escape local perturbations and thus are highly vulnerable. Because wild boars have a very eclectic diet, are prolific breeders and are able to devastate a range of habitats their negative impact under relaxed hunting pressure applies to a huge variety of organisms, including reptiles. Policies to limit wild boar populations are urgently needed. Recommendations to target reproductive females and piglets should be generalized and applied.


Journal ArticleDOI
TL;DR: The results indicate that parasitism by nest flies decreases survival and fledging success of nestling Ridgway's hawks and is a possible factor in the decline of the species.
Abstract: Parasitic nest flies Philornis spp. are a driving force threatening the extinction of bird species endemic to Neotropical islands such as the Galapagos, where introduced Philornis downsi negatively impacts reproductive success of naive avian hosts. Elsewhere in the Neotropics, such as in the Caribbean region where Philornis nest flies are native, effects of Philornis on host productivity are poorly known. We manipulated parasitism by the native Hispaniolan nest fly Philornis pici on a critically endangered endemic host, Ridgway's hawk Buteo ridgwayi, to study the impact of nest fly myiasis on hawk breeding success with the goal of providing a management option for endangered species until broad‐scale solutions can be found. Our treatment protocol was enough to reduce P. pici abundance by 89% and increase probability of fledging by 179% for treated nestlings. Our results indicate that parasitism by nest flies decreases survival and fledging success of nestling Ridgway's hawks and is a possible factor in the decline of the species. To the best of our knowledge, this work represents the first quantitative evidence of nest fly impact on survival or productivity in a non‐passerine host.


Journal ArticleDOI
TL;DR: The bottlenecks associated with the survival of juvenile anguillid eels migrating to warmer waters are known to be severe and fast-moving and therefore important for their survival.
Abstract: Conservation programmes for endangered, long-lived and migratory species often have to target multiple life stages. The bottlenecks associated with the survival of juvenile anguillid eels migrating ...


Journal ArticleDOI
TL;DR: Examination of post‐capture and post‐commercial transportation consequences in pregnant females obtained as bycatch from artisanal fisheries in Southern Brazil showed high abortion rates and reduced maternal survival after abortion, with all abortions occurring within 28 h of monitoring in laboratory.
Abstract: The fate of bycatch species released back into the water is crucial to estimate population status and consequent decisions to implement adequate management measurements for elasmobranchs. The shortnose guitarfish, Zapteryx brevirostris, is an endemic species of the Southwest Atlantic. It is currently listed as ‘Vulnerable’ both in the International Union for Conservation of Nature and Brazilian red lists. Although this species displays high tolerance to capture and transportation by fishers from the capture site to the fish market, a significant reduction in survival rates is observed during the reproductive period. Thus, the aim of the present study was to examine post‐capture and post‐commercial transportation consequences in pregnant females obtained as bycatch from artisanal fisheries in Southern Brazil. Results showed high abortion rates and reduced maternal survival after abortion, with all abortions occurring within 28 h of monitoring in laboratory. Stress plasma markers were also evaluated, to determine the physiological consequences of capture‐induced parturition to pregnant females. Results showed alteration in all markers measured (plasma urea, pH, lactate, phosphorus, and potassium) with values for dead pregnant females being different from non‐pregnant females and those which survived capture and subsequent abortions. The mortality caused by fisheries bycatch may prove difficult to manage, with immediate release and specific handling protocols for pregnant females implemented through environmental education environmental education and fishermen training programs, potential options to maintain adequate maternal survival and recruitment for this species.

Journal ArticleDOI
TL;DR: This project was funded by the Australian National University Research and School of Biology, and by grants to AE from Birdlife Australia as mentioned in this paper and the Natural Science and Engineering Council of Canada.
Abstract: This project was funded by the Australian National University Research School of Biology, and by grants to AE from Birdlife Australia (Emu-Austral Ornithology Award, Professor Allen Keast Student Research Award, Stuart Leslie Bird Research), the Paddy Pallin Foundation (Terrestrial Conservation Grant), the Australian Academy of Science (Margaret Middleton Fund for Endangered Australian Vertebrates), the Ecological Society of Australia (Jill Landsberg Trust Fund Scholarship), Sigma Xi Scientific Research Society (Grants-in-aid of research), the Natural Science and Engineering Council of Canada (Postgraduate Scholarship-Doctoral) and the Holsworth Wildlife Research Fund. Research methods were approved by the ANU Animal Ethics Committee (AEEC 2012/34), and the Tasmania Department of Primary Industries, Parks, Water and the Environment (Scientific permits TFA13956 and TFA14295).

Journal ArticleDOI
TL;DR: It is estimated that headstarts at the authors' sites have approximately three times higher probability of surviving to 10 years of age, compared to wild‐hatched individuals at other sites, and the need to investigate whether post‐release mortality of captive‐reared animals could be mitigated by increased acclimation to wild conditions, for example through prerelease periods in outdoor pens is investigated.
Abstract: Wildlife diversity and abundance are declining globally and population reinforcement with captive‐reared animals is a common intervention used to prevent extinctions. Released captive‐reared individuals may undergo an acclimation period before their behavior and success is comparable to wild‐reared individuals because they lack experience with predators, complex habitats and variable environmental conditions. Quantifying post‐release acclimation effects on fitness and behavior is important for maximizing the success of reintroduction programs and for predicting the number of captive‐reared animals required for release. Endangered Blanding's turtles Emydoidea blandingii exhibit low recruitment and may benefit from population reinforcement with captive‐reared, ‘headstarted’ individuals (headstarts). We used 6 years of data to compare survival, growth, habitat use and movement ecology between wild‐hatched juvenile turtles and headstarts reared from eggs rescued from injured females. We found strong evidence of an acclimation effect in headstarts, with lower movement, growth, and survival during the first one to two years post‐release. Following this acclimation period, headstarts had movement, growth and survival similar to wild‐hatched juveniles. Habitat use did not differ between headstarts and wild‐hatched juveniles. We hypothesize that the acclimation period occurred because headstarts were introduced directly into the wild (i.e. ‘hard release’) and that providing additional support before or after release may improve the success of headstarts. Headstarts had a monthly survival probability of 0.89 in the first year post‐release, and 0.98 after the first year post‐release. We estimated that headstarts at our sites have approximately three times higher probability of surviving to 10 years of age, compared to wild‐hatched individuals at other sites. Our results highlight that headstarts should be released into habitat individually rather than in clusters, and highlight the need to investigate whether post‐release mortality of captive‐reared animals could be mitigated by increased acclimation to wild conditions, for example through prerelease periods in outdoor pens.



Journal ArticleDOI
TL;DR: In this article, the authors highlight the relative lack of spatial data available in the Western Indian Ocean (WIO), and the prevalence of transboundary movements in species that have previously been studied in the region.
Abstract: Transboundary marine species have an increased risk of overexploitation as management regimes and enforcement can vary among states. The complex geopolitical layout of exclusive economic zones (EEZs) in the Western Indian Ocean (WIO) introduces the potential for migratory species to cross multiple boundaries, consequently a lack of scientific data could complicate regional management. In the current study, we highlight both the relative lack of spatial data available in the WIO, and the prevalence of transboundary movements in species that have previously been studied in the region. Five tiger sharks Galeocerdo cuvier were tracked with near real‐time positioning (SPOT) satellite tags to determine individual shark movements relative to EEZs within the WIO. Concurrently, a literature search was performed to identify all satellite telemetry studies conducted to date in the WIO for marine megafaunal species, and the results compared to global satellite telemetry effort. Finally, the satellite tracks of all marine species monitored in the WIO were extracted and digitized to examine the scale of transboundary movements that occur in the region. Tiger sharks exhibited both coastal and oceanic movements, with one individual crossing a total of eight EEZs. Satellite telemetry effort in the WIO has not matched the global increase, with only 4.7% of global studies occurring in the region. Species in the WIO remained within the EEZ in which they were tagged in only three studies, while all other species demonstrated some level of transboundary movement. This study demonstrates the lack of spatial data available for informed regional management in an area where transboundary movements by marine megafauna are highly prevalent. Without more dedicated funding and research, the rich biodiversity of the WIO is at risk of overexploitation from the diverse threats present within the various political regions.

Journal ArticleDOI
TL;DR: In this paper, the authors studied changes to the vigilance/group-size effect in Nubian ibex Capra nubiana in response to increased nonthreatening anthropogenic disturbance in six sites, subject to different levels of ecotourism.
Abstract: Increased fragmentation and easier access to natural areas (e.g. ecotourism) is bringing man in closer contact to wild populations. Such encounters, even when they don’t pose a direct threat to wildlife, may induce behavioral changes in animals that in the long run may have negative fitness consequences. We studied changes to the vigilance/group-size effect in Nubian ibex Capra nubiana in response to increased non-threatening anthropogenic disturbance in six sites, subject to different levels of ecotourism. In each site we regressed the average time ibex individuals devoted to vigilance on the size of the group they were with. We then compared the slopes and intercepts of the vigilance/group-size function between the six sites. We complimented these data with a study of how flight initiation distance (FID) changed between the six sites, as an indicator of the level of tolerance that ibex exhibit to increased anthropogenic presence. We found that as anthropogenic presence increased the vigilance/group-size function waned (i.e. the group-size effect was weaker). These findings were associated with reduced FID reflecting increased levels of tolerance, likely as a result of habituation in sites subject to high levels of ecotourism. The loss of the vigilance response as a function of group size may decrease the behavioral diversity in the ibex population. Wildlife habituation to increased non-threatening human activity alters key behavioral attributes that may ultimately impact social structure and other fitness-related characteristics.

Journal ArticleDOI
TL;DR: In this paper, the authors studied the landscape features affecting tiger gene flow in the western Ghats and examined how and why limiting landscape features differ between Central India and the Western Ghats, and assessed whether these landscape features have been altered by land use changes in the last five decades.
Abstract: Integrated landscape management of key population areas along with the corridors linking them is important for tiger conservation in the Indian subcontinent. Relationships between gene flow and landscape patterns, however, cannot be generalized given that different limiting factors influence movement in different spatial contexts. Here, we study the landscape features affecting tiger gene flow in the Western Ghats, and examine how and why limiting landscape features differ between Central India and the Western Ghats. We also assess whether these landscape features have been altered by land use changes in the last five decades. Our study area covers 30 000 km2 from Bhadra Tiger Reserve to the Nilgiri Biosphere Reserve in India. We used genetic data of 115 tigers and landscape resistance model optimization to create a resistance surface to gene flow in the Western Ghats. Tiger gene flow, both in Central India and the Western Ghats, is primarily related to topographic roughness and secondarily to diffuse disturbance, however these relations are inverted in the two landscapes - in Central India, gene flow correlates with rough terrain, whereas in the Western Ghats, it correlates with smooth, forested terrain with minimal human disturbance. Topographic complexity is an important factor affecting tiger dispersal, but tiger’s response to topography seems to be dependent upon interactions with human-related disturbance. Tigers in Central India favor rough terrain for dispersal primarily because it is the only part of the landscape without heavy human footprint and the last refuge for natural vegetation, whereas in the Western Ghats, forest cover is more extensive in flatter terrain and human footprint is generally lower.


Journal ArticleDOI
TL;DR: The results suggest that some generalist frog species may have an affinity for habitats within agricultural paddocks, particularly when key habitat features like plantings are present, and overall frog richness was low and did not differ between remnant patches, edges and farmland which may be an indication of habitat degradation within terrestrial habitats across the landscape.
Abstract: Mitigating the negative impacts of agriculture on amphibians requires knowledge of how different land uses affect species distribution and community composition. In the case of frogs, there is currently insufficient information on their use of terrestrial habitats in cropping landscapes to inform conservation planning. We examined how four different farmland types (linear plantings, cereal crops, grazing paddocks and woody mulch) and crop harvesting influenced amphibian abundance, richness, body condition and movement. We found the abundance of frogs was significantly higher in linear plantings compared to grazing paddocks and adjacent patches of remnant woodland vegetation. However, species richness and abundance of three individual species did not vary significantly between farmland types. For the most common frog Uperoleia laevigata, body condition was higher at the edges of the woody debris treatment (coupled with higher abundance) and lower in farmland with debris and linear plantings. The body condition of Limnodynastes tasmaniensis and L. interioris was not influenced by farmland type. Frog abundance and condition was largely unaffected by crop harvesting. However, frogs were less common after harvesting at the edges of farmland and within remnant patches. Movement patterns did not suggest mass movement out of crops after harvest, where almost half of all individuals recaptured remained within the farmland. These results suggest that some generalist frog species may have an affinity for habitats within agricultural paddocks, particularly when key habitat features like plantings are present. However, we found overall frog richness was low and did not differ between remnant patches, edges and farmland which may be an indication of habitat degradation within terrestrial habitats across the landscape. Although protection of remnant native vegetation is important, conservation strategies for the protection of amphibians will be ineffective if they do not consider the variety of land uses and the relationships of different species and their microhabitats within and outside of patches.

Journal ArticleDOI
TL;DR: In this paper, a model-averaging, information-theoretic approach identified tourist approach distance, viewing time and individual encounter exposure as the most significant predictors of rhinoceros disturbance level.
Abstract: Tourism may benefit conservation, but some wildlife viewing practices threaten the sustainability of both business and conservation initiatives. In north-west Namibia, conservation-oriented tourism provides tourists with an opportunity to encounter the critically-endangered black rhinoceros Diceros bicornis on foot. We used 123 tourist-rhinoceros encounters and employed a statistical modeling approach to: (1) identify the characteristics of human-rhinoceros encounters that caused rhinoceros disturbance and displacement; and (2) design rhinoceros-human encounter guidelines that improve sustainability. A model-averaging, information-theoretic approach identified tourist approach distance, viewing time and individual encounter exposure as the most significant predictors of rhinoceros disturbance level. A suite of rhinoceros viewing scenarios were modeled for acceptable disturbance risks, and adopted as a rhinoceros viewing policy. The policy reduced encounter displacements by 80% while maintaining a 95% positive feedback rating from guests. We demonstrate an evidence-based, policy-oriented management approach can help improve tourism's contribution towards the conservation of an endangered species.


Journal ArticleDOI
TL;DR: In this paper, the authors compared the presence/absence distribution across one landscape survey and three EIA surveys, and found that occupancy was not well predicted by koala habitat criteria widely used to inform sampling design.
Abstract: Vegetation clearing has been implicated as a major contributor to biodiversity loss. It therefore stands to reason that developers should face a regulatory requirement to assess potential impacts and to avoid, mitigate and compensate for loss of vegetation wherever proposed infrastructure developments impact on vegetation considered to be habitat for threatened species. Environmental Impact Assessments (EIA) rely on accurate information to describe the distributions of threatened species within the footprint of proposed infrastructure developments, which is critical to ensuring appropriate mitigation of potentially deleterious impacts on these populations. EIA survey guidelines seek to determine species’ presence accurately, while acknowledging the limits imposed by time and budget constraints. As such, the EIA guidelines may recommend: (1) stratifying the landscape based on previous knowledge of habitat variables relevant to a species; and (2) targeting survey effort to strata with high probability of occupancy. Here, we use koala Phascolarctos cinereus surveys as a case study to explore the extent to which application of EIA guidelines result in accurate occupancy estimates. We compared the presence/absence distribution across one landscape survey and three EIA surveys, and found that koala occupancy was not well predicted by koala habitat criteria widely used to inform sampling design. In the context of EIA, we provide an example of how targeting survey effort to strata with high probability of occupancy risks misrepresenting true occurrence patterns. A general issue with survey designs that rely on previous knowledge is that they self-reinforce erroneous assumptions. Our findings stand as a warning that EIA might neither quantify the impact of proposed infrastructure developments adequately, nor inform the ensuing mitigation measures. Threatened species’ protection in the face of infrastructure development will require new approaches to EIAs to ensure that providers are enabled to undertake comprehensive environmental surveys capable of detecting priority species.