Limited Conservation Resources Research Articles

Stakeholders' knowledge of threatened freshwater fishes and their involvement in fishery value chains in order to assist conservation in developing countries

IntroductionImproved conservation of exploited freshwater biodiversity is an increasing priority globally, but in developing countries there is often little insight of stakeholder attitudes within the value chains through which exploited species are passed, upon which to make informed management decisions.MethodsWe determined knowledge concerning threatened freshwater fishes in Bangladesh by key stakeholder groups (fishermen, faria agents, commission agents, retailers and consumers; n = 485 respondents) and their participation level in the threatened fish value chain. We also determined factors affecting local ecological knowledge and participation in the value chain.Results and discussionThe highest mean number of threatened fish species (4.8 ± 3.5% of species) was identified by the fishermen group, whereas consumers identified fewest (0.5 ± 1.1% of species). All respondent groups participated in the threatened fish value chain and their participation varied across respondent groups. 45.3% of the total number of threatened fish species appeared in the value chain. Participation level was highest for commission agents, involved in the trade of 21.5 ± 4.2% of threatened fish species, and lowest for consumers (7.4 ± 6.5% of threatened species). For fishermen, the principal component “experience-income-age” and the interaction between education and financial loan factors affected fishers' participation in the threatened fish value chain positively whereas, this was negatively affected by their knowledge level of threatened fishes. This study reveals the poor knowledge of stakeholder groups regarding threatened fishes, but establishes their active participation in the value chain of these species in Bangladesh. With limited resources for conservation of threatened species in many developing countries, it is very risky to implement commonly used in-situ conservation methods (e.g., habitat quality improvement) without fuller buy-in from the stakeholders.ConclusionsWe recommend specific protection laws for threatened fishes and awareness building campaigns for stakeholder groups to ensure minimum impact to threatened fish species. As overharvesting is a major cause of threatened fish species decline, such training programmes should be designed for fishers in developing regions. Education programmes on threats to ecosystems and biodiversity should be prioritized in schools and fishing communities. In addition, regular monitoring for protected species at harvesting sites and fishing markets should be ensured.

Conservation genetics of Sclerocactus in Colorado: the importance of accurate taxonomy to conservation

IntroductionRecent advances in genetic data collection utilizing next-generation DNA sequencing technologies have the potential to greatly aid the taxonomic assessment of species of conservation concern, particularly species that have been difficult to describe using morphology alone. Accurate taxonomic descriptions aided by genetic data are essential to directing limited conservation resources to species most in need. Sclerocactus glaucus is a plant endemic to Western Colorado that is currently listed as Threatened under the Endangered Species Act (ESA). However, in 2023, the U. S. Fish and Wildlife Service proposed de-listing S. glaucus from the ESA due to recovery of the species. Previous research had found substantial genetic structure between populations in the northern part of the S. glaucus range relative to the majority of the species distribution.MethodsIn this study we utilized double-digest Restriction-site Associated DNA sequencing (RAD-seq) in order to better understand the genetic structure of S. glaucus.ResultsOur results indicate that S. glaucus contains two distinct evolutionary lineages that warrant recognition at the level of species, with what was previously described as S. glaucus North being recognized as Sclerocactus dawsoniae.DiscussionThe newly described S. dawsoniae has a limited estimated number of individuals, low levels of nucleotide diversity, a very narrow geographic range, and an uneven geographic distribution with most plants being found in a single management area, all of which supports continued direct conservation of this species. In contrast, S. glaucus has a large estimated minimum population size, a broad geographic range that includes numerous protected areas, and adequate levels of genetic diversity. Without further conservation action, a delisting decision for S. glaucus will simultaneously remove all Endangered Species Act protections for S. dawsoniae. The current work demonstrates the importance of having robust genetic datasets when planning conservation activities for species of concern. Moving forward, we recommend that government stakeholders prioritize supporting genetic studies of endangered species prior to making any changes to listing decisions.

Strategic monitoring to minimize misclassification errors from conservation status assessments

Classifying species into risk categories is a ubiquitous process in conservation decision-making affecting regulatory procedures, conservation actions, and guiding resource allocation at global, national, and regional scales. However, monitoring programs often do not provide data required for accurate species classification decisions. Misclassification can lead to otherwise preventable species extinctions, undue regulatory burden, poor allocation of limited conservation resources, and can undermine species conservation legislation. We developed a framework that evaluates monitoring designs based on the ability to correctly inform a species classification decision, where minimizing the risk of misclassification is the central objective. We further evaluated monitoring designs by calculating the expected value of information and explored the relationship between statistical power to detect trends and misclassification. Our measure of misclassification risk, which can be tailored to the decision context, clarified the costs of over- and under-protection. High power to detect trends often corresponded to accurate species classification decisions. However, in several scenarios power to detect trends was low but the ability to correctly inform the classification decision was high. The value of information generally increased with monitoring intensity and quantified the tradeoffs between spatial and temporal replication. Our framework allows managers to assess monitoring program performance with direct implications for conservation decision-making. Our framework affords practitioners an opportunity to evaluate the effectiveness of monitoring programs a priori focusing on improving conservation decisions. We demonstrate that prioritizing monitoring to minimize misclassification errors can improve monitoring efficiency and conservation decision-making with considerable practical applications and benefits for species conservation.

FRAMEWORK FOR PROACTIVE MAINTENANCE PRACTICES FOR TRANSPORT INFRASTRUCTURES

AbstractThe intensive use, as well as climate change, accelerates structural deterioration of transport infrastructure, leading to an increased risk level. Hence, well‐founded procedures to improve asset management and optimize utilization of the limited resources for conservation are needed. The foreseen harmonization of standards at European level aims to facilitate the transition from traditional maintenance approaches (corrective and time‐based maintenance) towards a risk‐based approach to maintenance decision‐making. The condition‐based maintenance strategy is favored since enables early identification of risks. Analysis of best practices show that the acceptance and use of preventive maintenance strategies in the current practice is increasing. Therefore, it is essential to provide an harmonized basis for decision‐making concerning the implementation of maintenance strategies in asset management. This contribution summarizes the lessons learned and explores the vision developed in H2020 CSA IM‐SAFE project, which envisages the use of risk‐based maintenance management system and employing condition‐based maintenance strategies supported by inspection, testing and monitoring to ensure reliability, safety, availability and economical operation over the assets' lifetime.

Four steps to strengthen connectivity modeling

Maintaining and restoring ecological connectivity is considered a global imperative to help reverse the decline of biodiversity. To be successful, practitioners need to be guided by connectivity modeling research that is rigorous and reliable for the task at hand. However, the methods and workflows within this rapidly growing field are diverse and few have been carefully scrutinized. We propose four steps that should be consistently undertaken in connectivity modeling studies in order to improve rigour and utility: 1) describe the type of connectivity being modeled, 2) assess the uncertainty and sensitivity of model parameters, 3) validate the model outputs, ideally with independent data and 4) make non‐sensitive raw data and code openly available to enhance computational reproducibility. We reviewed the literature to determine the extent to which studies included these four steps. We focused on studies that generated novel landscape connectivity outputs using circuit theory and restricted our assessment to studies concerning terrestrial mammals. Among 181 studies meeting our search criteria, 39% communicated the type of connectivity being modeled, 18% conducted some form of sensitivity or uncertainty analysis (or both), 18% of studies attempted to validate their connectivity model outputs and only 7% used fully independent data to do so. Lastly, 13% of the studies made all raw data available, 2% provided all required code and only two studies provided both. Our findings highlight a clear need and opportunity to improve the reliability, reproducibility and utility of connectivity modeling research. We provide a checklist that researchers can consult and include with outputs. This will help practitioners make more informed decisions and ensure limited resources for connectivity conservation and restoration are allocated appropriately.

Whole-genome survey reveals extensive variation in genetic diversity and inbreeding levels among peregrine falcon subspecies.

In efforts to prevent extinction, resource managers are often tasked with increasing genetic diversity in a population of concern to prevent inbreeding depression or improve adaptive potential in a changing environment. The assumption that all small populations require measures to increase their genetic diversity may be unwarranted, and limited resources for conservation may be better utilized elsewhere. We test this assumption in a case study focused on the peregrine falcon (Falco peregrinus), a cosmopolitan circumpolar species with 19 named subspecies. We used whole-genome resequencing to generate over two million single nucleotide polymorphisms (SNPs) from multiple individuals of all peregrine falcon subspecies. Our analyses revealed extensive variation among subspecies, with many island-restricted and nonmigratory populations possessing lower overall genomic diversity, elevated inbreeding coefficients (F ROH)-among the highest reported, and extensive runs of homozygosity (ROH) compared to mainland and migratory populations. Similarly, the majority of subspecies that are either nonmigratory or restricted to islands show a much longer history of low effective population size (N e). While mutational load analyses indicated an increased proportion of homozygous-derived deleterious variants (i.e., drift load) among nonmigrant and island populations compared to those that are migrant or reside on the mainland, no significant differences in the proportion of heterozygous deleterious variants (i.e., inbreeding load) was observed. Our results provide evidence that high levels of inbreeding may not be an existential threat for some populations or taxa. Additional factors such as the timing and severity of population declines are important to consider in management decisions about extinction potential.

Conservation implications of a mismatch between data availability and demographic impact.

Cost-effective use of limited conservation resources requires understanding which data most contribute to alleviating biodiversity declines. Interventions might reasonably prioritise life-cycle transitions with the greatest influence on population dynamics, yet some contributing vital rates are particularly challenging to document. This risks managers making decisions without sufficient empirical coverage of the spatiotemporal variation experienced by the species. Here, we aimed to explore whether the number of studies contributing estimates for a given life-stage transition aligns with that transition's demographic impact on population growth rate, λ. We parameterised a matrix population model using meta-analysis of vital rates for the common eider (Somateria mollissima), an increasingly threatened yet comparatively data-rich species of seaduck, for which some life stages are particularly problematic to study. Female common eiders exhibit intermittent breeding, with some established breeders skipping one or more years between breeding attempts. Our meta-analysis yielded a breeding propensity of 0.72, which we incorporated into our model with a discrete and reversible 'nonbreeder' stage (to which surviving adults transition with a probability of 0.28). The transitions between breeding and nonbreeding states had twice the influence on λ than fertility (summed matrix-element elasticities of 24% and 11%, respectively), whereas almost 15 times as many studies document components of fertility than breeding propensity (n = 103 and n = 7, respectively). The implications of such mismatches are complex because the motivations for feasible on-the-ground conservation actions may be different from what is needed to reduce uncertainty in population projections. Our workflow could form an early part of the toolkit informing future investment of finite resources, to avoid repeated disconnects between data needs and availability thwarting evidence-led conservation.

Leveraging a century of fisheries surveys to prioritize conservation efforts for species in Great Plains streams of Oklahoma (USA)

Abstract Although non‐game fishes typically dominate lists of threatened and imperilled species, funding mechanisms for non‐game species are usually less robust than those for game species. This imbalance emphasizes the need for methodologies to identify imperilled species effectively and ensure efficient allocation of limited conservation resources. A database comprising >3,900 fisheries surveys conducted between 1905 and 2020 in Great Plains streams of Oklahoma (USA) was used to develop methodology for identifying species in need of conservation by assessing differences in species occurrences and trends in species ranges through time. Changes in occurrence for 92 species at both river catchment and ecoregion scales were assessed. Generalized linear models indicated significant differences between historical and contemporary fish communities at both scales. Univariate testing showed 84 instances of species occurrences changing in at least one catchment. Declines in occurrence were observed for eight species currently listed as species of greatest conservation need in Oklahoma and were used to identify five candidate species for listing. Family‐level trends in species occurrences suggested declines of native true minnow species and increases in generalist sunfishes and catfishes through time. Trends in detections within each hydrologic unit code sampled were used as a proxy for tracking changes in species range within each catchment. Various species were used as case studies to highlight this method. The results demonstrate how managers can apply an empirical methodology that extracts information from long‐term datasets to optimize conservation efforts for stream fishes and associated taxa.

Alien vs. Predator: Impacts of Invasive Species and Native Predators on Urban Nest Box Use by Native Birds.

Many bird species in Australia require tree hollows for breeding. However, assessing the benefits of urban nest boxes to native birds requires frequent monitoring that allows to assess nesting success. To better understand the benefits of nest boxes for native birds, we examined the impact of local habitat characteristics, invasive species (common myna, Acridotheres tristis), and native mammalian predators on urban nest box use and nesting success of native birds. We installed 216 nest boxes across nine locations in southeastern Australia (S.E. Queensland and northern New South Wales) in both long-invaded sites (invaded before 1970) and more recently invaded sites (after 1990). We monitored all boxes weekly over two breeding seasons. We recorded seven bird species and three mammal species using the nest boxes. Weekly box occupancy by all species averaged 8% of all boxes, with the species most frequently recorded in the nest boxes being the common brushtail possum (Trichosurus vulpecula), a native cavity user and nest predator. We recorded 137 nesting attempts in the boxes across all bird species. The most frequent nesting species were the invasive alien common mynas (72 nesting attempts). We recorded an average nesting failure rate of 53.3% for all bird species. We did not record any common mynas evicting other nesting birds, and found that several native species used the same box after the common myna completed its nesting. We recorded native possums in 92% of the boxes, and possum occupancy of boxes per site was negatively correlated with bird nesting success (p = 0.021). These results suggest that when boxes are accessible to invasive species and native predators, they are unlikely to significantly improve nesting opportunities for native birds. To ensure efficient use of limited conservation resources, nest boxes should be designed to target species of high conservation importance and limit other species of both predators and competitors.

Population genomics and conservation management of the threatened black-footed tree-rat (Mesembriomys gouldii) in northern Australia

Genomic diversity is a fundamental component of Earth’s total biodiversity, and requires explicit consideration in efforts to conserve biodiversity. To conserve genomic diversity, it is necessary to measure its spatial distribution, and quantify the contribution that any intraspecific evolutionary lineages make to overall genomic diversity. Here, we describe the range-wide population genomic structure of a threatened Australian rodent, the black-footed tree-rat (Mesembriomys gouldii), aiming to provide insight into the timing and extent of population declines across a large region with a dearth of long-term monitoring data. By estimating recent trajectories in effective population sizes at four localities, we confirm widespread population decline across the species’ range, but find that the population in the peri-urban area of the Darwin region has been more stable. Based on current sampling, the Melville Island population made the greatest contribution to overall allelic richness of the species, and the prioritisation analysis suggested that conservation of the Darwin and Cobourg Peninsula populations would be the most cost-effective scenario to retain more than 90% of all alleles. Our results broadly confirm current sub-specific taxonomy, and provide crucial data on the spatial distribution of genomic diversity to help prioritise limited conservation resources. Along with additional sampling and genomic analysis from the far eastern and western edges of the black-footed tree-rat distribution, we suggest a range of conservation and research priorities that could help improve black-footed tree-rat population trajectories at large and fine spatial scales, including the retention and expansion of structurally complex habitat patches.

Publication trends in global biodiversity research on protected areas

One of the main strategies to reduce the global loss of biodiversity has been the establishment of protected areas (PAs). High quality biodiversity knowledge is essential to successfully design PAs and PA networks, and to assess their conservation effectiveness. However, biodiversity knowledge is taxonomically and geographically biased. Even though PAs are typically more intensively surveyed than surrounding landscapes, they cannot avoid biodiversity knowledge shortfalls and biases. To investigate this, we performed a systematic literature review to assess publication trends in global biodiversity research taking place in PAs. Our data indicate that animals are more studied than plants, with vertebrates overrepresented in relation to invertebrates. Biodiversity in PAs has been mainly measured taxonomically (species richness or species diversity), while functional and phylogenetic diversity have rarely been considered. Finally, as predicted, there was a geographic bias towards European and USA terrestrial protected areas. These observed trends mirror more general studies of biodiversity knowledge shortfalls and could have direct negative consequences for conservation policy and practice. Reducing these biases and shortfalls is essential for more effective use of limited conservation resources.

Bridging the gap: Optimising connectivity solutions for an arboreal gliding mammal

Abstract Connectivity modelling tools are important for developing mitigation strategies to alleviate negative impacts on animal movement caused by road networks. Arboreal gliding mammals are especially vulnerable to road widening as they are unable to cross gaps beyond their gliding capacity. However, there are limitations of conventional raster‐based modelling techniques when applied on this group. We developed and applied a new model that quantifies the changes in connectivity for an arboreal gliding species, the Sunda colugo, in Singapore using information on species‐specific glide performance through a vector‐based approach. We also incorporated a genetic algorithm to determine optimal locations for sets of glide poles that could be installed to improve connectivity. Expectedly, connectivity was heavily impacted by the road widening works, with a 93.3% decrease in the total number of feasible glide paths connecting roadside trees. Nine glide poles installed during the construction phase of the project were initially uninformed by the connectivity model and they provided 26 additional connections only. Comparatively, the top nine pole locations identified through the genetic algorithm provided 247 additional connections, almost 10 times more than the amount supplied by the initial nine glide pole locations determined through qualitative methods. The multi‐objective capacity of the genetic algorithm also reduced large connectivity gaps post‐development, with simulated glide poles increasing the percentage of pixels covered with connectivity from 16.1% to 27.7%. Synthesis and applications. Our model fills a knowledge gap in connectivity modelling for arboreal gliding mammals whose movements are affected by varying habitat alterations. We demonstrated that locations of mitigation structures greatly influence the success of mitigation efforts and the locations can be optimised by incorporating the glide performance of the species into the genetic algorithm. Given limited conservation resources, this approach would benefit managers in formulating cost‐effective efforts for arboreal gliding mammals.

Biological mechanisms matter in contemporary wildlife conservation.

Given limited resources for wildlife conservation paired with an urgency to halt declines and rebuild populations, it is imperative that management actions are tactical and effective. Mechanisms are about how a system works and can inform threat identification and mitigation such that conservation actions that work can be identified. Here, we call for a more mechanistic approach to wildlife conservation and management where behavioral and physiological tools and knowledge are used to characterize drivers of decline, identify environmental thresholds, reveal strategies that would restore populations, and prioritize conservation actions. With a growing toolbox for doing mechanistic conservation research as well as a suite of decision-support tools (e.g., mechanistic models), the time is now to fully embrace the concept that mechanisms matter in conservation ensuring that management actions are tactical and focus on actions that have the potential to directly benefit and restore wildlife populations.

The contrary conservation situations of two local critically endangered species, Vaccinium emarginatum (Ericaceae) and Elatostema platyphyllum (Urticaceae), growing on the eastern edge of the distribution

As biodiversity loss continues, there is an urgent need to develop efficient conservation measures to protect diversity with limited conservation resources. Conservation targets have generally been selected based on their population size, but more detailed assessments clarifying the phylogenetic genetic status, history, and phylogenetic uniqueness of rare species is crucial to set more appropriate and effective conservation measures. In Japan, the Act on Conservation of Endangered Species of Wild Fauna and Flora designated endangered plants with high conservation priority, but >40% of these species also grow overseas. We conducted comparative analyses based on ddRADseq and MIG-seq to evaluate the population conservation status and value of Vaccinium emarginatum and Elatostema platyphyllum which are growing across national borders at the eastern edge of their species distribution range. The analyses revealed contrasting conservation status between the two species; the Japanese population of V. emarginatum had lower genetic diversity at the individual level and phylogenetically differentiated from Taiwanese populations, while that of E. platyphyllum had higher diversity at the individual level and is a relatively recent migrant with little phylogenetical differentiation from Taiwanese populations. The two species, which share the common feature of being critically rare in Japan, showed contrasting genetic/phylogenetic characteristics. This study provided useful information for appropriate conservation measures based on species’ phylogenetic traits and genetic diversity.

Identifying seasonal differences in migration characteristics of Oriental white stork (Ciconia boyciana) through satellite tracking and remote sensing

Migratory species interact with different ecosystems in different regions during migration, making them more environmentally sensitive and therefore more vulnerable to extinction. Long migration routes and limited conservation resources desire clear identification of conservation priorities to improve the allocation efficiency of conservation resources. Clarifying the spatio-temporal heterogeneity of the utilization intensity during migration is an effective way to guide the conservation areas and priority. 12 Oriental White Storks (Ciconia boyciana), listed as an “endangered” species by the IUCN, were equipped with satellite-tracking loggers to record their hourly location throughout the year. Then, combined with remote sensing and dynamic Brownian Bridge Movement Model (dBBMM), characteristics and differences between spring and autumn migration were identified and compared. Our findings revealed that: (1) the Bohai Rim has always been the core stopover area for the Storks’ spring and autumn migration, but the utilization intensity has spatial differences; (2) differences in habitat selection resulted in differences in the Storks’ spatial distribution, thus affecting the efficiency of existing conservation systems; (3) the shift of habitat from natural wetlands to artificial surfaces calls for the development of eco-friendly land use mode; (4) the development of satellite tracking, remote sensing, and advanced data analysis methods have greatly facilitated movement ecology, even though they are still under development.

Prioritising the eradication of invasive species from island archipelagos with high reinvasion risk

Abstract Eradicating invasive species from islands is a proven method for safeguarding threatened and endangered species from extinction. Island eradications can deliver lasting benefits, but require large up‐front expenditure of limited conservation resources. The choice of islands must therefore be prioritised. Numerous tools have been developed to prioritise island eradications, but none fully account for the risk of those eradicated species later returning to the island: reinvasion. In this paper, we develop a prioritisation method for island eradications that accounts for the complexity of the reinvasion process. By merging spatially explicit metapopulation modelling with stochastic dynamic optimisation techniques, we construct a decision‐support tool that optimises conservation outcomes in the presence of reinvasion risk. We applied this tool to two different case studies—rat (Rattus rattus) invasions in the Seaforth archipelago in New Zealand, and cane toad (Rhinella marina) invasions in the Dampier archipelago in Australia—to illustrate how state‐dependent optimal policies can maximise expected conservation gains. In both case studies, incorporating reinvasion risk dramatically altered the optimal order of island eradications, and improved the potential conservation benefits. The increase in benefits was larger in Dampier than Seaforth (42% improvement versus 6%), as a consequence of both the characteristics of the invasive species, and the arrangement of the islands. Synthesis and applications. Our results illustrate the potential consequences of ignoring reinvasion risk. We recommend that reinvasion risk be explicitly included in any island eradication prioritisation involving an archipelago, particularly when some islands are close to the mainland.

Habitat amount or landscape configuration: Emerging HotSpot analysis reveals the importance of habitat amount for a grassland bird in South Dakota.

Habitat loss and fragmentation are two important drivers of biodiversity decline. Understanding how species respond to landscape composition and configuration in dynamic landscapes is of great importance for informing the conservation and management of grassland species. With limited conservation resources, prescribed management targeted at the appropriate landscape process is necessary for the effective management of species. We used pheasants (Phasianus colchicus) across South Dakota, USA as a model species to identify environmental factors driving spatiotemporal variation in population productivity. Using an emerging Hotspot analysis, we analyzed annual count data from 105 fixed pheasant brood routes over a 24-year period to identify high (HotSpot) and low (ColdSpot) pheasant population productivity areas. We then applied classification and regression tree modeling to evaluate landscape attributes associated with pheasant productivity among spatial scales (500 m and 1000 m). We found that the amount of grassland at a local spatial scale was the primary factor influencing an area being a HotSpot. Our results also demonstrated non-significant or weak effects of fragmentation per se on pheasant populations. These findings are in accordance with the habitat amount hypothesis highlighting the importance of habitat amount in the landscape for maintaining and increasing the pheasant population. We, therefore, recommend that managers should focus on increasing the total habitat area in the landscape and restoring degraded habitats. Our method of identifying areas of high productivity across the landscape can be applied to other species with count data.

Spatiotemporal analysis of deforestation patterns and drivers reveals emergent threats to tropical forest landscapes

As deforestation breaches into new tropical frontiers, proactive conservation strategies require a trifecta of information on where deforestation is accelerating (emergent), how drivers of deforestation vary spatiotemporally, and where to focus limited conservation resources in protecting the most integral yet threatened forested landscapes. Here we introduce Emergent Threat Analysis, a process integrating Emerging Hot Spot Analysis of deforestation, visual classification of deforestation outcomes over time, and spatial quantification of contemporary forest condition. We applied Emergent Threat Analysis to tropical Southeast Asia, a global epicentre of biodiversity threatened by deforestation. We found that emergent hot spots (EHS)—a subset of hot spots characterized by strong, recent, and clustered patterns of deforestation—accounted for 26.1% of total forest loss from 1992 to 2018, with deforestation within EHS proceeding at 2.5 times the regional rate of gross loss. Oil palm and rubber plantation expansion were the principal drivers of deforestation within EHS of insular and mainland SE Asia, respectively. Over the study period, oil palm shifted in importance from Sumatra and Sarawak to Papua and Kalimantan, whereas rubber became prominent in Cambodia and Tanintharyi from 2006 to 2015. As of 2019, more than 170 000 km2 of SE Asia’s remaining forest occurred within EHS, of which 21.7% was protected. High and medium-integrity forest constituted 19.2% and 49.1% of remaining EHS forest, respectively, but of these, 35.0% of high-integrity and 23.9% of medium-integrity EHS forest were protected. Because we anticipate that tree plantation expansion will continue to drive deforestation in SE Asia, significantly heightened protection is needed to secure the long-term preservation of high and medium-integrity forest, especially in highly contested forest frontier regions. Finally, as a flexible, integrated process, Emergent Threat Analysis is applicable to deforestation fronts across the global tropics.

Generating unbiased estimates of burrowing seabird populations

Maximising survey efficiency can help reduce the tradeoff between spending limited conservation resources on identifying population changes and responding to those changes through management. Burrow‐nesting seabirds are particularly challenging to survey because nests cannot be counted directly. We evaluated a stratified random survey design for generating unbiased population estimates simultaneously for four petrel species nesting on Macquarie Island, Australia, where the survey cue, burrow entrances, is similar for all species. We also compared the use of design‐based and model‐based analyses for minimising uncertainty in estimates. We recorded 2845 Antarctic prion burrows, 306 white‐headed petrel burrows and two blue petrel burrows while distance‐sampling along 154 km of transects. For blue petrels and grey petrels, we completed nocturnal searches along a further 71 km and searched 249 km of tracks during follow‐up ground searches. We failed to generate unbiased population estimates for two rare and localised species, blue and grey petrels, from our stratified random survey. Only for the most widespread and abundant species, Antarctic prion, did the estimate have reasonable power to detect a rapid population change. Model‐based analyses of the stratified random survey data did not improve upon traditional design‐based analyses in terms of uncertainty in population estimates, but they did provide useful spatial representation of current populations. Models that used the targeted survey data did not reflect current population sizes and distributions of the two rare and localised species. We found that when species ecologies, distributions and abundances vary, a multi‐method approach to surveys is needed. Species with low abundance that occur patchily across large islands are likely to be best estimated using targeted surveys, whereas widespread and abundant species can be accurately and precisely estimated from randomised surveys using informative model‐based analyses.

Assessing freshwater fish biodiversity of Kumbe River, Papua (Indonesia) through environmental DNA metabarcoding

Context The ability to accurately assess biodiversity is a critical first step towards effective conservation and management. However, assessment of biodiversity using conventional monitoring programs is often constrained by high cost and a lack of taxonomic expertise. Environmental DNA (eDNA) metabarcoding may be a useful tool to efficiently catalogue biodiversity in areas that cannot be easily assessed using other methods. Aims Here, we evaluated the potential of eDNA metabarcoding for assessing fish biodiversity and distribution in the Kumbe River, Papua Province, Indonesia. Methods We selected four sampling locations and collected seven eDNA samples from each location. We used eDNA metabarcoding of the Cytochrome-b gene to characterise the fish community. Key results A total of 23 species were detected, three of which comprised 92% of sequence reads detected: Melanotaenia goldiei (32%), Craterocephalus randi (31%), and the invasive tilapia Oreochromis niloticus (29%). Only five species that were previously detected using conventional methods were detected by metabarcoding: M. goldiei, Craterocephalus stercusmuscarum, O. niloticus, Neoarius graeffei, and Arius arius. We detected 18 species (70% native) that have never been recorded from the Kumbe River. Conclusions This work has demonstrated that fish biodiversity is substantially underestimated in the Kumbe River. Environmental DNA metabarcoding is a promising rapid, non-invasive and cost-effective method for assessing fish biodiversity in Papua. Implications The findings support future investment in eDNA metabarcoding to characterise the fish biodiversity in Papua. This will assist in allocating the limited resources for conservation and management to areas most at risk from anthropogenic impacts.