H. Resit Akcakaya

H. Resit Akcakaya
Stony Brook University | Stony Brook · Department of Ecology and Evolution

Ph.D.

About

245
Publications
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Introduction
I am a conservation biologist with expertise in population and metapopulation dynamics, modelling, and extinction risk assessment. My current research focuses on quantifying species recovery and conservation success; measuring the range of a species; deciding when to list a species as Extinct; and assessing the vulnerability of species to climate change. More information at: https://akcakaya.weebly.com/ and https://scholar.google.com/citations?hl=en&user=RMg7RqkAAAAJ

Publications

Publications (245)
Article
Species interactions matter to conservation. Setting an ambitious recovery target for a species requires considering the size, density, and demographic structure of its populations such that they fulfill the interactions, roles, and functions of the species in the ecosystems in which they are embedded. A recently proposed framework for an Internati...
Article
Full-text available
Historical data are a valuable resource for addressing present-day conservation issues, for example by informing the establishment of appropriate recovery targets. However, while the recovery of threatened species is the end goal of many conservation programmes, data made available through the efforts of palaeoecologists and historical ecologists a...
Article
Full-text available
Stopping declines in biodiversity is critically important, but it is only a first step toward achieving more ambitious conservation goals. The absence of an objective and practical definition of species recovery that is applicable across taxonomic groups leads to inconsistent targets in recovery plans and frustrates reporting and maximization of co...
Article
Extinction of a species is difficult to detect, yet there are important conservation consequences of classifying an extant species as extinct or an extinct species as extant, and potentially significant costs of making the wrong classification. To deal with the uncertainties of detecting extinctions, some Critically Endangered species are tagged as...
Article
Full-text available
Averting human‐induced extinctions will require strong policy commitments that comprehensively address threats to species. A new Global Biodiversity Framework is currently being negotiated by the world’s governments through the Convention on Biological Diversity. Here we explored how the suggested targets in this framework could contribute to reduc...
Article
Full-text available
Medicinal plants contribute substantially to the well-being of people in large parts of the world, providing traditional medicine and supporting livelihoods from trading plant parts, which is especially significant for women in low-income communities. However, the availability of wild medicinal plants is increasingly threatened; for example, the Na...
Article
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species is central in biodiversity conservation, but insufficient resources hamper its long-term growth, updating, and consistency. Models or automated calculations can alleviate those challenges by providing standardised estimates required for assessments, or prioriti...
Article
Full-text available
Pathways to extinction start long before the death of the last individual. However, causes of early stage population declines and the susceptibility of small residual populations to extirpation are typically studied in isolation. Using validated process-explicit models, we disentangle the ecological mechanisms and threats that were integral in the...
Article
Full-text available
The cover image is based on the Letter Process‐explicit models reveal pathway to extinction for woolly mammoth using pattern‐oriented validation by Damien A. Fordham et al., https://doi.org/10.1111/ele.13911. Image Credit: Mauricio Anton.
Article
Full-text available
Species with large local abundances tend to occupy more sites. One of the mechanisms proposed to explain this widely reported inter-specific relationship is a cross-scale hypothesis based on dynamics at the population level. Called the vital rates mechanism; it uses within-population demographic processes of population growth and density dependence...
Article
Forecasting changes in size and distributions of populations is an essential component of conservation assessments. Such forecasts are only useful for species conservation and management when they are based on robust estimators of fecundity, survival, and density dependence. While apparent survival estimation is the main focus of mark–recapture mod...
Article
Full-text available
Robust evaluation of the impact of biodiversity conservation actions is important not only for ensuring that conservation strategies are effective and maximise return on investment, but also to identify and celebrate successful conservation strategies. This evaluation can be retrospective (comparing the current situation to a counterfactual scenari...
Article
Full-text available
Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 s...
Article
Full-text available
Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 s...
Article
Full-text available
Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 s...
Article
Full-text available
Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a “Green List of Species” (now the IUCN Green Status of Species). A draft Green Status framework for assessing species’ progress toward recovery, published in 2018, proposed 2 s...
Article
Full-text available
Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 s...
Article
Full-text available
Frogs have been harvested from the wild for the last 40 years in Turkey. We analysed the population dynamics of Anatolian water frogs ( Pelophylax spp.) in the Seyhan and Ceyhan Deltas during 2013–2015. We marked a total of 13,811 individuals during 3 years, estimated population sizes, simulated the dynamics of a harvested population over 50 years,...
Article
Full-text available
Population reductions are often used to assess extinction risk of species in the IUCN Red List. Guidelines for Red List assessments describe specific methods for calculating the amount of reduction for species with strongly fluctuating populations. Recently, an alternative approach that involves expert opinion has been suggested for calculating pop...
Preprint
Full-text available
Processes leading to the megafauna extinctions of the late Pleistocene and early-Holocene are uncertain, with intense debate on the roles of human hunting and climatic change. Using process-explicit simulations of climate-human-woolly mammoth interactions, which integrate spatiotemporal evidence from fossils and ancient DNA, we show that humans acc...
Preprint
Full-text available
Stopping human-induced extinctions will require strong policy commitments that comprehensively address threats to species. In 2021, a new Global Biodiversity Framework will be agreed by the Convention on Biological Diversity. Here we investigate how the suggested targets could contribute to reducing threats to threatened vertebrates, invertebrates,...
Preprint
Full-text available
Species with large local abundances tend to occupy more sites. One of the mechanisms proposed to explain this widely reported inter-specific relationship is a cross-scale hypothesis based on dynamics at the population level. Called the vital rates mechanism, it uses within-population demographic processes of population growth and density dependence...
Preprint
Full-text available
Forecasting changes in size and distributions of populations is at the forefront of ecological sciences in the 21st century. Such forecasts require robust estimators of fecundity, survival and density-dependence. While survival estimation is the main focus of mark-recapture modelling, fecundity and density dependence are rarely the subject of these...
Article
Targets for human development are increasingly connected with   targets for nature, however, existing scenarios do not explicitly address this relationship. Here, we outline a strategy to generate scenarios centred on our relationship with nature to inform decision-making at multiple scales.
Article
Birds have been comprehensively assessed on the International Union for Conservation of Nature (IUCN) Red List more times than any other taxonomic group. However, to date, generation lengths have not been systematically estimated to scale population trends when undertaking assessments, as required by the criteria of the IUCN Red List. We compiled i...
Article
Full-text available
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species includes assessment of extinction risk for 98 512 species, plus documentation of their range, habitat, elevation, and other factors. These range, habitat and elevation data can be matched with terrestrial land cover and elevation datasets to map the species' ar...
Article
Full-text available
Assessing species' vulnerability to climate change is a prerequisite for developing effective strategies to conserve them. The last three decades have seen exponential growth in the number of studies evaluating how, how much, why, when, and where species will be impacted by climate change. We provide an overview of the rapidly developing field of c...
Article
Full-text available
Targets for human development are increasingly connected with targets for nature, however, existing scenarios do not explicitly address this relationship. Here, we outline a strategy to generate scenarios centred on our relationship with nature to inform decision-making at multiple scales.
Article
Extinctions are important indicators of biodiversity status. When they are detected, they may trigger the redirection of conservation resources to save other species. Yet declaring extinctions is inherently uncertain. Relevant evidence for consideration includes information on threats, the time series of species records and the effort employed to s...
Article
Full-text available
Assessments of risk to biodiversity often rely on spatial distributions of species and ecosystems. Range size metrics used extensively in these assessments, such as Area of Occupancy (AOO), are sensitive to measurement scale, prompting proposals to measure them at finer scales, or a variery of different scales based on the shape of the distribution...
Data
Habitat Suitability Model for Jaguar in the Upper Paraná River Corridor. (PDF)
Article
Full-text available
Loss of Arctic sea ice owing to climate change is the primary threat to polar bears throughout their range. We evaluated the potential response of polar bears to sea-ice declines by (i) calculating generation length (GL) for the species, which determines the timeframe for conservation assessments; (ii) developing a standardized sea-ice metric repre...
Article
Full-text available
Jaguar (Panthera onca) populations in the Upper Parana River in the Brazilian Atlantic Forest region, live in a landscape that includes highly fragmented areas as well as relatively intact ones. We developed a model of jaguar habitat suitability in this region, and based on this habitat model, we developed a spatially structured metapopulation mode...
Article
Full-text available
Uses of long-term ecological proxies in strategies for mitigating future biodiversity loss are too limited in scope. Recent advances in geochronological dating, palaeoclimate reconstructions and molecular techniques for inferring population dynamics offer exciting new prospects for using retrospective knowledge to better forecast and manage ecologi...
Article
Full-text available
Uses of long-term ecological proxies in strategies for mitigating future biodiversity loss are too limited in scope. Recent advances in geochronological dating, palaeoclimate reconstructions and molecular techniques for inferring population dynamics offer exciting new prospects for using retrospective knowledge to better forecast and manage ecologi...
Article
Full-text available
Climate conditions, such as temperature or precipitation averaged over several decades strongly affect species distributions, as evidenced by experimental results and a plethora of models demonstrating statistical relations between species occurrences and long-term climate averages. However, long-term averages can conceal climate changes that have...
Technical Report
Full-text available
The prospect of species “de-extinction”, defined as the process of creating an organism that resembles an extinct species (but see Note on Terminology below) has moved from science fiction to plausibility within the last decade, but has been debated widely only within the last few years. The increasing public profile of species “de-extinction” has...
Article
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The identification of species at risk of extinction is a central goal of conservation. As the use of data compiled for IUCN Red List assessments expands, a number of misconceptions regarding the purpose, application and use of the IUCN Red List categories and criteria have arisen. We outline five such classes of misconception; the most consequentia...
Article
Population viability analysis is widely used for assessing population-level impacts of environmental changes on species. When combined with sensitivity analysis, PVA yields insights into the effects of parameter and model structure uncertainty. This helps researchers to prioritize efforts for further data collection so that model improvements are e...
Article
Stochastic simulation models requiring many input parameters are widely used to inform the management of ecological systems. The interpretation of complex models is aided by global sensitivity analysis, using simulations for distinct parameter sets sampled from multidimensional space. Ecologists typically analyze such output using an “emulator”; th...
Article
Full-text available
Two processes for regional environmental assessment are currently underway: the Global Environment Outlook (GEO) and Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES). Both face constraints of data, time, capacity, and resources. To support these assessments, we disaggregate three global knowledge products according to their...
Article
Full-text available
Population trends play a large role in species risk assessments and conservation planning, and species are often considered threatened if their recent rate of decline meets certain thresholds, regardless how large the population is. But how reliable an indicator of extinction risk is a single estimate of population trend? Given the integral role th...
Article
Full-text available
Extent of Occurrence (EOO) is a key metric in assessing extinction risk using the IUCN Red List categories and criteria. However, the way in which EOO is estimated from maps of species' distributions is inconsistent between assessments of different species, and between major taxonomic groups. It is often estimated from the area of mapped distributi...
Article
Full-text available
Context Threats to wildlife species from extreme events, such as droughts, are predicted to increase in frequency and magnitude with climate change. Extreme events can cause mortality and community-level changes, but for some mobile species, movement away from areas affected may be a viable option. Objectives We examined the effect of extreme weath...
Article
Full-text available
Exploited fish populations frequently exhibit truncated age-structure. To address a basic question in fisheries science and conservation biology—how does age truncation affect population dynamics and productivity?—we explored the effect of age-structure on recruitment dynamics of ten stocks of Atlantic cod (Gadus morhua). Based on six alternative s...
Article
Full-text available
The effects of climate change on biodiversity are increasingly well documented, and many methods have been developed to assess species' vulnerability to climatic changes, both ongoing and projected in the coming decades. To minimize global biodiversity losses, conservationists need to identify those species that are likely to be most vulnerable to...
Article
Recent studies show that current IUCN Red List assessment methods can identify species vulnerable to extinction because of climate change. But species must be assessed more completely and more regularly, and adaptation actions initiated swiftly once threatened species are identified.
Article
Climate change is likely to become an increasingly major obstacle to slowing the rate of species extinctions. Several new assessment approaches have been proposed for identifying climate-vulnerable species, based on the assumption that established systems such as the IUCN Red List need revising or replacing because they were not developed to explic...
Conference Paper
Background/Question/Methods Simulation models for projecting regional abundance and range dynamics are indispensible tools for assessing the biodiversity consequences of global change. Increasingly, many of the mechanisms and interactions that drive species distributions are modeled explicitly, yielding key insights for ecology and conservation in...
Conference Paper
Predicting the response of plant populations to climate change requires integrating habitat relationships, dispersal patterns, and population dynamics. We developed and applied integrated models of plant metapopulations, linking ecological niche (species distribution) models and demographic models. These models allow exploring species level respons...
Conference Paper
Background/Question/Methods Identifying species vulnerable to climate change remains a challenging task for conservation biologists. Several new assessment approaches have been proposed for doing this, based on the assumption that established assessments such as the IUCN Red List need revising or replacing because they have not explicitly conside...