Conservation Letters最新文献

Understanding habitat fragmentation effects on wildlife is critical to promoting effective conservation practices. There are many metrics of habitat fragmentation, from simple (number of habitat patches) to complex metrics designed to summarize many aspects of landscape patterns. To make meaningful inferences, we must understand how complex metrics are related to landscape patterns, especially to habitat amount. Here, we examine the behavior of the Edge Influence index, a metric that has been used in several influential recent studies and is designed to assess fragmentation and edge effects. Contrary to expectation, this index does not primarily quantify fragmentation or edge but rather habitat amount. Therefore, researchers should take this into consideration when interpreting the results of studies based on the Edge Influence index. To guide meaningful conservation action in fragmented landscapes, we recommend using simple, direct measures of fragmentation and separating the effects of habitat configuration from the effects of habitat amount.

Invasive species disrupt biological communities, but lethal control of invaders often meets staunch resistance, posing a conundrum for policymakers. For instance, the human-mediated spread of barred owls from eastern to western North America threatens numerous native species—including the iconic and listed spotted owl—spurring intense debate about whether to lethally control this charismatic but invasive species. A recent US Fish and Wildlife Service strategy, in particular, has drawn strong criticism based on untested claims that barred owl control is unscalable and doomed to failure. Contrary to such claims, we conducted successful lethal controls across >50,000 km² in California, removing 3373 barred owls—around one third of the state's current population. Critically, monitoring revealed that removals stabilized spotted owl populations and halted the establishment of barred owls. Our work provides direct support for the federal strategy to address this pressing issue and highlights general strategies to maximize conservation while minimizing invader killing.

Eroding perceptions of biodiversity present a significant challenge for conservation. If younger generations see current degraded states as “natural,” goals for conservation actions may not be ambitious enough, and public support may be compromised. Historical data can provide context for fully appreciating the extent of biodiversity loss. We utilize the most species-rich day of each year in North America's longest running butterfly monitoring program's most diverse site to examine how perceptions of peak butterfly richness could shift over time. In early monitoring years, days with over 50 observed species were standard, but now peak richness days have shifted over time, such that these days now see ten fewer species. High-diversity days shape perceptions of biodiversity, and we provide an example of how long-term monitoring data can be utilized to study shifting baselines in observer perceptions of biodiversity and to contextualize current observations.

Using military-type strategies and equipment to conserve wildlife, also known as militarized conservation, is highly contested. In sub-Saharan Africa (SSA), one acutely controversial aspect of militarized conservation is when armed rangers shoot at suspected criminals inside protected and conserved areas (PCAs). We quantified perceptions among members of eight international publics on the acceptability of this particularly contentious aspect of militarized conservation, testing whether acceptability depended on the specific crime rangers suspect people of committing. Overall, acceptability of rangers shooting at suspected criminals inside PCAs in SSA was low across all eight publics, but acceptability was generally higher among participants living further away from PCAs in SSA than those living closer to PCAs in SSA. Shooting in self-defense and to prevent poaching were consistently most acceptable across all eight publics. Our findings contribute new comparative evidence about international public perceptions of a very sensitive aspect of PCA management in SSA. This evidence may be useful to decision-makers balancing competing pressures to protect biodiversity, respect local values, and operate with legitimacy in an international context. Our findings are especially relevant in light of international aspirations to simultaneously increase PCAs while respecting the rights and interests of people living in high-biodiversity areas.

Global responses to climate change vary across ecosystems. Identifying coral reefs that can persist despite extreme warming is crucial for guiding research, policy, and management. Resilience frameworks recommend protecting potential reef sanctuaries with specific attributes, including climate avoidance, rapid recovery, or resistance. However, climate-avoidant reefs are dwindling, and recovery times are lengthening. We propose that resistance should be the cornerstone of reef resilience planning. A literature synthesis reveals that the definition and application of “reef resistance” are highly variable, limiting its effectiveness in management and policy. Over 85% of sources suggest that evolutionary processes contribute to resistance, but there is considerable variability in other cited ecological factors. We highlight a mismatch between implied mechanisms and actual data, with only ∼25% of studies linking resistance to relevant coral adaptation or acclimatization data. To address this, we propose a standardized definition of heat-resistant reefs based on adaptation and acclimatization principles: reefs characterized by corals whose underlying genetics enable survival beyond previous thermal limits. This approach will enhance the effective allocation of limited resources for measuring, protecting, and managing reefs, as we strive to halt the human-induced emissions driving their decline.

New tools of synthetic biology that enable precise manipulation of genomes, metabolic pathways, and ecosystems present new opportunities, risks, ethical dilemmas, and responsibilities for stewards of biodiversity. We argue that the risks and benefits of synthetic biology for use in biodiversity conservation, which we term “synthetically assisted conservation,” can be better understood, evaluated, and regulated by precisely defining the techniques in relation to well-established and regulated conservation frameworks: conservation translocation and integrated pest management. Synthetically assisted conservation translocation could include the release of genetically modified organisms for in situ conservation of genes or restoration of ecological functions, while a synthetically assisted application of integrated pest management could involve using genetic modifications propagated through gene drives to remove invasive species. Contextualizing the range of techniques as expansions of these frameworks clarifies how new approaches may impact conservation, facilitating risk assessment and responsible implementation. Decision-making may be informed by existing policy guidance in accordance with national and international regulations on conservation translocation and integrated pest management. Nevertheless, additional policy and evaluative guidelines are needed to keep pace with rapid technological growth and novel issues such as the release of genes (e.g., in pollen or marine-dispersed gametes) separate from live organisms.

Fish maw, the dried swim bladder of teleost fish, is consumed throughout much of East and Southeast Asia. The serving of maw is seen as an indicator of wealth, prestige, and status in Chinese culture. While Hong Kong and mainland China are considered major fish maw importers, its trade in these countries remains largely understudied. This lack of research is even more apparent throughout Southeast Asia where fish maw is widely available and frequently consumed. Here, we perform the first molecular survey of the maw trade in Singapore and Malaysia to identify the species of fish involved. Both countries are significant global importers, consumers, and re-exporters of maw. We collected 503 maw samples from products that ranged in price from $59 to $53,375 per kg dried weight. We identified a number of endangered species and suggest that a Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) listing be implemented on a number of species to avoid trade incompatible with their continued persistence. Reflecting the limited research into the conservation status of marine fish, we find a high proportion of the identified samples assessed as data deficient or not evaluated.

The Kunming-Montreal Global Biodiversity Framework commits nations to conserving 30% of coastal and marine areas, “especially areas of particular importance for biodiversity.” Key Biodiversity Areas (KBAs) provide a standardized approach for recognizing sites holding a significant proportion of the global population or extent of species or ecosystems. However, concerns about the relevance of this approach for broadly distributed and/or highly mobile aquatic vertebrates prompted development of parallel approaches focused on critical areas for life-history processes, including Important Shark and Ray Areas (ISRAs). We examine these approaches and assess whether important areas for sharks, rays, and chimaeras (“sharks”) can qualify as KBAs, by applying the KBA criteria to ISRAs. One fifth of ISRAs could be recognized as KBAs. KBAs could be recognized for three quarters of globally threatened and two thirds of non-threatened restricted-range sharks based on published range maps. For broadly distributed species, additional information (e.g., on aggregations) is needed to recognize important sites as KBAs. Our results show that these approaches are complementary, highlighting the potential for ISRAs to contribute to KBA assessments while ensuring important sites for sharks are mapped and available to inform government actions to meet global commitments for conserving biodiversity in coastal and marine areas.

The ongoing biodiversity crisis highlights the need for targeted conservation efforts, yet the focus often remains on rare and endangered species. This overlooks the vital role of common species, which are the ecological backbone of ecosystems, supporting the stability and functioning of biodiversity. We argue that common species, especially their population dynamics and potential tipping points, are too often neglected and that their conservation is urgent. We illustrate this issue using bats (Chiroptera) as a model. This diverse mammalian order features key ecosystem service providers, including insectivores, pollinators, and seed dispersers. Bats are sensitive to anthropogenic pressures, and many species, including common ones, face population declines and the impact of ecosystem disruption. Research and conservation must urgently be expanded to include common species. Through case studies, we demonstrate how common bat species are indicators of environmental changes and the urgent need to monitor their populations. We provide recommendations for improving research, enhancing conservation policies, and adopting a more inclusive framework acknowledging the indispensable role of common species in ecosystem services and biodiversity.

Wildlife use and trade support the livelihoods of millions of people worldwide but also threaten thousands of species. Legal instruments, when effectively designed and implemented, can help regulate trade and mitigate negative impacts. However, activities along supply chains are rarely categorically legal or illegal, with considerable uncertainties regarding legality in the wildlife trade. These uncertainties can compromise the success of efforts to ensure, or improve, sustainability, but are often overlooked. Here, we categorize legal uncertainties in wildlife trade into three dimensions: institutional, operational, and perceptual. We explore their implications for sustainable management and discuss potential interventions to address them, drawing on examples from wildlife management and other sectors. Resolving these uncertainties can reduce unsustainable and illegal trade, strengthen traceability and enforcement, and promote equitable benefit-sharing among actors. Our findings offer actionable insights for policymakers, practitioners, and researchers to improve the clarity and effectiveness of wildlife trade management, advancing both conservation and socio-economic objectives.