Conservation Letters最新文献

Tropical seagrass ecosystems are globally imperiled due to overfishing and anthropogenic disturbances. Sustaining the services they provide will require managing resilience, particularly with increased volatility from climate change. Portfolio theory is touted as a mechanism to increase resilience in ecosystems because it takes advantage of temporal volatility in local production dynamics to increase stability at larger spatial scales. Using an individual-based model of a network of artificial reefs across multiple seagrass ecosystems that is parameterized with 15 years of field data, we demonstrate that (1) the large fish populations and the low enrichment synergistically increase portfolio effects; (2) the mechanism was via reduced local and increased meta-ecosystem stability in primary production; and (3) stability was greatest under intermediate production because nutrient enrichment reduces and fish, which have less influence on the amount of production, promote stability. Integrating common-sense management with portfolio theory can stabilize the services provided by seagrass ecosystems.

The harvest and sale of wildlife can drive species to extinction when consumers are willing to pay high prices for the last harvested individuals of a very rare species, a phenomenon known as the anthropogenic Allee effect (AAE). Because demand for rarity is an inherent human desire, the AAE has the potential to affect a wide range of exploited species across several geographic regions. Here, we assess the current extent of empirical evidence for the AAE, how such evidence has been measured, and how this evidence interfaces with existing models of the AAE. We find substantial gaps in the empirical evidence base for the AAE and suggest that this deficit prevents assessment of the AAE in species extinctions. We provide a framework for generating empirical evidence that can identify when the AAE is likely occurring or has the potential to occur in the future, and recommend directions for both empirical and theoretical modeling research designed to strengthen our ability to forecast the ecological and market conditions that result in an AAE.

Indigenous lands are increasingly recognized for their critical role in biodiversity conservation. However, concerns persist about the sustainability of hunting practices within these territories. This study investigates the long-term impact of Indigenous hunting practices on wildlife populations in the Cofán territory of Zábalo, Ecuador. We employed line transect surveys to estimate wildlife densities over three periods (2001–2003, 2006–2009, and 2018), focusing on 16 species that are integral to local livelihoods and subject to community management. Our results indicate generally stable or increasing populations for most species, particularly in nonhunted areas, where spatial restrictions are enforced. The Cofán's ability to sustainably manage relations between humans and wildlife is largely attributable to their adaptive management system, which includes species-specific regulations and spatial zoning, and is realized through community decision-making, knowledge sharing, and an ethos of care. These findings demonstrate that Indigenous stewardship can effectively sustain biodiversity in complex biocultural systems. The study underscores the importance of integrating Indigenous knowledge with scientific approaches to achieve long-term conservation goals.

Incentives are a widely used tool for addressing deforestation and are often implemented as collective contracts. Local institutions are crucial to the solution of collective action problems associated with forest conservation, but we still have little knowledge of how to encourage institutional creation through policy. Since collective contracts do not eliminate freeriding incentives, we argue that their success hinges on their ability to stimulate the creation of institutions for collective action. To test these ideas, we analyze data from an incentivized lab-in-the-field experimental collective action game played with natural resource users in four developing countries. The experiment simulates management of a common forest, and groups were randomly assigned to a conservation incentive payment condition. We observe how much group members attempt to coordinate on the creation of institutional rules and find experimental evidence that an external incentive program can stimulate the endogenous creation of informal institutions.

It is widely accepted that populations of terrestrial predators sometimes contain “problem individuals” that repeatedly attack humans, yet this phenomenon has never been demonstrated in sharks. Here, we present photographic and genetic evidence of individuals in populations of tiger Galeocerdo cuvier and oceanic whitetip Carcharhinus longimanus sharks that (1) demonstrated atypical behavior compared to the rest of the population, (2) engaged in repeated agonistic behavior directed toward humans, and (3) bit, or attempted to bite humans in probable foraging attempts. These case studies provide some of the first evidence for the existence of “problem individuals” among sharks. The percentage of fatalities due to the same shark individual are not known, so we recommend systematic swabbing of shark bite victims wounds to better understand the importance of this phenomenon and the possibility of identifying these animals. Environmentally conscientious management options for problem individuals range from prohibiting ocean activities (e.g., swimming and surfing) in their habitats to selectively removing the individual, although the latter would be challenging in the marine environment.

Empirical data are essential to assess the outcomes of management decisions in the context of adaptive management. We used flyway-level population indices of a declining game bird to assess population changes after introducing hunting management measures as part of the European Union (EU)-wide Adaptive Harvest Management mechanism (AHMM). In one flyway, a full hunting ban led to the start of population recovery; numbers increased by 25% in 2 years and the 10-year population trend improved from “moderate decline” to “stable.” In the other flyway, harvest was only reduced (allegedly by 60% although statistics from key countries were incomplete), and numbers continued to fall (−15% decline). Our study shows positive results of the leading AHMM for a landbird in Europe and provides empirical evidence of the speed of population response and the timeframe needed for change to occur and to be detected. It showcases the successful application of policy mechanisms underpinned by science.

Lead (Pb) poisoning is a significant threat to Aotearoa New Zealand's endangered kea (Nestor notabilis), an avian species important to Māori. Historically, exposure was thought to be from lead-containing building materials; however, recent field observations suggest lead-based ammunition as an additional source. We used stable lead isotopes to investigate the sources of lead to kea. Comparing ²⁰⁷ Pb/²⁰⁶ Pb ratios in kea blood (n = 91) to both ammunition and building materials, we found approximately one-third of exposed kea (blood lead > 10 µg/dL) had lead isotope ratios consistent with exposure to lead-based ammunition. As lead ammunition is still used, including in government-sponsored culling programs, our data indicate an urgent need to shift toward non-lead ammunition use to prevent further poisoning and aid conservation efforts. Collaborating with tangata whenua/Māori guardians, we advocate for immediate policy changes to eliminate lead-based ammunition in kea habitat to safeguard this endangered culturally treasured species from extinction.

Environmental practitioners often develop communications and behavior change interventions that conceptualize individuals as consumers or as other limited, standalone personae. This view neglects the role of conservation audiences as social beings with complex social relationships and networks, potentially resulting in lost opportunities to increase the effectiveness of conservation interventions. We offer a reframing of individuals as members of social networks who can influence others through their many different societal roles. This framing may help individuals recognize their potential to affect large-scale societal structures and empower them to contribute to systemic changes. In practice, conservation organizations might increase the impact and reach of their behavioral interventions by targeting social referents (individuals or groups who people reference for accepted and desired behaviors) and leveraging interpersonal relationships. This includes encouraging individuals to make use of their networks to discuss issues such as biodiversity loss with a variety of acquaintances to normalize them as a topic of conversation. We argue that organizations can leverage the power of social networks to amplify change and promote the message that people change the world through their social ties, thereby inspiring audiences to further engage in conservation behaviors.

Key Biodiversity Areas (KBAs) are a cornerstone of 21st-century area-based conservation targets. In tropical KBAs, biodiversity is potentially at high risk from climate change, because most species reside within or beneath the canopy, where small increases in temperature can lead to novel climate regimes. We quantify novelty in temperature regimes by modeling hourly temperatures below the forest canopy across tropical KBAs between 1990 and 2019. We find that up to 60% of KBAs with tropical forests have recently transitioned to novel temperature regimes. Nevertheless, 40% of KBAs are providing refuge from novelty, 65% of which are not protected. By conducting the first pan-tropical analyses of changes in below-canopy temperature conditions in KBAs, we identify KBAs that are acting as climate refugia and should be considered for expansion of the conservation network in response to the post-2020 Global Biodiversity Framework target to conserve 30% of land area by 2030.

For centuries, humans have intentionally moved species around the world, and such actions have rarely been laudable from conservation perspectives. The notion that introduced populations of cold-adapted species hold conservation value despite their non-native status remains controversial. Many such populations exist as a legacy of humans moving wildlife to novel environments with little true consideration of species conservation. Herein, we identify cases in which individuals from inadvertent climate refugia (ICR) are returned to formerly occupied ranges or used to augment declining native populations. While conservation benefits have been infrequently realized, the global distribution of ICR offers a potentially untapped resource. Lessening biodiversity loss under increasing climate challenges will likely require assisted migration of many species and necessitate novel valuation of extant introduced populations—such as those within ICR. While ecological costs of translocated species are widely known, we highlight how species moved generations ago to ICR offer a reservoir for reintroductions and a buffer against rapidly changing climates.