Protected areas are fundamental to biodiversity conservation, but there is growing recognition of the need to extend beyond protected areas to meet the ecological requirements of species at larger ...scales. Landscape-scale conservation requires an evaluation of management impact on biodiversity under different land-use strategies; this is challenging and there exist few empirical studies. In a conservation landscape in northern Republic of Congo we demonstrate the application of a large-scale monitoring program designed to evaluate the impact of conservation interventions on three globally threatened species: western gorillas, chimpanzees and forest elephants, under three land-use types: integral protection, commercial logging, and community-based natural resource management. We applied distance-sampling methods to examine species abundance across different land-use types under varying degrees of management and human disturbance. We found no clear trends in abundance between land-use types. However, units with interventions designed to reduce poaching and protect habitats--irrespective of land-use type--harboured all three species at consistently higher abundance than a neighbouring logging concession undergoing no wildlife management. We applied Generalized-Additive Models to evaluate a priori predictions of species response to different landscape processes. Our results indicate that, given adequate protection from poaching, elephants and gorillas can profit from herbaceous vegetation in recently logged forests and maintain access to ecologically important resources located outside of protected areas. However, proximity to the single integrally protected area in the landscape maintained an overriding positive influence on elephant abundance, and logging roads--even subject to anti-poaching controls--were exploited by elephant poachers and had a major negative influence on elephant distribution. Chimpanzees show a clear preference for unlogged or more mature forests and human disturbance had a negative influence on chimpanzee abundance, in spite of anti-poaching interventions. We caution against the pitfalls of missing and confounded co-variables in model-based estimation approaches and highlight the importance of spatial scale in the response of different species to landscape processes. We stress the importance of a stratified design-based approach to monitoring species status in response to conservation interventions and advocate a holistic framework for landscape-scale monitoring that includes smaller-scale targeted research and punctual assessment of threats.
Many nations use ecological compensation policies to address negative impacts of development projects and achieve No Net Loss (NNL) of biodiversity and ecosystem services. Yet, failures are widely ...reported. We use spatial simulation models to quantify potential net impacts of alternative compensation policies on biodiversity (indicated by native vegetation) and two ecosystem services (carbon storage, sediment retention) across four case studies (in Australia, Brazil, Indonesia, Mozambique). No policy achieves NNL of biodiversity in any case study. Two factors limit their potential success: the land available for compensation (existing vegetation to protect or cleared land to restore), and expected counterfactual biodiversity losses (unregulated vegetation clearing). Compensation also fails to slow regional biodiversity declines because policies regulate only a subset of sectors, and expanding policy scope requires more land than is available for compensation activities. Avoidance of impacts remains essential in achieving NNL goals, particularly once opportunities for compensation are exhausted.
African forest elephants- taxonomically and functionally unique-are being poached at accelerating rates, but we lack range-wide information on the repercussions. Analysis of the largest survey ...dataset ever assembled for forest elephants (80 foot-surveys; covering 13,000 km; 91,600 person-days of fieldwork) revealed that population size declined by ca. 62% between 2002-2011, and the taxon lost 30% of its geographical range. The population is now less than 10% of its potential size, occupying less than 25% of its potential range. High human population density, hunting intensity, absence of law enforcement, poor governance, and proximity to expanding infrastructure are the strongest predictors of decline. To save the remaining African forest elephants, illegal poaching for ivory and encroachment into core elephant habitat must be stopped. In addition, the international demand for ivory, which fuels illegal trade, must be dramatically reduced.
Loss of habitats or ecosystems arising from development projects (e.g., infrastructure, resource extraction, urban expansion) are frequently addressed through biodiversity offsetting. As currently ...implemented, offsetting typically requires an outcome of “no net loss” of biodiversity, but only relative to a baseline trajectory of biodiversity decline. This type of “relative” no net loss entrenches ongoing biodiversity loss, and is misaligned with biodiversity targets that require “absolute” no net loss or “net gain.” Here, we review the limitations of biodiversity offsetting, and in response, propose a new framework for compensating for biodiversity losses from development in a way that is aligned explicitly with jurisdictional biodiversity targets. In the framework, targets for particular biodiversity features are achieved via one of three pathways: Net Gain, No Net Loss, or (rarely) Managed Net Loss. We outline how to set the type (“Maintenance” or “Improvement”) and amount of ecological compensation that is appropriate for proportionately contributing to the achievement of different targets. This framework advances ecological compensation beyond a reactive, ad‐hoc response, to ensuring alignment between actions addressing residual biodiversity losses and achievement of overarching targets for biodiversity conservation.
Increased recognition of the business case for managing corporate impacts on the environment has helped drive increasingly detailed and quantified corporate environmental goals. Foremost among these ...are goals of no net loss (NNL) and net positive impact (NPI). We assess the scale and growth of such corporate goals. Since the first public, company-wide NNL/NPI goal in 2001, 32 companies have set similar goals, of which 18 specifically include biodiversity. Mining companies have set the most NNL/NPI goals, and the majority of those that include biodiversity, despite the generally lower total global impact of the mining industry on biodiversity compared to the agriculture or forestry industries. This could be linked to the mining industry's greater participation in best practice bodies, high-profile impacts, and higher profit margins per area of impact. The detail and quality of present goals vary widely. We examined specific NNL/NPI goals and assessed the extent to which their key components were likely to increase the effectiveness of these goals in benefiting biodiversity and managing business risk. Nonetheless, outcomes are more important than goals, and we urge conservationists to work with companies to both support and monitor their efforts to achieve increasingly ambitious environmental goals.
Aim: To predict the distribution of suitable environmental conditions (SEC) for eight African great ape taxa for a first time period, the 1990s and then project it to a second time period, the 2000s; ...to assess the relative importance of factors influencing SEC distribution and to estimate rates of SEC loss, isolation and fragmentation over the last two decades. Location: Twenty-two African great ape range countries. Methods: We extracted 15,051 presence localities collected between 1995 and 2010 from 68 different areas surveyed across the African ape range. We combined a maximum entropy algorithm and logistic regression to relate ape presence information to environmental and human impact variables from the 1990s with a resolution of 5 × 5 km across the entire ape range. We then made SEC projections for the 2000s using updated human impact variables. Results: Total SEC area was approximately 2,015,480 and 1,807,653 km 2 in the 1990s and 2000s, respectively. Loss of predicted SEC appeared highest for Cross River gorillas (-59%), followed by eastern gorillas (-52%), western gorillas (-32%), bonobos (-29%), central chimpanzees (-17%) and western chimpanzees (-11%). SEC for Nigeria-Cameroon chimpanzees and eastern chimpanzees was not greatly reduced. Except for Cross River and eastern gorillas, the number of SEC patches did not change significantly, suggesting that SEC loss was caused mainly by patch size reduction. Main conclusions: The first continent-wide perspective of African ape SEC distribution shows dramatic declines in recent years. The model has clear limitations for use at small geographic scales, given the quality of available data and the coarse resolution of predictions. However, at the large scale it has potential for informing international policymaking, mitigation of resource extraction and infrastructure development, as well as for spatial prioritization of conservation effort and evaluating conservation effectiveness.
Hornbills can distinguish between primate alarm calls Rainey, Hugo J.; Zuberbühler, Klaus; Slater, Peter J. B.
Proceedings - Royal Society. Biological sciences/Proceedings - Royal Society. Biological Sciences,
04/2004, Letnik:
271, Številka:
1540
Journal Article
Recenzirano
Odprti dostop
Some mammals distinguish between and respond appropriately to the alarm calls of other mammal and bird species. However, the ability of birds to distinguish between mammal alarm calls has not been ...investigated. Diana monkeys (Cercopithecus diana) produce different alarm calls to two predators: crowned eagles (Stephanoaetus coronatus) and leopards (Panthera pardus). Yellow-casqued hornbills (Ceratogymna elata) are vulnerable to predation by crowned eagles but are not preyed on by leopards and might therefore be expected to respond to the Diana monkey eagle alarm call but not to the leopard alarm call. We compared responses of hornbills to playback of eagle shrieks, leopard growls, Diana monkey eagle alarm calls and Diana monkey leopard alarm calls and found that they distinguished appropriately between the two predator vocalizations as well as between the two Diana monkey alarm calls. We discuss possible mechanisms leading to these responses.
Spatial analysis to inform the mitigation hierarchy Jones, Kendall R.; von Hase, Amrei; Costa, Hugo M. ...
Conservation science and practice,
June 2022, 2022-06-00, 20220601, 2022-06-01, Letnik:
4, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Human activities such as urbanization, infrastructure and agriculture are driving global biodiversity declines. In an attempt to balance economic development goals with biodiversity conservation, ...governments and industry apply a decision‐making framework known as the mitigation hierarchy, with a goal of achieving no net loss or net gain outcomes for biodiversity. Successful application of the mitigation hierarchy requires biodiversity assessments and spatial planning to inform the design of mitigation policies, identify priority areas for biodiversity conservation and impact avoidance, assess the biodiversity impacts of developments, and identify appropriate mitigation measures including offsetting residual impacts. However, guidance on the necessary data and assessment techniques is often lacking, especially in countries where formal mitigation policies do not exist or are in their infancy. Here, we discuss and demonstrate analyses that can help answer some key questions for formulating effective mitigation policies and applying the mitigation hierarchy. We focus on data and analyses that can inform the avoidance and offset steps in particular, and demonstrate these techniques using a case study in Mozambique. While these analyses will not replace field‐based assessments for projects, they offer rapid, low‐cost approaches to support scoping and development of mitigation policy, planning and decision‐making, especially in relatively data‐poor regions.
As part of the Post‐2020 Biodiversity Framework, nations are assessing progress over the past decade in addressing the underlying drivers that influence direct pressures on biodiversity and ...formulating new policies and strategies for the decade to come. For marine conservation, global marine protected area (MPA) coverage is still falling short of the 10% target set in 2010. Here we show that while this reflects a lack of progress in many low‐ and middle‐income countries, a few of these nations have met or exceeded international commitments. To provide an in‐depth explanation of how this was achieved in Gabon, we summarize the lessons learnt by our consortium of policy makers and practitioners who helped implement a comprehensive and ecologically representative network of 20 MPAs. We show the importance of creating a national framework, building long‐term stakeholder support, and focusing on research that guides implementation and policy; and outline a four‐step approach that countries and donors could use as an example to help meet international commitments. By responding to calls to share lessons learned to inform future Convention on Biological Diversity targets, we show how Gabon's experiences could inform change elsewhere.
Numerous protected areas (PAs) have been created in Africa to safeguard wildlife and other natural resources. However, significant threats from anthropogenic activities and decline of wildlife ...populations persist, while conservation efforts in most PAs are still minimal. We assessed the impact level of the most common threats to wildlife within PAs in tropical Africa and the relationship of conservation activities with threat impact level. We collated data on 98 PAs with tropical forest cover from 15 countries across West, Central and East Africa. For this, we assembled information about local threats as well as conservation activities from published and unpublished literature, and questionnaires sent to long-term field workers. We constructed general linear models to test the significance of specific conservation activities in relation to the threat impact level. Subsistence and commercial hunting were identified as the most common direct threats to wildlife and found to be most prevalent in West and Central Africa. Agriculture and logging represented the most common indirect threats, and were most prevalent in West Africa. We found that the long-term presence of conservation activities (such as law enforcement, research and tourism) was associated with lower threat impact levels. Our results highlight deficiencies in the management effectiveness of several PAs across tropical Africa, and conclude that PA management should invest more into conservation activities with long-term duration.
PDF
