Biodiversity offsets are an increasingly popular yet controversial tool in conservation. Their popularity lies in their potential to meet the objectives of biodiversity conservation and of economic development in tandem; the controversy lies in the need to accept ecological losses in return for uncertain gains. The offsetting approach is being widely adopted, even though its methodologies and the overriding conceptual framework are still under development. This review of biodiversity offsetting evaluates implementation to date and synthesizes outstanding theoretical and practical problems. We begin by outlining the criteria that make biodiversity offsets unique and then explore the suite of conceptual challenges arising from these criteria and indicate potential design solutions. We find that biodiversity offset schemes have been inconsistent in meeting conservation objectives because of the challenge of ensuring full compliance and effective monitoring and because of conceptual flaws in the approach itself. Evidence to support this conclusion comes primarily from developed countries, although offsets are increasingly being implemented in the developing world. We are at a critical stage: biodiversity offsets risk becoming responses to immediate development and conservation needs without an overriding conceptual framework to provide guidance and evaluation criteria. We clarify the meaning of the term biodiversity offset and propose a framework that integrates the consideration of theoretical and practical challenges in the offset process. We also propose a research agenda for specific topics around metrics, baselines and uncertainty.

Shifting baseline syndrome (SBS) is often referred to as a key issue for conservation, yet there is little evidence for its existence. The presence of SBS could influence the validity of participatory monitoring, local ecological knowledge, community based conservation, and conservation education. We outline two forms of SBS: (1) generational amnesia, where knowledge extinction occurs because younger generations are not aware of past biological conditions and (2) personal amnesia, where knowledge extinction occurs as individuals forget their own experience. Two conditions are essential to the identification of SBS: (1) biological change must be present in the system and (2) any perceived changes must be consistent with the biological data. If age or experiencerelated differences in perception are then found, generational amnesia may be occurring. Alternately, if individuals believe current conditions also occurred in the past, personal amnesia may be occurring. Previous studies have not fully addressed these conditions, and hence cannot provide indisputable evidence for the existence of SBS. We present three case studies to examine these issues, which demonstrate both forms of SBS. Shifting baseline syndrome is no longer a cautionary tale, but instead is a real problem for those using human perceptions of change to inform conservation policy-making or management.

In a world of shrinking habitats and increasing competition for natural resources, potentially dangerous predators bring the challenges of coexisting with wildlife sharply into focus. Through interdisciplinary collaboration among authors trained in the humanitiesPalabras Clave: conflicto humano -vida silvestre, depredadores, investigación interdisciplinaria, manejo de la conservación

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 conservation impact. We devised a framework for comprehensively assessing species recovery and conservation success. We propose a definition of a fully recovered species that emphasizes viability, ecological functionality, and representation; and use counterfactual approaches to quantify degree of recovery. This allowed us to calculate a set of 4 conservation metrics that demonstrate impacts of conservation efforts to date (conservation legacy); identify dependence of a species on conservation actions (conservation dependence); quantify expected gains resulting from conservation action in the medium term (conservation gain); and specify requirements to achieve maximum plausible recovery over the long term (recovery potential). These metrics can incentivize the establishment and achievement of ambitious conservation targets. We illustrate their use by applying the framework to a vertebrate, an invertebrate, and a woody and an herbaceous plant. Our approach is a preliminary framework for an International Union for Conservation of Nature (IUCN) Green List of Species, which was mandated by a resolution of IUCN members in 2012. Although there are several challenges in applying our proposed framework to a wide range of species, we believe its further development, implementation, and integration with the IUCN Red List of Threatened Species will help catalyze a positive and ambitious vision for conservation that will drive sustained conservation action.

Finding effective ways of conserving large carnivores is widely recognised as a priority in conservation. However, there is disagreement about the most effective way to do this, with some favouring top-down 'command and control' approaches and others favouring collaboration. Arguments for coercive top-down approaches have been presented elsewhere; here we present arguments for collaboration. In many parts of the developed world, flexibility of approach is built into the legislation, so that conservation objectives are balanced with other legitimate goals. In the developing world, limited resources, poverty and weak governance mean that collaborative approaches are likely to play a particularly important part in carnivore conservation. In general, coercive policies may lead to the deterioration of political legitimacy and potentially to non-compliance issues such as illegal killing, whereas collaborative approaches may lead to psychological ownership, enhanced trust, learning, and better social outcomes. Sustainable hunting/trapping plays a crucial part in the conservation and management of many large carnivores. There are many different models for how to conserve carnivores effectively across the world, research is now required to reduce uncertainty and examine the effectiveness of these approaches in different contexts.

Classifying species by threat status can result in conservation benefits such as increased protection, but can also be an incentive to hunters responding to increased consumer demand for goods perceived to be rare, and therefore valuable. Bioeconomic theory provides a framework for examining the population consequences of differing responses of consumers (demand) and hunters (supply) to perceived rarity. We present a series of illustrative case studies of how perceived rarity affects consumer behavior and hunting pressure, and use a model to explore the scenario of most conservation concern (where rarity itself fuels increased exploitation). Rarity-fuelled demand can have two undesirable outcomes: the species may become trapped at a low population size, or escalating hunting effort may drive the species to extinction. Understanding the response of consumers and hunters to perceived rarity is vital for predicting the impact of intervention strategies that seek to minimize extinction risk.

Summary Applied ecologists often face uncertainty that hinders effective decision-making.Common traps that may catch the unwary are: ignoring uncertainty, acknowledging uncertainty but ploughing on, focussing on trivial uncertainties, believing your models, and unclear objectives.We integrate research insights and examples from a wide range of applied ecological fields to illustrate advances that are generally underused, but could facilitate ecologists’ ability to plan and execute research to support management.Recommended approaches to avoid uncertainty traps are: embracing models, using decision theory, using models more effectively, thinking experimentally, and being realistic about uncertainty.Synthesis and applications. Applied ecologists can become more effective at informing management by using approaches that explicitly take account of uncertainty.

Conservation is particularly difficult to implement for “moving targets”, such as migratory species or landscapes subject to environmental change. Traditional conservation strategies involving static tools (eg protected areas that have fixed spatial boundaries) may be ineffective for managing species whose ranges are changing. This shortfall needs to be addressed urgently. More dynamic conservation‐based approaches have been suggested but remain mostly theoretical, and so implementation issues and measures of success have yet to be explored. In recent years, however, the concept of biodiversity offsets has gained traction in the conservation community. Such offsets effectively replace biodiversity “lost” during current economic development projects, and are intended to ensure “no net loss” of biodiversity overall. Given their flexibility and unique no‐net‐loss requirement, offsets provide a platform for testing dynamic new approaches to conservation. Here we explore the potential for offsets to conserve moving targets, using a complex dynamic example: the migratory saiga antelope (Saiga tatarica) in Uzbekistan.