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Letter to the Editor [ABSTRACT FROM AUTHOR]

Biodiversity monitoring delivers vital information to those making conservation decisions. Comprehensively measuring terrestrial biodiversity usually requires costly methods that can rarely be deployed at large spatial scales over multiple time periods, limiting conservation efficiency. Here we investigated the capacity of environmental DNA (eDNA) from stream water samples to survey terrestrial mammal diversity at multiple spatial scales within a large catchment. We compared biodiversity information recovered using an eDNA metabarcoding approach with data from a dense camera trap survey, as well as the sampling costs of both methods. Via the sampling of large volumes of water from the two largest streams that drained the study area, eDNA metabarcoding provided information on the presence and detection probabilities of 35 mammal taxa, 25% more than camera traps and for half the cost. While eDNA metabarcoding had limited capacity to detect felid species and provide individual-level demographic information, it is a cost-efficient method for large-scale monitoring of terrestrial mammals that can offer sufficient information to solve many conservation problems. [ABSTRACT FROM AUTHOR]

Factors affecting intraspecific variation in home range size have rarely been examined using modern statistical and remote sensing methods. This is especially true for animals in seasonal savanna environments in Africa, despite this biome's importance for both conservation and development goals. We studied the impacts of spatial and temporal variability in environmental conditions, along with individual and social factors, on home range sizes in African buffalo ( Syncerus caffer) in northeastern Namibia. Our data set spans 4 years, is derived from 32 satellite tracking collars, and contains over 35,000 GPS locations. We used the local convex hull method to estimate home range size from 31 buffalo captured at 6 sites. We used a variety of remotely sensed data to characterize potential anthropogenic and natural boundaries, as well as seasonal and temporal heterogeneity in environmental conditions. Using an information-theoretic, mixed effects approach, our analyses showed that home ranges varied over two orders of magnitude and are among the largest recorded for this species. Variables relating to vegetation and habitat boundaries were more important than abiotic environmental conditions and individual or social factors in explaining variation in home range size. The relative contributions of environmental, individual, social, and linear boundary variables to intraspecific home range size have rarely been examined and prior to this had not been assessed for any species in seasonal savannas of Africa. Understanding the factors that condition space-use patterns of wildlife in this area will lead to better-informed conservation and sustainable development decisions. [ABSTRACT FROM AUTHOR]

Policy action to halt the global loss of biodiversity and ecosystems is hindered by the perception that it would be so costly as to compromise economic development, yet this assumption needs testing. Inspired by the recent Stern Review on the Economics of Climate Change, the leaders of the G8+5 nations commissioned a similar assessment of the economics of losing biodiversity, under the Potsdam Initiative on Biodiversity. Here, we propose a conceptual framework for such a global assessment which emphasizes several critical insights from the environmental economics and valuation literature: contrasting counterfactual scenarios which differ solely in whether they include specific conservation policies; identifying non-overlapping benefits; modeling the production, flow, use and value of benefits in a spatially-explicit way; and incorporating the likely costs as well as possible benefits of policy interventions. Tackling these challenges, we argue, will significantly enhance our ability to quantify how the loss of benefits derived from ecosystems and biodiversity compares with the costs incurred in retaining them. We also summarise a review of the current state of knowledge, in order to assess how quickly this framework could be operationalized for some key ecosystem services. [ABSTRACT FROM AUTHOR]

There exist few quantitative assessments of the relationship between biodiversity per se and economic benefits at scales that are relevant for conservation. Similarly, the merits of Community-Based Natural Resource Management programs for both wildlife and people are contested. Here, we harness two databases, on wildlife surveys and financial benefits, to address these issues for communal conservancies in northwest Namibia. We use ordination methods to characterize the diversity and stability of large wildlife assemblages on conservancies, and demonstrate that diversity (but not stability) is an important explanator of conservancy financial benefits. Our results indicate that for this area of Namibia, biodiversity, as represented by large wildlife assemblages, has an important, positive effect on the tangible financial benefits that people derive from conservation programs. [ABSTRACT FROM AUTHOR]

Traditional ecological knowledge (TEK) can play an important role in the understanding of ecological systems. Although TEK has complemented scientific and managerial programs in a variety of contexts, its formal incorporation into remote sensing exercises has to date been limited. Here, we show that the vegetation classifications of the Ache, an indigenous hunter-gatherer tribe of the Mbaracayu Forest Reserve in Paraguay, are reflected in a supervised classification of satellite imagery of the reserve. Accuracy of classification was toward the low end of the range of published values, but was reasonable given the difficult nature of separating forest classes from satellite images. Comparison of the resultant map with a more traditionally elaborated vegetation map highlights differences between the two approaches and the gain in information obtained by considering TEK classifications. We suggest that integration of TEK and remote sensing may provide alternative insights into the ecology of vegetation communities and land cover, particularly in remote and densely forested areas where ecological field research is often limited by roads and/or trail systems. [ABSTRACT FROM AUTHOR]

Wildlife must adapt to human presence to survive in the Anthropocene, so it is critical to understand species responses to humans in different contexts. We used camera trapping as a lens to view mammal responses to changes in human activity during the COVID-19 pandemic. Across 163 species sampled in 102 projects around the world, changes in the amount and timing of animal activity varied widely. Under higher human activity, mammals were less active in undeveloped areas but unexpectedly more active in developed areas while exhibiting greater nocturnality. Carnivores were most sensitive, showing the strongest decreases in activity and greatest increases in nocturnality. Wildlife managers must consider how habituation and uneven sensitivity across species may cause fundamental differences in human-wildlife interactions along gradients of human influence., (© 2024. The Author(s).)