Search

Concern for megafauna is increasing among scientists and non-scientists. Many studies have emphasized that megafauna play prominent ecological roles and provide important ecosystem services to humanity. But, what precisely are megafauna? Here, we critically assess the concept of megafauna and propose a goal-oriented framework for megafaunal research. First, we review definitions of megafauna and analyse associated terminology in the scientific literature. Second, we conduct a survey among ecologists and palaeontologists to assess the species traits used to identify and define megafauna. Our review indicates that definitions are highly dependent on the study ecosystem and research question, and primarily rely on ad hoc size-related criteria. Our survey suggests that body size is crucial, but not necessarily sufficient, for addressing the different applications of the term megafauna. Thus, after discussing the pros and cons of existing definitions, we propose an additional approach by defining two function-oriented megafaunal concepts: keystone megafauna and functional megafauna, with its variant apex megafauna. Assessing megafauna from a functional perspective could challenge the perception that there may not be a unifying definition of megafauna that can be applied to all eco-evolutionary narratives. In addition, using functional definitions of megafauna could be especially conducive to cross-disciplinary understanding and cooperation, improvement of conservation policy and practice, and strengthening of public perception. As megafaunal research advances, we encourage scientists to unambiguously define how they use the term megafauna and to present the logic underpinning their definition.

Over the past few decades, the use of camera‐traps has revolutionized our ability to monitor populations of wild terrestrial mammals. While methods to estimate abundance from individually‐identifiable animals are well‐established, they are mostly restricted to species with clear natural markings or else necessitate invasive and often costly animal tagging campaigns. Estimating abundance or density from unmarked animals remains challenging. Several models recently developed to deal with this issue are promising, but are not widely used by field ecologists. Here, we developed a framework for applying the Space‐To‐Event (STE) model—originally designed to be used with time‐lapse images—on motion‐triggered camera‐trap data. Our approach involves performing bootstrap resampling on the photographic dataset to generate multiple datasets that are then used as input to the STE model. We tested our approach on 29 datasets, including 17 ungulate species from eight sites, in six different countries and various ecosystems. Then, we conducted a regression analysis to evaluate how variations in ecological and sampling conditions across studies affected the bias and precision of our STE density estimates. Our study shows that with a bootstrap resampling approach and information on animal activity and effective detection distances to animals, the STE model can be used to analyze motion‐trigger datasets and provide population density estimates that are similar to those from other methods. We found that measuring the camera viewshed was critical to prevent major negative biases in density estimates. Moreover, using a 1‐s sampling window was important to avoid the positive bias that results from violating the instantaneous‐sampling assumption. We found that precision increased with greater sampling effort and higher density populations. Based on these results, we highlight several issues from past studies that have applied the original timelapse‐based STE to motion‐trigger datasets, issues that our bootstrap resampling approach addresses. We caution that the STE model, whether applied to timelapse or motion‐triggered datasets, relies on strict assumptions. Any violations of these assumptions, such as non‐instantaneous sampling or the application of angle and distance of detection provided by the camera manufacturer, can cause biases in multiple directions that may be difficult to differentiate. [ABSTRACT FROM AUTHOR]

In the pathway toward environmental sustainability, it is important that we understand how individuals can make a difference through diverse types of engagement. Theories suggest that transformative change toward a sustainable future requires individuals to engage in not only private actions (e.g. household energy saving, recycling) but also social‐signalling and system‐changing civic actions (e.g. opinion sharing, voting, petition signing and protesting). Yet, past research on pro‐environmental behaviour has primarily focused on private actions, while overlooking individual contributions to facilitating widespread change through civic actions.We use the exotic pet trade as a focal case to understand how individuals may act to promote environmental sustainability through different patterns of engagement and what factors might explain these distinct patters of action.Results from an online survey about behavioural intentions in the United States (n = 527) revealed three types of individual action that could transform the exotic pet trade.Private actions clustered separately from civic actions. Within the category of civic actions, a distinction emerged between lower social‐commitment actions and higher social‐commitment actions, based on the perceived level of social engagement and personal efforts involved.We also found that each type of action was associated with unique factors, highlighting the importance of attitudes, perceived social norms, and relational values for variously promoting individual engagement among the U.S. public.Our findings suggest that these distinct types of action should be treated differently when designing future wildlife conservation campaigns and behaviour change interventions. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Naidoo works for WWF-US, not WWF-Namibia; the former does not play a role in implementing CBNRM in Namibia. Koot et al. claim we "ignore discordant results", however we cite works by Sullivan in this set of papers 5 times, and those of other authors critical of current community-based and/or "neo-liberal" conservation approaches an additional 10 times. Koot has published highly critical papers on CBNRM in Namibia and elsewhere, and appears to have significant involvement in a community-run lodge in Namibia situated outside of a communal conservancy (Koot [8]). The premise of Koot, Hebinck, and Sullivan ([9]) is that as "professionals working for organizations that have collaboratively instigated and supported CBNRM initiatives" we may be biased toward finding positive outcomes for Namibia's CBNRM program. [Extracted from the article]

The wildlife trade drives biodiversity loss and zoonotic disease emergence, and the health and economic impacts of COVID‐19 have sparked discussions over stricter regulation of the wildlife trade. Yet regulation for conservation and health purposes is at odds with the economic incentives provided by this multibillion‐dollar industry. To understand why the wildlife trade persists despite associated biodiversity and global health threats, we used a benefit–cost approach using simple calculations to compare the economic benefits of the wildlife trade at the individual, national, and global scales to the costs of COVID‐19, severe acute respiratory syndrome (SARS), and Ebola disease across scenarios of epidemic frequency. For COVID‐19, benefits of the wildlife trade outweigh costs at individual scales, but costs far exceed benefits at national and global scales, particularly if epidemics were to become frequent. For SARS and Ebola, benefits outweigh costs at all scales, except if Ebola‐like epidemics were to become frequent. The wildlife trade produces net benefits for people who depend on wildlife for food and income but incurs net costs on stakeholders at larger scales from increased epidemic risk. While our analysis omits a variety of costs and benefits that are difficult to quantify and contrast, our analysis is meant to illustrate the distributional outcomes across stakeholder groups that could result from increased wildlife trade regulation. Importantly, the feasibility of trade regulatory policies will depend on how these benefits and costs compare across groups and would therefore need to involve accessible and attractive alternative sources of food and livelihoods for those who depend on the wildlife trade. [ABSTRACT FROM AUTHOR]