Surrogate species protection in Bolivia under climate and land cover change scenarios

Gaps and opportunities in modelling human influence on species distributions in the Anthropocene

Understanding species distributions is a global priority for mitigating environmental pressures from human activities. Ample studies have identified key environmental (climate and habitat) predictors and the spatial scales at which they influence species distributions. However, regarding human influence, such understandings are largely lacking. Here, to advance knowledge concerning human influence on species distributions, we systematically reviewed species distribution modelling (SDM) articles and assessed current modelling efforts. We searched 12,854 articles and found only 1,429 articles using human predictors within SDMs. Collectively, these studies of >58,000 species used 2,307 unique human predictors, suggesting that in contrast to environmental predictors, there is no 'rule of thumb' for human predictor selection in SDMs. The number of human predictors used across studies also varied (usually one to four per study). Moreover, nearly half the articles projecting to future climates held human predictors constant over time, risking false optimism about the effects of human activities compared with climate change. Advances in using human predictors in SDMs are paramount for accurately informing and advancing policy, conservation, management and ecology. We show considerable gaps in including human predictors to understand current and future species distributions in the Anthropocene, opening opportunities for new inquiries. We pose 15 questions to advance ecological theory, methods and real-world applications.

Assessing Global Efforts in the Selection of Vertebrates as Umbrella Species for Conservation

The umbrella-species strategy has been proposed as an attainable tool to achieve multi-species and community conservation with limited investment. There have been many umbrella-related studies since the concept's inception; thus, a summary of global study efforts and recommended umbrella species is important for understanding advances in the field and facilitating conservation applications. Here, we collated 213 recommended umbrella species of terrestrial vertebrates from 242 scientific articles published during 1984-2021 and analyzed their geographic patterns, biological features, and conservation statuses to identify global trends in the selection of umbrella species. We found a considerable geographic bias: most studies and, consequently, recommended umbrella species are from the Northern Hemisphere. There is also a strong taxonomic bias, with grouses (order Galliformes) and large carnivores being the most popular umbrella species and amphibians and reptiles being largely overlooked. In addition, wide-ranging and non-threatened species were frequently recommended as umbrella species. Given the observed biases and trends, we caution that appropriate species need to be chosen for each location, and it is important to confirm that popular, wide-ranging species are effective umbrella species. Moreover, amphibians and reptiles should be investigated for their potential as umbrella species. The umbrella-species strategy has many strengths and, if applied appropriately, may be one of the best options in today's conservation research and funding landscape.

Using population surveys and models to reassess the conservation status of an endemic Amazonian titi monkey in a deforestation hotspot

Assessing the conservation status of species is essential for implementing appropriate conservation measures. A lack of evidence of threats, rather than showing an absence of impacts, could reflect a lack of studies on how human activities could result in species population declines. The range of Prince Bernhard's titi monkey Plecturocebus bernhardi is restricted to the Arc of Deforestation, a deforestation hotspot in south-eastern Amazonia. Despite this, it is categorized as Least Concern on the IUCN Red List. To reassess the conservation status of P. bernhardi, we carried out surveys during 2015–2017 to delimit the geographical distribution of the species and estimate its population density and abundance. We then used spatial predictive modelling to examine future habitat and population loss within its range. Plecturocebus bernhardi occurs over an area of 131,295 km2. Its mean group size was 2.8 individuals/group and its density 10.8 individuals/km2 and 3.8 groups/km2. Habitat loss was estimated to be 58,365 km2 (32.3% of its current range) over the next 24 years (three P. bernhardi generations) under a conservative governance model of deforestation and 105,289 km2 (58.3%) under a business-as-usual model. These numbers indicate that P. bernhardi is threatened and should be categorized as Vulnerable, at least, using the IUCN Red List criteria. We recommend the reassessment of other Least Concern primate species from the Arc of Deforestation using a similar approach.

Modelling the distribution of the vector Aedes aegypti in a central Argentine city

Aedes aegypti (Diptera: Culicidae) is an urban mosquito involved in the transmission of numerous viruses, including dengue, chikungunya and Zika. In Argentina, Ae. aegypti is the main vector of dengue virus and has been involved in several outbreaks in regions ranging from northern to central Argentina since 2009. In order to evaluate areas of potential vector-borne disease transmission in the city of Córdoba, Argentina, the present study aimed to identify the environmental, socioeconomic and demographic factors driving the distribution of Ae. aegypti larvae through spatial analysis in the form of species distribution models (SDMs). These models elucidate relationships between known occurrences of a species and environmental data in order to identify areas with suitable habitats for that species and the consequent risk for disease transmission. The maximum entropy species distribution model was able to fit the training data well, with an average area under the receiver operating characteristic curve (AUC) of > 0.8, and produced models with fair extrapolation capacity (average test AUC: > 0.75). Human population density, distance to vegetation and water channels were the main variables predictive of the vector suitability of an area. The results of this work will be used to target surveillance and prevention measures, as well as in mosquito management.