Should I stay or should I go? Climate change effects on the future of Neotropical savannah bats

AbstractMost extant species are survivors of the last climate change event 20,000 years ago. While past events took place over thousands of years, current climate change is occurring much faster, over a few decades. We modelled the potential distribution area of bat species in the Brazilian Cerrado, a Neotropical savannah, and assessed the potential impacts of climate change up to 2050 in two scenarios. First we evaluated what the impact on the distributions of bat species would be if they were unable to move to areas where climate conditions might be similar to current ones. The novelty of our paper is that, based on least-cost-path analyses, we identified potential corridors that could be managed now to mitigate potential impacts of climate change. Our results indicate that on average, in the future bat species would find similar climate conditions 281 km southeast from current regions. If bat species were not able to move to new suitable areas and were unable to adapt, then 36 species (31.6%) could lose >80% of their current distribution area, and five species will lose more than 98% of their distribution area in the Brazilian Cerrado. In contrast, if bat species are able to reach such areas, then the number of highly impacted species will be reduced to nine, with none of them likely to disappear from the Cerrado. We present measures that could be implemented immediately to mitigate future climate change impacts

Editorial: Human impacts on bats in tropical ecosystems: sustainable actions and alternatives

Globally, the most extraordinary biodiversity is in the tropics, spread in a great diversity of vegetation types and habitats. Among the myriad mammalian groups, bats stand out for their remarkable taxonomic, functional, and phylogenetic diversity (Wilson and Mittermeier, 2019). Within the tropics, bats can be found in different vegetation types varying in a gradient of structural complexity from dense ancient forests to more open landscapes and woodlands in the savannas and fields (Meyer et al., 2004; Carvalho et al., 2021). Bats provide essential ecosystem services such as seed dispersal and pollination of the many plants that have a role in the income of the most impoverished human populations and the formal economy (Lacher et al., 2019). Moreover, as voracious insect predators, bats play a vital role in suppressing agricultural pests, an invaluable service in this part of the world, and disease vectors for humans (Aguiar et al., 2021; Tuneu-Corral et al., 2023). It is widely recognized that the main threat to bats globally is the extensive conversion of natural ecosystems, especially in tropical developing countries (Meyer et al., 2016). This shift in land use results in habitat loss and environmental degradation, with consequent loss of species, ecosystem services, and lineages (Frick et al., 2020; Atagana et al., 2021; Colombo et al., 2023). There is thus an urgent need to disseminate correct information about bats and explore best practices for mitigating the adverse effects stemming from human activities such as vegetation clearing for cattle ranching, agriculture, human settlements, and urbanization. Therefore, in this Research Topic, we aimed to bring together current research that assesses the influence of multiple environmental transformation drivers on the diversity of tropical bats. Nine papers were published in this Research Topic, and they present novel insights into how bats react to human-driven environmental changes and address significant gaps in bat conservation. These studies were conducted by 36 authors in six countries across the American, African and Asian continents (Figure 1). While the sampling was local in seven studies, Brasileiro et al. used data spanning Brazilian biomes, and Xavier et al. carried out a global systematic review. Three key themes emerge from the papers presented in this Research Topic, and we discuss the findings and knowledge gaps related to each theme in the following sections. Figure 1info:eu-repo/semantics/publishedVersio

Carcass persistence and detectability : reducing the uncertainty surrounding wildlife-vehicle collision surveys

Carcass persistence time and detectability are two main sources of uncertainty on roadkill surveys. In this study, we evaluate the influence of these uncertainties on roadkill surveys and estimates. To estimate carcass persistence time, three observers (including the driver) surveyed 114km by car on a monthly basis for two years, searching for wildlife-vehicle collisions (WVC). Each survey consisted of five consecutive days. To estimate carcass detectability, we randomly selected stretches of 500m to be also surveyed on foot by two other observers (total 292 walked stretches, 146 km walked). We expected that body size of the carcass, road type, presence of scavengers and weather conditions to be the main drivers influencing the carcass persistence times, but their relative importance was unknown. We also expected detectability to be highly dependent on body size. Overall, we recorded low median persistence times (one day) and low detectability (<10%) for all vertebrates. The results indicate that body size and landscape cover (as a surrogate of scavengers' presence) are the major drivers of carcass persistence. Detectability was lower for animals with body mass less than 100g when compared to carcass with higher body mass. We estimated that our recorded mortality rates underestimated actual values of mortality by 2±10 fold. Although persistence times were similar to previous studies, the detectability rates here described are very different from previous studies. The results suggest that detectability is the main source of bias across WVC studies. Therefore, more than persistence times, studies should carefully account for differing detectability when comparing WVC studies

Brazilian cave heritage under siege

info:eu-repo/semantics/publishe

Summary of the top Akaike’s Information Criterion models (ΔAICc<2.0) of the mixed Cox proportional hazard function for persistence data with 3-km buffer radius.

<p>All models included site as random effect. LogLik: maximum likelihood value; R²: variance explained by the model; ΔAICc: Akaike’s Information Criterion rank; <i>w</i>: AIC model weights.</p

Estimates of total roadkills corrected for biases introduced by carcass persistence and survey method.

<p>f–detectability (%), s–estimated median carcass persistence time (days), p–probability of a carcass being detected after one day. N'–mortality estimate with correction for detectability and carcass persistence (roadkills/day/km). C’–mortality estimates without correction for detectability and carcass persistence (roadkills/day/km). Confidence intervals are provided when available.</p

Study area with location of monitored roads and protected areas.

<p>Reprinted from Brasilia Environmental Institute (IBRAM) under a CC BY license, with permission from the head of the management of environmental information of IBRAM, original copyright 2016.</p