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An introduction is presented in which the editor discusses various reports within the issue on topics including the management and preservation of species and the ecosystem, a new approach in freshwater fish conservation and the life trajectory of a jaguar.

In flies, the olfactory information is carried from the first relay in the brain, the antennal lobe, to the mushroom body (MB) and the lateral horn (LH). Olfactory associations are formed in the MB. The LH was ascribed a role in innate responses based on the stereotyped connectivity with the antennal lobe, stereotyped physiological responses to odors, and MB silencing experiments. Direct evidence for the functional role of the LH is still missing. Here, we investigate the behavioral role of the LH neurons (LHNs) directly, using the CO2 response as a paradigm. Our results show the involvement of the LH in innate responses. Specifically, we demonstrate that activity in two sets of neurons is required for the full behavioral response to CO2. Tests of the behavioral response to other odors indicate the neurons are selective to CO2 response. Using calcium imaging, we observe that the two sets of neurons respond to CO2 in a different manner. Using independent manipulation and recording of the two sets of neurons, we find that the one that projects to the superior intermediate protocerebrum (SIP) also outputs to the local neurons within the LH. The design of simultaneous output at the LH and the SIP, an output of the MB, allows for coordination between innate and learned responses. [ABSTRACT FROM AUTHOR]

The physical mechanism of aerial dispersal of spiders, “ballooning behavior,” is still unclear because of the lack of serious scientific observations and experiments. Therefore, as a first step in clarifying the phenomenon, we studied the ballooning behavior of relatively large spiders (heavier than 5 mg) in nature. Additional wind tunnel tests to identify ballooning silks were implemented in the laboratory. From our observation, it seems obvious that spiders actively evaluate the condition of the wind with their front leg (leg I) and wait for the preferable wind condition for their ballooning takeoff. In the wind tunnel tests, as-yet-unknown physical properties of ballooning fibers (length, thickness, and number of fibers) were identified. Large spiders, 16–20 mg Xysticus spp., spun 50–60 nanoscale fibers, with a diameter of 121–323 nm. The length of these threads was 3.22 ± 1.31 m (N = 22). These physical properties of ballooning fibers can explain the ballooning of large spiders with relatively light updrafts, 0.1–0.5 m s−1, which exist in a light breeze of 1.5–3.3 m s−1. Additionally, in line with previous research on turbulence in atmospheric boundary layers and from our wind measurements, it is hypothesized that spiders use the ascending air current for their aerial dispersal, the “ejection” regime, which is induced by hairpin vortices in the atmospheric boundary layer turbulence. This regime is highly correlated with lower wind speeds. This coincides well with the fact that spiders usually balloon when the wind speed is lower than 3 m s−1. [ABSTRACT FROM AUTHOR]

Bigger is apparently frequently fitter, and body size is typically heritable, so why don’t animals in wild populations evolve towards larger sizes? Different explanations have been proposed for this apparent “paradox of stasis.” A new study of snow voles in the Swiss Alps finds higher survival in animals with larger body mass and heritability of body mass, but, surprisingly, a genetic decline in body mass is also indicated. The authors suggest a novel explanation for this observation: the appearance of positive phenotypic selection is driven by a confounding variable of the age at which a juvenile is measured, whereas the evolutionarily relevant selection actually acts negatively on mass via its association with development time. Thus, genes for larger mass are not actually “fitter” because they are associated with longer development times, and juvenile snow voles with longer development times run the risk of not completing development before the first winter snow. However, the genetic decline in body size is not apparent at the phenotypic level, presumably because of countervailing trends in environmental effects on the phenotype. [ABSTRACT FROM AUTHOR]

Current climate change may be a major threat to global biodiversity, but the extent of species loss will depend on the details of how species respond to changing climates. For example, if most species can undergo rapid change in their climatic niches, then extinctions may be limited. Numerous studies have now documented shifts in the geographic ranges of species that were inferred to be related to climate change, especially shifts towards higher mean elevations and latitudes. Many of these studies contain valuable data on extinctions of local populations that have not yet been thoroughly explored. Specifically, overall range shifts can include range contractions at the “warm edges” of species’ ranges (i.e., lower latitudes and elevations), contractions which occur through local extinctions. Here, data on climate-related range shifts were used to test the frequency of local extinctions related to recent climate change. The results show that climate-related local extinctions have already occurred in hundreds of species, including 47% of the 976 species surveyed. This frequency of local extinctions was broadly similar across climatic zones, clades, and habitats but was significantly higher in tropical species than in temperate species (55% versus 39%), in animals than in plants (50% versus 39%), and in freshwater habitats relative to terrestrial and marine habitats (74% versus 46% versus 51%). Overall, these results suggest that local extinctions related to climate change are already widespread, even though levels of climate change so far are modest relative to those predicted in the next 100 years. These extinctions will presumably become much more prevalent as global warming increases further by roughly 2-fold to 5-fold over the coming decades. [ABSTRACT FROM AUTHOR]

Cloud cover can influence numerous important ecological processes, including reproduction, growth, survival, and behavior, yet our assessment of its importance at the appropriate spatial scales has remained remarkably limited. If captured over a large extent yet at sufficiently fine spatial grain, cloud cover dynamics may provide key information for delineating a variety of habitat types and predicting species distributions. Here, we develop new near-global, fine-grain (≈1 km) monthly cloud frequencies from 15 y of twice-daily Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images that expose spatiotemporal cloud cover dynamics of previously undocumented global complexity. We demonstrate that cloud cover varies strongly in its geographic heterogeneity and that the direct, observation-based nature of cloud-derived metrics can improve predictions of habitats, ecosystem, and species distributions with reduced spatial autocorrelation compared to commonly used interpolated climate data. These findings support the fundamental role of remote sensing as an effective lens through which to understand and globally monitor the fine-grain spatial variability of key biodiversity and ecosystem properties. [ABSTRACT FROM AUTHOR]