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Bats represent a major component of forest biodiversity. In forest, bats find many roosting and foraging opportunities. When foraging in forest, different bat species exploit a range of microhabitats according to their echolocation and flight style. When roosting, bats require sufficient numbers of suitable tree cavities. Overall, forest structure may influence both foraging and roosting behaviour, and in turn the number of bat species present and their population size. The exploitation of forests for commercial purposes may be a threat to biodiversity when logging leads to habitat loss, alteration or fragmentation. While some bat species may benefit from an increase in the amount of edge habitat determined by logging, others, more specialized to exploit forest interiors, may be potentially harmed. In this study we set out to assess the effect on foraging bats of different management approaches, comparing locally applied traditional approaches with innovative multifunctional management options and delayed logging. Within the framework of the LIFE+ ManFor C.BD. Project we surveyed the effects of thinning at four Italian forest sites, each representing a separate case study. We found that in logged plots bat activity either showed no difference from unlogged plots or resulted in an increase in foraging activity, suggesting that thinning, at least in the forest types we dealt with, has no adverse consequences on bat foraging. However, in our case the effects varied greatly across sites and were detected mostly when all bat species were pooled together for analysis. We conclude that forest exploitation may be sustainable and even favour foraging bats, but since our work neither covered direct mortality linked with forestry operations nor roost loss, further studies are needed to analyze these important aspects. We also highlight that total bat activity revealed by acoustic surveys carried out with automatic recorders may be used as an appropriate indicator of forestry effects on bats. Download the complete issue.

The Mediterranean Basin is typified by a high degree of species rarity and endemicity that reflects its position, geomorphology, and history. Although the composition and cryptic variation of the bat faunas from the Iberian and Balkan Peninsulas are relatively well studied, data from the Apennine Peninsula are still incomplete. This is a significant shortfall, given the presumed refugial role of this region in the context of Europe's Pleistocene phylogeography. It was thus our aim to supplement the phylogeographical information from the region, generating mitochondrial sequences and reviewing published data, with a focus on the dispersal and diversification patterns characterizing taxa with different life strategies. Site-specific lineages were ascertained, especially in the genera Myotis and Plecotus and amongst the pipistrelloid bats, representing speciose radiations. It was possible to observe disjunct ranges with patches isolated south of the Alps in several species, corresponding with evolution of elevated genetic distance. The genetic subdivision within the continuous Italian range into northern and southern lineages in several taxa indicated the possible past substructure of the refugium. Several shared lineages between the Apennine and Ibero-Maghrebian regions were observed, indicating connectivity between the Adriatic and Atlantic-Mediterranean refuges, and raising questions as to which region these clades originated from and what was the direction of faunal exchange between them. In contrast to Europe's other two main refugia, the Apennine Peninsula is a smaller region with simpler phylogeographical patterns. Nevertheless, our results support the idea that the region generated novel lineages. Whereas diversification in sedentary bats may have been driven through the generation of in situ adaptations, specialization, and niche differentiation, the emergence of species with a tramp strategy could have entailed the utilization of faunal drift and the taxon cycle.

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The barbastelle bat, Barbastella barbastellus (Schreber, 1774) is a medium-sized, tree-dwelling vespertilionid classified as ?Endangered? in Italy; in western Europe it may be one of the rarest bat species. B. barbastellus shows roosting preferences that should be regarded as a key point in conservation protocols. We examined roost selection in a breeding population of B. barbastellus from the Abruzzo Lazio and Molise National Park (central Italy) at three levels: woodland structure and management type; tree characteristics; and cavity characteristics. In 2001-2002, we fitted 31 adult B. barbastellus (29 lactating females, one pregnant female and one male) with 0.48g radio-tags and tracked them to their roost-trees. The bats were tracked for 4.5 ± 3.7 days (range: 0-12 days). We located 33 roosts used by 25 subjects (1.8±1.2 roosts/bat, range 1-5). The bats switched roosts frequently: 13 bats used more than one tree over the study period. A chi-square analysis showed that the roosts were not distributed at random across woodland categories: unmanaged woodland was positively selected, whereas shelterwood-harvested woodland was used in proportion to its availability, and ?pastures+scattered trees? was avoided. Twenty out of 33 roost trees were dead Fagus sylvatica trees; conversely, living F. sylvatica dominated in a tree sample obtained at random; dead trees were used more than expected (Χ² test, P 00.001). Overall, roost trees were significantly taller and had a larger diameter at breast?s height and more cavities than random trees; they also had a lower percent canopy closure than random trees. To highlight which variables were actually associated with selection, we devised a logistic regression model. The full model was significant (P 00.001); removal of tree type and tree height affected the model significantly, but the other variables did not produce detectable effects. The bats roosted under loose bark in 20 of 27 trees, i.e. more frequently than expected (Χ² test, P 0 0.05). B. barbastellus preferred cavities at a greater height (median roost height = 10.1 m, n = 22; median random cavity height = 4.5 m, n = 30; Mann-Whitney test, P 0 0.01). Most roosts faced south (63.6% south facing: 91-270 degrees; 36.4% north facing: 271-90 degrees, n = 22; Χ² test, P 0 0.05). A logistic regression model including cavity type, height above ground and direction faced was significant (P 00.01) and all variables were important for selection. B. barbastellus is probably unable to find suitable roosting sites where intensive and non-selective logging is conducted: areas of ancient woodland should be protected to ensure optimal roosting conditions. In roosting areas, felling operations should be avoided as far as possible; in logged areas, selective timber harvesting protocols preserving dead trees and a significant fraction of mature trees should be adopted. We are indebted to the Nando Peretti Foundation and the Parco Nazionale d?Abruzzo Lazio e Molise for funding our work.

Simple Summary Bioindicators are organisms that react to the quality or characteristics of the environment and their changes. They are vitally important to track environmental alterations and take action to mitigate them. As choosing the right bioindicators has important policy implications, it is crucial to select them to tackle clear goals rather than selling specific organisms as bioindicators for other reasons, such as for improving their public profile and encourage species conservation. Bats are a species-rich mammal group that provide key services such as pest suppression, pollination of plants of economic importance or seed dispersal. Bats show clear reactions to environmental alterations and as such have been proposed as potentially useful bioindicators. Based on the relatively limited number of studies available, bats are likely excellent indicators in habitats such as rivers, forests, and urban sites. However, more testing across broad geographic areas is needed, and establishing research networks is fundamental to reach this goal. Some limitations to using bats as bioindicators exist, such as difficulties in separating cryptic species and identifying bats in flight from their calls. It is often also problematic to establish the environmental factors that influence the distribution and behaviour of bats. Abstract Bats show responses to anthropogenic stressors linked to changes in other ecosystem components such as insects, and as K-selected mammals, exhibit fast population declines. This speciose, widespread mammal group shows an impressive trophic diversity and provides key ecosystem services. For these and other reasons, bats might act as suitable bioindicators in many environmental contexts. However, few studies have explicitly tested this potential, and in some cases, stating that bats are useful bioindicators more closely resembles a slogan to support conservation than a well-grounded piece of scientific evidence. Here, we review the available information and highlight the limitations that arise in using bats as bioindicators. Based on the limited number of studies available, the use of bats as bioindicators is highly promising and warrants further investigation in specific contexts such as river quality, urbanisation, farming practices, forestry, bioaccumulation, and climate change. Whether bats may also serve as surrogate taxa remains a controversial yet highly interesting matter. Some limitations to using bats as bioindicators include taxonomical issues, sampling problems, difficulties in associating responses with specific stressors, and geographically biased or delayed responses. Overall, we urge the scientific community to test bat responses to specific stressors in selected ecosystem types and develop research networks to explore the geographic consistency of such responses. The high cost of sampling equipment (ultrasound detectors) is being greatly reduced by technological advances, and the legal obligation to monitor bat populations already existing in many countries such as those in the EU offers an important opportunity to accomplish two objectives (conservation and bioindication) with one action.

One serious concern associated with the SARS-CoV-2 pandemic is that the virus might spill back from humans to wildlife, which would render some animal species reservoirs of the human virus. We assessed the potential circulation of SARS-CoV-2 caused by reverse infection from humans to bats, by performing bat surveillance from different sites in Central–Southern Italy. We restricted our survey to sampling techniques that are minimally invasive and can therefore be broadly applied by non-medical operators such as bat workers. We collected 240 droppings or saliva from 129 bats and tested them using specific and general primers for SARS-CoV-2 and coronaviruses, respectively. All samples (127 nasal swabs and 113 faecal droppings) were negative for SARS-CoV-2, and these results were confirmed by testing the samples with the Droplet Digital PCR. Additionally, pancoronavirus end-point RT-PCR was performed, and no sample showed specific bands. This outcome is a first step towards a better understanding of the reverse transmission of this virus to bats. Although the occurrence of a reverse zoonotic pattern can only be fully established by serological testing, the latter might represent an in-depth follow-up to a broad-scale preliminary assessment performed with our approach. We encourage the systematic surveillance of bats to help prevent reverse zoonotic episodes that would jeopardize human health, as well as biodiversity conservation and management.

Bats show pronounced and often-adverse reactions to artificial illumination at night (ALAN) when commuting, roosting or foraging. ALAN also affects bat drinking activity, at least when lighting occurs over short intervals. We tested whether continuous illumination of drinking sites over 4-h periods would lead bats to tolerate ALAN and resume drinking in the course of the night. We conducted our experiments in forest (Italy) and desert (Israel) sites to test whether in the latter habitat, where water is scarce, a greater motivation to drink might lead to less adverse bat reactions. We recorded 6853 drinking buzzes and 1647 feeding buzzes from 17 species and one species group. In the forest sites, species that hunt in open spaces or along forest edges showed little (P. pipistrellus and H. savii) or no (P. kuhlii and N. leisleri) drinking activity decrease, while those associated with forest interiors (Barbastella barbastellus, Plecotus auritus and bats in the genus Myotis) exhibited a strong negative response. In the desert sites, all studied species reduced drinking activity, yet in the desert populations of P. kuhlii we recorded stronger adverse reactions only far from human settlements. The harsh reactions that the desert bat species showed towards ALAN rule out any effect of a greater motivation to drink. Illumination had no effect on foraging by most species, except in the forest sites, where Pipistrellus kuhlii and Nyctalus leisleri increased foraging when the light was on, and in the desert sites, where Hypsugo bodenheimeri decreased foraging in such situations. The progressive human encroachment that is taking place in many world regions on both forests and especially deserts, where few sites for drinking are available, may jeopardize bat populations also through increased exposure to ALAN.

Artificial light at night (ALAN) is a pervasive form of pollution largely affecting wildlife, from individual behaviour to community structure and dynamics. As nocturnal mammals, bats are often adversely affected by ALAN, yet some "light-opportunistic" species exploit it by hunting insects swarming near lights. Here we used two potentially competing pipistrelle species as models, Kuhl's (Pipistrellus kuhlii) and common (Pipistrellus pipistrellus) pipistrelles, both known to forage in artificially illuminated areas. We set our study in a mountainous area of central Italy, where only recently did the two species become syntopic. We applied spatial modelling and radiotracking to contrast potential vs. actual environmental preferences by the two pipistrelles. Species distribution models and niche analysis showed a large interspecific niche overlap, including a preference for illuminated areas, presenting a potential competition scenario. Pipistrellus pipistrellus association with ALAN, however, was weakened by adding P.kuhlii as a biotic variable to the model. Radiotracking showed that the two species segregated habitats at a small spatial scale and that P.kuhlii used artificially illuminated sites much more frequently than P.pipistrellus, despite both species potentially being streetlamp foragers. We demonstrate that ALAN influences niche segregation between two potentially competing species, confirming its pervasive effects on species and community dynamics, and provide an example of how light pollution and species' habitat preferences may weave a tapestry of complex ecological interactions.

Bats broadcast rapid sequences of echolocation calls, named 'drinking buzzes', when they approach water to drink on the wing. So far this phenomenon has received little attention. We recorded echolocation sequences of drinking bats for 12 species, for 11 of which we also recorded feeding buzzes. Based on the different sensorial tasks faced by feeding and drinking bats, we hypothesize that the drinking buzz structure will differ from that of feeding buzzes since unlike the latter drinking buzzes are not designed to detect and track mobile prey. We demonstrated that drinking buzzes are structurally different from feeding buzzes. We show that the buzz-II phase common in feeding buzzes is absent in drinking buzzes; that is, call frequency is not lowered to broaden sonar beam since the task of drinking does not imply tracking fast-moving targets. This finding indirectly confirms the role of buzz II in feeding buzzes. Pulse rate in drinking buzzes is also lower than in feeding buzzes, as predicted since the high pulse rate typical of feeding buzzes is important to update rapidly the relative location of moving targets. The most likely function of drinking buzzes is to guide a safe drinking manoeuvre, similar to 'landing buzzes' broadcast when bats land on the ground.

In summer, many temperate bat species use daytime torpor, but breeding females do so less to avoid interferences with reproduction. In forest‐roosting bats, deep tree cavities buffer roost microclimate from abrupt temperature oscillations and facilitate thermoregulation. Forest bats also switch roosts frequently, so thermally suitable cavities may be limiting. We tested how barbastelle bats (Barbastella barbastellus), often roosting beneath flaking bark in snags, may thermoregulate successfully despite the unstable microclimate of their preferred cavities. We assessed thermoregulation patterns of bats roosting in trees in a beech forest of central Italy. Although all bats used torpor, females were more often normothermic. Cavities were poorly insulated, but social thermoregulation probably overcomes this problem. A model incorporating the presence of roost mates and group size explained thermoregulation patterns better than others based, respectively, on the location and structural characteristics of tree roosts and cavities, weather, or sex, reproductive or body condition. Homeothermy was recorded for all subjects, including nonreproductive females: This probably ensures availability of a warm roosting environment for nonvolant juveniles. Homeothermy may also represent a lifesaver for bats roosting beneath loose bark, very exposed to predators, because homeothermic bats may react quickly in case of emergency. We also found that barbastelle bats maintain group cohesion when switching roosts: This may accelerate roost occupation at the end of a night, quickly securing a stable microclimate in the newly occupied cavity. Overall, both thermoregulation and roost‐switching patterns were satisfactorily explained as adaptations to a structurally and thermally labile roosting environment.

Intra-sexual segregation is a form of social segregation widespread among vertebrates. In the bat Myotis daubentonii, males are disproportionately abundant at higher elevations, while females are restricted to lower altitude. Intra-male segregation is also known to occur yet its ecological and behavioural determinants are unclear. We studied male segregation along a river in Central Italy where we tested the following predictions: 1. Upstream ( > 1000 m a.s.l.) males will rely on scarcer prey; 2. To deal with this limitation and exploit a cooler roosting environment, they will employ more prolonged and deeper torpor than downstream (< 900 m a.s.l.) males; 3. Body condition will be better in downstream males as they forage in more productive areas; 4. To cope with less predictable foraging opportunities, upstream males will use more habitat types. Consistent with our predictions, we found that prey were less common at higher altitudes, where bats exhibited prolonged and deeper torpor. Body condition was better in downstream males than in upstream males but not in all summer months. This result reflected a decrease in downstream males’ body condition over the season, perhaps due to the energy costs of reduced opportunities to use torpor and/or intraspecific competition. Downstream males mainly foraged over selected riparian vegetation whereas upstream males used a greater variety of habitats. One controversial issue is whether upstream males are excluded from lower elevations by resident bats. We tested this by translocating 10 upstream males to a downstream roost: eight returned to the high elevation site in 1-2 nights, two persisted at low altitude but did not roost with resident bats. These results are consistent with the idea of segregation due to competition. Living at high altitude allows for more effective heterothermy and may thus be not detrimental for survival, but by staying at lower altitude males increase proximity to females and potentially benefit from summer mating opportunities.