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1.	Ancillotto, Leonardo, et al. (författare) Coastal cliffs on islands as foraging habitat for bats 2014 Ingår i: Acta Chiropterologica. - 1508-1109. ; 16:1, s. 103-108 Tidskriftsartikel (refereegranskat)abstract Small islands usually show simplified ecosystems with limited availability of suitable foraging habitats for bats, thus habitat selection on islands may differ compared to the mainland. Habitats that are marginal on the mainland may be important on islands. The island of Capri consists, to a large extent, of steep limestone cliffs and Mediterranean shrubland, with virtually no forests or other habitats preferred by bats on the mainland. In this study we tested the hypothesis that in resource-limited systems, such as islands, habitats generally deemed of minor value for bat foraging, such as cliffs, may become important. We conducted an acoustic survey of bats in Capri ( SW Italy), comparing their use of Mediterranean shrubland and limestone cliffs. We found that cliffs provided the preferred foraging habitat in four of the five species tested. Noticeably, even the barbastelle bat Barbastella barbastellus, normally considered a forest specialist, selected coastal cliffs as foraging habitat. Our observations indicate that the paucity of foraging habitats on islands may strongly alter the habitat use by bats. This has important implications for conservation of bats in insular environments.
2.	Apoznański, Grzegorz, et al. (författare) Barbastelle bats in a wind farm : are they at risk? 2018 Ingår i: European Journal of Wildlife Research. - : Springer Science and Business Media LLC. - 1612-4642 .- 1439-0574. ; 64:4 Tidskriftsartikel (refereegranskat)abstract We need to know if and how western barbastelles Barbastella barbastellus are affected by wind farming in Sweden. This is because wind turbines are frequently constructed in barbastelle habitats and yet there is no national guideline on how the arising conflict should be handled. We studied the movement, behavior and mortality of a barbastelle population at a wind farm in southern Sweden, using radio-telemetry, automatic bat detectors and carcass searches. The tagged bats (6 males and 8 females) roosted mainly under loose bark of dead oak trees and foraged in patches of mature deciduous woodlands or pockets of mature spruce trees within 15 km of the roosts. Extensive areas of young spruce plantation, open farmland and lakes were not used for roosting or foraging but were crossed by commuting bats. Continuous recordings with bat detectors frequently picked up barbastelles at forest edges 30 m from the turbines, but rarely over the turbine pads within 10 m from the turbines and never at heights of 30 and 100 m at the turbine towers. Barbastelles were apparently not attracted to the wind turbines and did not seem to interact with them in any way. Carcass searches under 10 wind turbines at 1-week intervals over three summers did not reveal any dead barbastelles, although three other species were recovered. We conclude that wind farming is not nessarily incompatible with effective conservation of barbastelles in Sweden, but instead of focusing on wind turbines, effors should concentrate on (a) preservation and restoration of mature, age-structured deciduous woodlands and spruce forests, including very small and isolated patches, which provide food and roosts, and probably also (b) avoidance of outdoor lighting in areas used by barbastelles. Designating large circular buffer zones around each known or suspected colony according to current practice would be inefficient or meaningless in our case, because barbastelles use extensive home ranges and switch roost frequently. We argue that barbastelle management must be applied on a landscape scale.
3.	Apoznański, Grzegorz, et al. (författare) Barbastelles in a Production Landscape : Where Do They Roost? 2021 Ingår i: Acta Chiropterologica. - 1508-1109. ; 23:1, s. 225-232 Tidskriftsartikel (refereegranskat)abstract Extensive areas of old forests have declined all over the temperate regions of Europe mainly due to extensive forestry. This is likely to have negative impact on bats that roost in trees, such as the western barbastelle Barbastella barbastellus. We investigated its selection of summer roosts in a commercially used landscape in southern Sweden. We captured and radio-tracked 14 bats and found 17 occupied roosts. Nine of the roosts, including two used by a maternity colony (ca. 30 females), were located between overlapping boards on the gables of barns. The remaining eight roosts, all used by single individuals, were under lose bark on thin trees (DBH = 0.2-0.35 m). All recorded roosts had entrances pointing downwards, were adjacent to deciduous trees providing protective darkness, and were in areas without artificial lighting. In the barns, the bats avoided the northern aspect, which is the lightest (sun sets in the NW and rises in the NE). Roost temperatures did not differ between tree-and barn roosts. Average ambient light intensity on emergence and return was 13.3 lux (SD = 10.1 lux). Roosts in trees and barns shared common physical characteristics, yet despite this both maternity roosts were located in barns, perhaps because such roosts had more space than available tree roosts. Our results suggest that in areas deprived of large trees and extensive old forest, barbastelle shows flexibility in roost selection, although they consistently avoid artificial lights of all kinds. An abundance of potential roosts in trees and buildings and absence of light pollution are therefore key elements in a holistic conservation program for this species.
4.	Arnett, Edward B., et al. (författare) Impacts of wind energy development on bats : A global perspective 2015 Ingår i: Bats in the Anthropocene: Conservation of Bats in a Changing World. - Cham : Springer International Publishing. - 9783319252186 - 9783319252209 ; , s. 295-323 Bokkapitel (refereegranskat)abstract Wind energy continues to be one of the fastest growing renewable energy sources under development, and while representing a clean energy source, it is not environmentally neutral. Large numbers of bats are being killed at utility-scale wind energy facilities worldwide, raising concern about cumulative impacts of wind energy development on bat populations. We discuss our current state of knowledge on patterns of bat fatalities at wind facilities, estimates of fatalities, mitigation efforts, and policy and conservation implications. Given the magnitude and extent of fatalities of bats worldwide, the conservation implications of understanding and mitigating bat fatalities at wind energy facilities are critically important and should be proactive and based on science rather than being reactive and arbitrary.
5.	Brydegaard, Mikkel, et al. (författare) High Dynamic Range in Entomological Scheimpflug Lidars 2021 Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - 1077-260X. ; 27:4 Tidskriftsartikel (refereegranskat)abstract Minimizing insecticide use, preventing vector diseases and facilitating biodiversity assessments are suitable applications of recent advances in photonic insect surveillance and entomological lidar. The tools also comprise a new window into fundamental aspect of the fascinating life and ecology of insects and their predators in situ. At the same time, it is evident that lidars are subject to finite detection range given by the instrument noise and saturation levels, and therefore, intervals of the biomass spectra are sectioned at different ranges. The Scheimpflug lidar allows an interesting trade-off between high sample rate and low pulse energy for retrieving wing beat harmonics and slow sample rates with high pulse energy for detecting small species far away. In this paper, we review and revise calibration, sizing and associated deficiencies, and report count rates to 104 insects/minute up to 2 km range. We investigate if and how high dynamic range can be exploited in entomological lidar and also how fast and slow sample rates could complement each other and capture a wider span of the biomass spectrum. We demonstrate that smaller insect can be detected further away by long exposures and show consistency between the captured biomass size spectra. However, we find unexpected discrepancies between short and long exposures in the range distributions. We found that vertebrates as well as specular insects can saturate signals. Error sources and limitations are elaborated on.
6.	Chou, Cheng Han, et al. (författare) Bat fatalities at wind farms in Taiwan 2017 Ingår i: Mammal Study. - : Mammalogical Society of Japan. - 1343-4152 .- 1348-6160. ; 42:2, s. 121-124 Tidskriftsartikel (refereegranskat)abstract We collected bat carcasses at three wind farms in Taiwan, located along the west coast mostly near the sea and/or in former coastal wetland habitats. We found 43 bat carcasses, mostly of common aerial-hawking species such as Pipistrellus abramus and Scotophilus kuhlii, but the island endemics Eptesicus serotinus horikawai and Myotis formosus flavus were also recovered. All bat species affected are believed to remain on the island all year. As far as we know this is the first report of bat fatalities at wind energy facilities in eastern Asia.
7.	Eklöf, Johan, et al. (författare) Attitudes towards Bats in Swedish History 2021 Ingår i: Journal of Ethnobiology. - : Society of Ethnobiology. - 0278-0771. ; 41:1, s. 35-52 Tidskriftsartikel (refereegranskat)abstract Bats have always fascinated people by their unusual appearance, but fear towards them is also common, particularly in Western societies. Making headlines worldwide during the recent COVID-19 pandemic, bats were all too often accused of carrying and transmitting a disproportionate share of dangerous viruses. We enquired about the origin and persistence of this thinking in Sweden by searching old literature and original museum records where bats are mentioned. In the Bible, the bat is an explicitly unclean animal. At least since the Middle Ages, it has been used as a symbol of the Devil, with the dark skin wings in deliberate contrast to the white wings of angels. However, according to our folklore records, the bat was usually seen in a different and generally positive context by the people, and was treated with respect. Its magic properties, particularly contained in the blood, eyes, and wings, could bring fortune and prevent bad luck in various everyday contexts. A minority of records refer to bats being used in witchcraft, black magic, or, following the religious dogma, claiming that they are ugly or unclean and cannot be the work of God. We found no indication that bats were considered aggressive, dangerous, or to carry disease. Hence, we surmise there was little fear of bats in Swedish (Nordic) history, despite the religious message. Hence, the general attitude towards bats in the past seems to have been opposite to the view currently met in Western societies.
8.	Jansson, Samuel, et al. (författare) A Scheimpflug lidar used to observe insect swarming at a wind turbine 2020 Ingår i: Ecological Indicators. - : Elsevier BV. - 1470-160X. ; 117 Tidskriftsartikel (refereegranskat)abstract Wind turbines have considerable impact on flying animals, particularly bats, which are sometimes killed in large numbers by the moving rotors. A longstanding question remains why bats are attracted to wind turbines and risk their lives among the moving rotor blades. One hypothesis is that they feed on insects swarming around the turbine towers and another is that they congregate there to court. The two are not mutually exclusive and may occur more or less simultaneously. It has been difficult to distinguish these hypothesis, because techniques that permit observations of small insects over the relevant distances (~100 m) in the dark are lacking. In this study, we monitored insects at the top of a wind turbine using a novel high-resolution Scheimpflug lidar. The instrument was employed around dusk during ten late summer nights in 2018, with the principal aim to evaluate its performance under real field conditions. Insect swarms were observed near the top of the turbine tower on every night. They appeared in short intervals and varied in density, timing, exact location and size of the swarming insects from day to day. Swarms formed in the afternoon and either dispersed around sunset before the emergence of bats, or remained until darkness, when bats arrived at the turbine. Some of the bats fed there, as indicated by ultrasonic feeding-buzzes, and also engaged in social interactions possibly including courtship, as indicated by song-flights. Daily variation in the formation, dispersal and behavior of the insect swarms appeared to be influenced by temperature and wind speed and also differed among the insect species.
9.	Malmqvist, Elin, et al. (författare) The bat–bird–bug battle : Daily flight activity of insects and their predators over a rice field revealed by high-resolution scheimpflug lidar 2018 Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 5:4 Tidskriftsartikel (refereegranskat)abstract We present the results of, to our knowledge, the first Lidar study applied to continuous and simultaneous monitoring of aerial insects, bats and birds. It illustrates how common patterns of flight activity, e.g. insect swarming around twilight, depend on predation risk and other constraints acting on the faunal components. Flight activity was monitored over a rice field in China during one week in July 2016, using a high-resolution Scheimpflug Lidar system. The monitored Lidar transect was about 520 m long and covered approximately 2.5 m3. The observed biomass spectrum was bimodal, and targets were separated into insects and vertebrates in a categorization supported by visual observations. Peak flight activity occurred at dusk and dawn, with a 37 min time difference between the bat and insect peaks. Hence, bats started to feed in declining insect activity after dusk and stopped before the rise in activity before dawn. A similar time difference between insects and birds may have occurred, but it was not obvious, perhaps because birds were relatively scarce. Our observations are consistent with the hypothesis that flight activity of bats is constrained by predation in bright light, and that crepuscular insects exploit this constraint by swarming near to sunset/sunrise to minimize predation from bats.
10.	Michaelsen, Tore Christian, et al. (författare) Uncertainty and ignored information in the analysis of bat ultrasound : Bayesian approximation to the rescue 2022 Ingår i: Ecological Informatics. - : Elsevier BV. - 1574-9541. ; 70 Tidskriftsartikel (refereegranskat)abstract Bat ultrasound analysis has been around for several decades and it is one of the most important tools in studies of bat ecology. Discrimination between species is based on intra-specific features of echolocation calls. Identification of species and genera in audio files can be attempted either manually or through software which performs a fully automated discrimination between species. However, significant overlap in various features (e.g. frequencies of calls) exists between species and even genera. Species ID is therefore often not an absolute conclusion, but rather an opinion or best guess, as opposed to DNA tests or measurements on external characters of captured bats. To make things even worse, the probability of actually observing a bat of a given species in space and time is ignored when performing bat ultrasound analysis. This study introduces Bayesian approximation through a new method we have named Alternative Bayesian Bat Analysis (ABBA). We show, through a simple proof-of-concept example, the importance of adding information about the local composition of the bat community, hence making informed decisions regarding which species is most likely present in audio files. The superior performance of ABBA is also shown through an example using R code. Here, we use simulated data for three Pipistrellus spp., a genus with significant overlap in frequencies, but the code can easily be adapted to other bat species and genera worldwide. ABBA outperformed the non-Bayesian approach for all three species. The rare species in the simulated data set was super-inflated when using the non-Bayesian method. Further the results show, contrarily to common belief, that the frequency dominated by a given species in a data set, depends on the composition of the bat fauna and not just means and SDs reported in the literature. ABBA allows researchers to include all observations in statistical modeling, rather than excluding observations, an approach which can affect the reliability of studies. This study also, to a great extent, explains the poor performance of software attempting automated bat ID. Implementing Bayesian algorithms, and thereby allowing users to interact with the software, should significantly improve their performance.
11.	Musila, Simon, et al. (författare) No lunar phobia in insectivorous bats in Kenya 2019 Ingår i: Mammalian Biology. - : Springer Science and Business Media LLC. - 1616-5047. ; 95, s. 77-84 Tidskriftsartikel (refereegranskat)abstract We monitored foraging insectivorous bats along walked transects in forest and farmland at Arabuko-Sokoke Forest in coastal Kenya, using a heterodyne bat detector. The main purpose was to test whether aerial-hawking insectivorous bats that feed in open places (in this case mostly Scotophilus and Scotoecus spp.) show lunar phobia, i.e. restricting their activity on moonlit nights. Such behavior would be an expected response to the threat posed by visually oriented aerial predators such as bat hawks, owls and carnivorous bats. The occurrence of lunar phobia in bats is a controversial issue and may have implications for how bats will be affected by increasing light pollution. Our results show that foraging activity of the bats that we studied was related to time of day, season, and habitat, albeit with no additional effect of moonlight discernable. We therefore conclude that foraging activity occurs independently of moonlight. This result is partly at odds with previous findings including predictions from a meta-analysis of lunar phobia in bats, which indicates that lunar phobia is common in these animals, though most likely to be present in tropical species that feed in open situations near vegetation and over water. Equally, our results conform to findings from studies of aerial insectivorous bats in tropical as well as temperate areas, most of which have failed to reveal any clear evidence of lunar phobia. We believe that moonlight generally does not facilitate aerial predation on flying bats in open situations, or, alternatively, the bats accept increased predation pressure while they fulfil the energetic requirements through hunting.
12.	Rydell, Jens, et al. (författare) Age of enlightenment : Long-term effects of outdoor aesthetic lights on bats in churches 2017 Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 4:8 Tidskriftsartikel (refereegranskat)abstract We surveyed 110 country churches in south-western Sweden for presence of brown long-eared bats Plecotus auritus in summer 2016 by visual inspection and/or evening emergence counts. Each church was also classified according to the presence and amount of aesthetic directional lights (flood-lights) aimed on its walls and tower from the outside. Sixty-one of the churches had previously been surveyed by one of us (J.R.) between 1980 and 1990, before lights were installed on Swedish churches, using the same methods. Churches with bat colonies had decreased significantly in frequency from 61% in 1980s to 38% by 2016. All abandoned churches had been fitted with flood-lights in the period between the two surveys. The loss of bat colonies from lit churches was highly significant and most obvious when lights were applied from all directions, leaving no dark corridor for the bats to leave and return to the roost. In contrast, in churches that were not lit, all of 13 bat colonies remained after 25+ years between the surveys. Lighting of churches and other historical buildings is a serious threat to the long-term survival and reproduction of light-averse bats such as Plecotus spp. and other slow-flying species. Bat roosts are strictly protected according to the EU Habitats Directive and the EUROBATS agreement. Lighting of buildings for aesthetic purposes is becoming a serious environmental issue, because important bat roosts are destroyed in large numbers, and the problem should be handled accordingly. As a start, installation of flood-lights on historical buildings should at least require an environmental impact assessment (EIA).
13.	Rydell, Jens, et al. (författare) Bat Activity at a Small Wind Turbine in the Baltic Sea 2015 Ingår i: Acta Chiropterologica. - 1508-1109. ; 17:2, s. 359-364 Tidskriftsartikel (refereegranskat)abstract Activity of bats at an old wind park four km off the island of Gotland in the Baltic Sea was monitored during 50 nights from August to October 2013, using an automatic bat detector (Pettersson D500-X) mounted on one of the turbines. Single individuals or pairs of common noctules Nyctalus noctula were recorded on five occasions only (26 and 27 August), all in calm weather and when little or no rotor movement occurred. Since such conditions were unusual (five of 50 nights of observation) the visits by the bats were unlikely to be chance events (migrating bats passing the turbine), but more likely involved bats attracted to the turbines. However, no feeding buzzes were recorded and the bats never stayed near the turbine more than one minute. The turbines studied are lit by 250 W white lights and this could have been the reason why bats visited the turbines, because such lights potentially attract insects. The bats could not have been attracted to the turbines by any factor related of the movement of the rotor or the generator, such as Doppler-effects, noise, heat or electric fields.
14.	Rydell, Jens, et al. (författare) Bat mortality at wind turbines in northwestern Europe 2010 Ingår i: Acta Chiropterologica. - 1508-1109. ; 12:2, s. 261-274 Tidskriftsartikel (refereegranskat)abstract We reviewed published and unpublished written reports on bat mortality at wind farms in northwestern Europe. The estimated number of bats killed per turbine annually was relatively low (0-3) on flat, open farmland away from the coast, higher (2-5) in more complex agricultural landscapes, and highest (5-20) at the coast and on forested hills and ridges. The species killed almost exclusively (98%) belonged to a group (Nyctalus, Pipistrellus, Vespertilio and Eptesicus spp.) adapted for open-air foraging. The bats were killed by the moving rotor blades as they hunted insects attracted to the turbines. This occurred independently of sex and age. Peak mortality varied considerably in frequency and timing among years, but the events usually (90%) occurred on nights with low wind speeds in late July to early October and to a lesser extent (10%) also in April-June. The mortality increased with turbine tower height and rotor diameter but was independent of the distance from the ground to the lowest rotor point. It was also independent of the size of the wind park (1-18 turbines). Bat species other than the open-air suite referred to above are usually not at risk at wind turbines, because they fly below the rotors, but are still killed occasionally (2%).
15.	Rydell, Jens, et al. (författare) Bat selfies : photographic surveys of flying bats 2022 Ingår i: Mammalian Biology. - : Springer Science and Business Media LLC. - 1616-5047 .- 1618-1476. ; 102:3, s. 793-809 Tidskriftsartikel (refereegranskat)abstract The recent pandemic and other environmental concerns have resulted in restrictions on research and surveys involving capture and handling bats. While acoustic surveys have been widely used as an alternative survey method, in this study, we show how photographic surveys can offer an important contribution to study and survey bats. We outline approaches, using high speed flash and automated trip beams to obtain photos of flying bats of sufficient quality for reliable identification of species. We show, through a series of examples of setups and photographs, that photography is effective for surveying bats at a variety of sites, where bats roost, drink, and forage. We note, however, that photographic surveys cannot replace capture in all situations. In addition, although photographing bats is less invasive than capturing them, it can involve disturbance, so we stress the importance of minimizing the impact of such operations on bats.
16.	Rydell, Jens, et al. (författare) Bats may eat diurnal flies that rest on wind turbines 2016 Ingår i: Mammalian Biology. - : Springer Science and Business Media LLC. - 1616-5047. ; 81:3, s. 331-339 Tidskriftsartikel (refereegranskat)abstract Bats are currently killed in large numbers at wind turbines worldwide, but the ultimate reason why this happens remains poorly understood. One hypothesis is that bats visit wind turbines to feed on insects exposed at the turbine towers. We used single molecule next generation DNA sequencing to identify stomach contents of 18 bats of four species (Pipistrellus pygmaeus, Nyctalus noctula, Eptesicus nilssonii and Vespertilio murinus) found dead under wind turbines in southern Sweden. Stomach contents were diverse but included typically diurnal flies, e.g. blow-flies (Calliphoridae), flesh-flies (Sarcophagidae) and houseflies (Muscidae) and also several flightless taxa. Such prey items were eaten by all bat species and at all wind turbine localities and it seems possible that they had been captured at or near the surface of the turbines at night. Using sticky traps, we documented an abundance of swarming (diurnal) ants (Myrmica spp.) and sometimes blow-flies and houseflies at the nacelle house. Near the base of the tower the catches were more diverse and corresponded better with the taxa found in the bat stomachs, including various diurnal flies. To evaluate if flies and other insects resting on the surface of a wind turbine are available to bats, we ensonified a house fly (Musca) on a smooth (plastic) surface with synthetic ultrasonic pulses of the frequencies used by the bat species that we had sampled. The experiment revealed potentially useful echoes, provided the attack angle was low and the frequency high (50-75 kHz). Hence resting flies and other arthropods can probably be detected by echolocating bats on the surface of a wind turbine. Our findings are consistent with published observations of the behavior of bats at wind turbines and may actually explain the function of some of these behaviors.
17.	Rydell, Jens, et al. (författare) Dramatic decline of northern bat Eptesicus nilssonii in Sweden over 30 years 2020 Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 7:2 Tidskriftsartikel (refereegranskat)abstract We monitored northern bat Eptesicus nilssonii (Keyserling & Blasius, 1839) acoustically along a 27 km road transect at weekly intervals in 1988, 1989 and 1990, and again in 2016 and 2017. The methodology of data collection and the transect were the same throughout, except that the insect-attracting mercury-vapour street-lights along parts of the road were replaced by sodium lights between the two survey periods. Counts along sections of the transect with and without streetlights were analysed separately. The frequency of bat encounters in unlit sections showed an average decline of 3.0% per year, corresponding to a reduction of 59% between 1988 and 2017. Sections with street-lights showed an 85% decline over the same period (6.3% per year). The decline represents a real reduction in the abundance of bats rather than an artefact of changed distribution of bats away from roads. Our study conforms with another long-term survey of the same species on the Baltic island of Gotland. Our results agree with predictions based on climate change models. They also indicate that the decline was caused directly by the disuse of the insect-attracting mercury-vapour street-lights, which may have resulted in lower availability of preferred prey (moths). In the 1980s, E. nilssonii was considered the most common bat in Sweden, but the subsequent decline would rather qualify it for vulnerable or endangered status in the national Red List of Threatened Species.
18.	Rydell, Jens, et al. (författare) How to leave the church : light avoidance by brown long-eared bats 2021 Ingår i: Mammalian Biology. - : Springer Science and Business Media LLC. - 1616-5047 .- 1618-1476. ; 101:6, s. 979-986 Tidskriftsartikel (refereegranskat)abstract Light pollution, light in the wrong place at the wrong time, is an emerging environmental issue with wide-ranging consequences. It interferes with the fundamental 24 h light–dark cycle, and has biological effects at all levels, from molecules to ecosystems, including human health and welfare. Here, exemplified by flood-lit churches, artificial lights compromise the survival of resident bats, as darkness provides protection from predation. We predicted that brown long-eared bats Plecotus auritus emerging from churches should (1) avoid illuminated church walls, and (2) avoid extended flights in the open. To test these predictions, bats were observed emerging from 33 country churches in Sweden. A model for light intensity at increasing distances from light sources was made. This model, in combination with known distance between church walls and surrounding lamps, was used to predict lux levels (lx) at each church wall. Higher light intensities were strictly avoided and the majority of bats emerged when light intensities at church walls were below 1.25 lx. Further, most brown long-eared bats flew into the canopy of trees less than 15 m distant from the churches. Bats and their roosts are strictly protected in Europe, but this is poorly enforced with respect to churches and other historical buildings. Nevertheless, lighting of buildings is a key issue in bat conservation and of worldwide significance. We strongly advise that installation of lights near historical buildings is regulated and subject to environmental impact assessments.
19.	Rydell, Jens, et al. (författare) Long-Term Increase in Hibernating Bats in Swedish Mines - Effect of Global Warming? 2018 Ingår i: Acta Chiropterologica. - 1508-1109. ; 20:2, s. 421-426 Tidskriftsartikel (refereegranskat)abstract We present the result of bat winter censuses in three old mines in southern Sweden from 1980 until present (2017). The Taberg and Kleva mines, each with about 1.5 km of accessible passages, have winter populations of 517 and 132 bats, respectively (maximum counts) belonging to six species, the highest numbers known in underground sites in Sweden. Ädelfors is less extensive and has fewer individuals (maximum 22). The two former sites were protected and gated in the 1980′s while the third site still has no formal protection and is subject to disturbance. Generally Daubenton's bat Myotis daubentonii and the brown long-eared bat Plecotus auritus are common species and the numbers are stable. The whiskered and Brandt's bats M. mystacinus/brandtii and Natterer's bat M. nattereri have increased significantly, while the northern bat Eptesicus nilssonii, which is relatively rare in mines generally, has shown a slight but significant decline. At the species level the population trends conform well to those of the respective species in continental Europe and the British Isles. This suggests that there is a common factor behind the population changes across Europe. Although our data are very limited, the results question some previous explanations for the observed trends, but are in line with theoretical predictions based on global warming scenarios.
20.	Rydell, Jens, et al. (författare) Mortality of bats at wind turbines links to nocturnal insect migration? 2010 Ingår i: European Journal of Wildlife Research. - : Springer Science and Business Media LLC. - 1612-4642 .- 1439-0574. ; 56:6, s. 823-827 Forskningsöversikt (refereegranskat)abstract This note is based on a literature search and a recent review of bat mortality data from wind farms in Europe (published elsewhere). We suggest that mortality of bats at wind turbines may be linked to high-altitude feeding on migrating insects that accumulate at the turbine towers. Modern wind turbines seem to reach high enough into the airspace to interfere with the migratory movements of insects. The hypothesis is consistent with recent observations of bats at wind turbines. It is supported by the observation that mortality of bats at wind turbines is highly seasonal (August-September) and typically peaks during nights with weather conditions known to trigger large-scale migratory movements of insects (and songbirds). We also discuss other current hypotheses concerning the mortality of bats at wind turbines.
21.	Rydell, Jens, et al. (författare) Nordfladdermus och barbastell : Hänsyn vid etablering och drift av vindkraftverk 2018 Rapport (övrigt vetenskapligt/konstnärligt)abstract A) Allmänt. Avsikten med det här projektet var att belysa specifika kunskapsluckor som för närvarande utgör potentiella problem eller hinder vid utbyggnad och drift av vindkraftverk i Sverige, brister som identifierats i den första syntesrapporten i ämnet som publicerades 2011 och även i den uppdaterade rapporten från 2017. Det gäller om och hur två av våra fladdermusarter nämligen nordfladdermus Eptesicus nilssonii och barbastell Barbastella barbastellus, påverkas av vindkraft och i så fall hur vi bör hantera detta. Den förra är särskilt viktig i norr, där den ofta är den enda förekommande fladdermusarten i områden med vindkraft, medan den senare, som förekommer i södra Sverige, anses kräva särskilda försiktighetsåtgärder vid etablering och drift av vindkraftverk.B) Nordfladdermus. Vi mätte aktivitet av fladdermöss i marknivå och från navhöjd vid tre vindparker i norra Sverige (Dalarna, Västernorrland och Västerbotten) kontinuerligt från slutet av juni till slutet av oktober 2017 med hjälp av automatiska ultraljudsdetektorer. Aktiviteten av fladdermöss var koncentrerad till vissa nätter under sensommaren (slutet av juli till början av september), men den var sporadisk och nästan helt begränsad till marknivån. Endast en inspelning gjordes med mikrofonen placerad i navhöjd. Förutom nordfladdermus förekom även tajga/mustaschfladdermus Myotis brandtii/ mystacinus vid de undersökta vindkraftverken, men den påträffades inte i rotorhöjd. Med utgångspunkt från detta material, som ännu är begränsat, anser vi att förekomst av fladdermöss rimligtvis inte bör utgöra något hinder för drift av vindkraftverk i höjdlägen i norra Sveriges inland. Naturvårdsinsatser bör istället koncentreras på att skydda skog med naturskogsliknande kvalitéer från skogsbruk.C) Barbastell. Vi undersökte en barbastellpopulation i centrala Halland med hjälp av radiospårning, automatiska ultraljudsdetektorer och eftersök av kadaver under 2016–2017, med avsikt att belysa denna specifika arts val av jaktmiljö och boplatser samt dess beteende och olycksfrekvens vid befintliga vindkraftverk. Radiospårning och aktivitetsmätning med ultraljudsdetektor från marken och från kraftverkstorn visar att barbastellerna ignorerade kraftverken inklusive omgivande grusplaner och annan infrastruktur. Inga vindkraftsdödade barbasteller hittades. Boplatser fanns bakom lös bark på döda eller döende träd eller under ytterpanelen på lador. Barbastellerna jagade nästan uteslutande i rester av artrik skog med naturskogsliknande kvalitéer, mestadels i lövskog men ibland i granskog, på branta eller steniga sluttningar, i våtmarker samt på åkerholmar, det vill säga där skogen fått stå kvar under lång tid och kunnat utvecklas fritt. De utnyttjade små och isolerade skogsrester upp till 15 km eller mer från boplatsen. Den odlade granskogen, som nu utgör ca 90 % av vindparken, samt öppen åkermark och sjöar, användes inte i någon större utsträckning för annat än transport. Vår slutsats är att vindkraften inte har någon nämnvärd direkt påverkan på barbastellen men däremot en indirekt sådan, eftersom gammal skog öppnas för skogsbruk i och med att nya tillfartsvägar byggs. Skogsbruket har avgörande betydelse för barbastellen i södra Sverige, precis som för nordfladdermusen i norr. Rik förekomst av gammal variationsrik löv- eller granskog är en förutsättning för barbastellen, eftersom den, till skillnad från odlad skog, innehåller både boplatser och en rik och pålitlig födokälla i form av nattfjärilar. Barbasteller rör sig över stora ytor och byter boplats ofta. De måste därför skyddas genom planering på landskapsnivå och med syftet att bevara och restaurera gammal artrik och åldersstrukturerad skog inklusive små rester av gammal granskog, sumpskog och åkerholmar. Att använda skyddszoner, inom vilka vindkraftverk inte får byggas, runt kända boplatser, vilket nu sker, är inte effektivt när det gäller att skydda barbasteller.D) Uppskattning av dödlighet av fladdermöss vid svenska vindkraftverk. Uppskattning av dödlighet utifrån eftersöksdata och experimentell bestämning av borttransport och sökeffektivitet har nu gjorts vid tre sydsvenska vindparker. Beräkningar av dödlighet på dessa platser varierar mellan 1 och 6 döda fladdermöss per kraftverk och år. Resultaten bygger fortfarande på små underlag och deras generalitet ska därför bedömas med hänsyn till detta.
22.	Rydell, Jens, et al. (författare) När natt blir dag : Belysning av av kyrkor och brunlångörats försvinnande - kunskapsunderlag för handläggning av artskydd 2021 Rapport (övrigt vetenskapligt/konstnärligt)abstract Äldre kulturbyggnader har nästan alltid inneboende fladdermöss. Ibland finns flera arter i olika delar av byggnaden. De kan finnas i tak, på vindar och i torn, i källarvalv eller i springor i fasaden, allt beroende på art och årstid. Den i särklass vanligaste arten i svenska kyrkor är brunlångöra Plecotus auritus. Sommartid bor de antingen enstaka (hanar) eller i kolonier med honor och ungar (yngelkolonier). Fladdermöss och deras boplatser har ett strikt skydd i EU, inklusive Sverige. Estetisk belysning (fasadbelysning) av kyrkor innebär en konflikt med artskyddsförordningen, eftersom den gör kyrkan obeboelig för fladdermöss. Den här skriften förklarar hur problemet uppstår och vad man ska göra åt det. Den är tänkt att vara en handledning för dem som på något sätt har att hantera fladdermöss i kyrkor och andra kulturbyggnade
23.	Rydell, Jens, et al. (författare) När natt blir dag : Belysning av kyrkor och brunlångörats försvinnande, kunskapsunderlag för handläggning av artskydd - reviderad 2021 Rapport (övrigt vetenskapligt/konstnärligt)abstract Äldre kulturbyggnader har nästan alltid inneboende fladdermöss. Ibland finns flera arter i olika delar av byggnaden. De kan finnas i tak, på vindar och i torn, i källarvalv eller i springor i fasaden, allt beroende på art och årstid. Den i särklass vanligaste arten i svenska kyrkor är brunlångöra Plecotus auritus. Sommartid bor de antingen enstaka (hanar) eller i kolonier med honor och ungar (yngelkolonier). Fladdermöss och deras boplatser har ett strikt skydd i EU, inklusive Sverige. Estetisk belysning (fasadbelysning) av kyrkor innebär en konflikt med artskyddsförordningen, eftersom den gör kyrkan obeboelig för fladdermöss. Den här skriften förklarar hur problemet uppstår och vad man ska göra åt det. Den är tänkt att vara en handledning för dem som på något sätt har att hantera fladdermöss i kyrkor och andra kulturbyggnader.
24.	Rydell, Jens, et al. (författare) Phenology of migratory bat activity across the Baltic Sea and the south-eastern North Sea 2014 Ingår i: Acta Chiropterologica. - 1508-1109. ; 16:1, s. 139-147 Tidskriftsartikel (refereegranskat)abstract We compiled the available information on the occurrence and timing of migratory bat activity across the Baltic Sea and south-eastern North Sea coasts and islands, based on ultrasonic monitoring projects at 19 localities in 2007-2009. The data refer to three species; Nathusius' pipistrelle Pipistrellus nathusii, soprano pipistrelle P. pygmaeus and common noctule Nyctalus noctula. Pipistrellus nathusii occurred at all sites (north to 61 degrees N in Finland), while the other species were scarcer, particularly at the northernmost sites. The status of the recorded individuals is unknown. However, the activity most likely was of migrating individuals or individuals on migration stopover, because very few observations were made during the maternity period. Spring activity occurred predominantly in May, with the median observation date of P. nathusii 20 days earlier in the south (Germany) than in the north (Finland). Autumn migration was observed throughout August and September and activity that may or may not indicate migration was also observed in October and November. The median date of such activity in autumn usually occurred in September and without any significant difference in timing in relation to latitude. Migratory bats in the Baltic area apparently move on a broad front in most cases. The estimated speed of migration for P. nathusii in spring was 55 km/day. The entire coastline and islands around the Baltic Sea are of potential importance for migrating bats in spring (April-May) and autumn (August-September) and should achieve relevant protection according to EU legislation and its implementations.
25.	Rydell, Jens, et al. (författare) Photography as a low-impact method to survey bats 2015 Ingår i: Mammalian Biology. - : Springer Science and Business Media LLC. - 1616-5047. ; 80:3, s. 182-184 Tidskriftsartikel (refereegranskat)abstract Bats are mammals of chief conservation concern and also represent potentially powerful bio-indicators. Surveying bats is thus an important task but the approaches adopted may either be too invasive (capture) or prone to identification errors (acoustic methods). We here report on the use of a photographic trap to survey bat species richness we tested at two drinking sites in central Italy. The species richness we estimated was similar to that obtained by a previous mist-netting effort at the same sites. We also photographed species often overlooked in acoustic surveys due to their faint echolocation calls. From the photographs we could frequently identify sex, reproductive status, age class and individual marks. Given the relative non-invasiveness of this approach, we strongly recommend it in lieu of capture at sensitive sites or to complement acoustic surveys in order to improve identification rates. (C) 2014 Deutsche Gesellschaft fur Saugetierkunde. Published by Elsevier GmbH. All rights reserved.
26.	Rydell, Jens, et al. (författare) Rovdjuren satte fart på evolutionen 2000 Ingår i: Forskning och Framsteg. ; 2/00, s. 29-33 Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
27.	Rydell, Jens, et al. (författare) Testing the performances of automated identification of bat echolocation calls : A request for prudence 2017 Ingår i: Ecological Indicators. - : Elsevier BV. - 1470-160X. ; 78, s. 416-420 Tidskriftsartikel (refereegranskat)abstract Echolocating bats are surveyed and studied acoustically with bat detectors routinely and worldwide, yet identification of species from calls often remains ambiguous or impossible due to intraspecific call variation and/or interspecific overlap in call design. To overcome such difficulties and to reduce workload, automated classifiers of echolocation calls have become popular, but their performance has not been tested sufficiently in the field. We examined the absolute performance of two commercially available programs (SonoChiro and Kaleidoscope) and one freeware package (BatClassify). We recorded noise from rain and calls of seven common bat species with Pettersson real-time full spectrum detectors in Sweden. The programs could always (100%) distinguish rain from bat calls, usually (68–100%) identify bats to group (Nyctalus/Vespertilio/Eptesicus, Pipistrellus, Myotis, Plecotus, Barbastella) and usually (83–99%) recognize typical calls of some species whose echolocation pulses are structurally distinct (Pipistrellus pygmaeus, Barbastella barbastellus). Species with less characteristic echolocation calls were not identified reliably, including Vespertilio murinus (16–26%), Myotis spp. (4–93%) and Plecotus auritus (0–89%). All programs showed major although different shortcomings and the often poor performance raising serious concerns about the use of automated classifiers for identification to species level in research and surveys. We highlight the importance of validating output from automated classifiers, and restricting their use to specific situations where identification can be made with high confidence. For comparison we also present the result of a manual identification test on a random subset of the files used to test the programs. It showed a higher classification success but performances were still low for more problematic taxa.
28.	Rydell, Jens, et al. (författare) The effect of wind power on birds and bats : A synthesis 2012 Rapport (övrigt vetenskapligt/konstnärligt)abstract The wind power industry almost certainly faces a considerable expansion within the near future in Sweden and elsewhere, and it is probably unavoidable that birds and bats will be killed or otherwise affected negatively to some extent. However, we believe that an increase in wind power production according to the national plan (30 TWh until the year 2020) is compatible with the preservation of viable populations of all bird and bat species in Sweden. The risk of negative effects can be limited considerably by planning and cooperation and by using the available information. On the other hand, there are also considerable gaps in our knowledge and these should be filled in order to minimize the uncertainties during future projects.We have reviewed the existing (2010) literature on the effects on wind farming on birds and bats in Europe and North America. The information has been analyzed with respect to species and groups of species, their occurrence and behavior and also according to the location and size of wind farms and wind turbines. The identified effects may be either direct, when animals are killed, or indirect, when their habitats are changed as a consequence of the establishment or operation of wind energy facilities. The indirect effects are believed to be relatively small for bats but they are probably the most important for birds. We have not reviewed effects arising from construction of power lines, extraction of materials for construction, changed hydrology and the like.A wind turbine in Europe or North America kills on average 2.3 birds and 2.9 bats per year. These are median values, however, and the variation is large (0-60 birds and 0-70 bats) and the distribution uneven (bimodal). While most wind turbines actually kill none or very few birds and bats, some turbines kill many. The location of a wind farm in relation to the local topography and surrounding habitat is the primary determinant of the number of birds and bats that will be killed.By far the most important measure that can be taken to minimize the risk of negative effects on birds and bats is to identify the dangerous locations and avoid locating wind turbines there. Most accidents with birds occur in places where they concentrate, such as near wetlands and bodies of water, but sometimes also in elevated sites including peaks and ridges of hills and mountains. For bats the most dangerous locations include coastlines and the top of distinct hills, but linear landscape elements such as lake shores, rivers, motorways, and, on a smaller scale also tree-lines, hedgerows and the like should also be considered as potentially risky. In contrast, in areas of intensively managed forest or open farmland the effect of wind turbines on birds and bats are usually small, particularly in flat terrain.Most future wind farm establishments in Sweden will probably be allocated to elevated sites within any of the two major forest regions. Such locations are generally not considered dangerous for birds and bats, but recent evidence from Germany and USA suggests that wind turbines located in such places sometimes are very dangerous to bats. Unfortunately, there is no information on the reaction of bats to wind turbines at high elevation forest sites in Sweden. This requires investigation as soon as possible.All flying birds may potentially collide with wind turbines. However, raptors, grouse and their allies, and also gulls and terns tend to collide more often than expected from their occurrence and numbers. Birds that breed, stop over or overwinter in a particular area, and thus spend more time there, face a higher risk to collide with wind turbines, compared to birds that pass over during migration. The fatality rate at a certain wind farm generally does not decline with time, which indicates that birds do not learn to handle the problem.There is no evidence that present or planned (30 TWh until 2020) wind farming in Sweden will affect any bird population at the national level, although eagles and other large raptors, as well as some waders, could possibly be affected locally or regionally. Nevertheless, particular attention is needed in areas where raptors are concentrated and in places with higher densities of breeding waders such as coastal meadows, bird islets and some bogs and mountain locations.Birds, with the possible exception of swallows and swifts, are normally not attracted to wind turbines. Instead, they either avoid or ignore such installations, and this applies both to land based and off shore wind farms. During the breeding season the disturbance range is usually short or difficult to determine, but its presence is more obvious in waders than in other birds. Furthermore, it is more obvious at other times of the year, particularly in water birds that live in flocks, including divers, geese, ducks and waders. Disturbance reactions usually become obvious within 100-500 m from the turbine, but for some birds such as divers, the distance can be longer.Bird densities in areas used for wind farming may either decrease or increase with time. We have been unable to find any general trends in this respect, however, although many high quality studies have been reviewed. The same situation applies to habituation, which means that the behavioral disturbance effects may either increase or decrease with time. If the densities and behavioral effects increase, decrease or remain stable over time seems to depend on the bird species in question and the particular situation.Migrating seabirds usually avoid flying close to wind turbines both in daytime and at night. In daylight, obvious changes in the flight paths occur at 1-2 km (sometimes 5 km) from the turbines, but at night the reaction becomes obvious only at 0.5-1 km. The change in flight direction may lead to barrier effects and hence longer flight paths around the wind farms. On the other hand, accidents with migrating seabirds at marine wind farms seem to be very rare.Bats are killed at wind turbines as they hunt for insects that accumulate around the turbine towers. The immediate causes of death may be either fractures resulting from collision with the rotor blades, or ruptures of blood vessels or lungs visible as internal hemorrhaging. In the latter case, the damage is caused by rapidly falling air pressure behind the rotor blades. The accidents usually (90%) occur during warm nights with slow wind speed in late summer and autumn (late July to September), but sometimes also in spring (May to early June). Very few bats are killed at wind farms in the middle of the summer and during the winter season. Like bats, swallows and swifts are also killed while feeding on insects at wind turbines, but the extent of this is unknown and needs to be investigated.Accidents with bats at wind farms are predictable with respect to the time of day and prevailing weather conditions and usually occur during a limited part of the year (late summer) as well. In contrast, accidents with birds at wind farms tend to occur throughout the year and without any obvious coupling to the season and prevailing weather conditions. This difference between birds and bats is fundamental and implies that the two groups of animals should be handled separately with respect to wind farming. The continued use of a wind turbine that proves to be dangerous for bats may perhaps be facilitated, providing a mitigation scheme is worked out. This seems to be more difficult to do for birds, because their contact with wind turbines is more unpredictable in general and also highly variable among species. Hence, careful consideration of the turbine location before construction is most important for birds.Bats occasionally hunt migrating or drifting insects that form local swarms at wind turbines far out at sea, but if this behavior results in bats being killed at marine wind farms has not been investigated. However, the behavior of bats at offshore wind turbines is similar to that observed at wind turbines on land, so until evidence is available we should expect that the risk of being killed is also similar.The risk that bats are killed at wind turbines varies strongly from species to species. For some species, fatalities are rare or occasional, while other species are much more vulnerable. The high-risk species are adapted to catch insects in the open air and include the common noctule, the parti-colored bat, the northern bat and the pygmy pipistrelle and also their rarer relatives Leisler´s bat and the common and Nathusius´ pipistrelles. These species together comprise as much as 98% of all fatalities of bats at north European wind farms. Other species, some of which are very common, seem to spend less time at heights where they are at risk to collide with turbine rotor blades. Nevertheless, there are a few species, notably the barbastelle, which are hard to categorize. They occur in scarce or small populations, which in itself could be the main reason why they are rarely found dead at wind turbines.Taller turbines kill more bats compared to lower turbines, but this does not seem to apply to birds, perhaps with the exception of certain raptors. The modernization of older wind power facilities usually means that the turbines become higher and more efficient but possibly fewer. Hence modernization of older wind farms may result in lower risks for birds in general but at the same time, the risk for bats and possibly raptors probably increases. Otherwise, the fatality rate, defined as the number of fatal accidents per turbine and year, does not seem to be related to the construction or lighting of the turbines or to their internal location within the wind park. Likewise, we found no evidence that the fatality rate depends on the distance between the rotor and the ground or on the size of the wind farm (number of turbines).To evaluate the possible impact of future wind farming on bat populations in Sweden, we developed a simple mathematical model.
29.	Rydell, Jens, et al. (författare) The effects of wind power on birds and bats : an updated synthesis report 2017 2017 Rapport (övrigt vetenskapligt/konstnärligt)abstract 1. Since the previous report on the impact from wind power on birds and bats was published in 2011, much new and important information have appeared both internationally and in Sweden. The present report is a summary of the international research in this area in recent years, and also of the Swedish post-construction surveys made until 2015. This report is hence an update of the previous (2011) report.2. With respect to birds, the results of new research largely confirm the conclusions from the previous report. For bats, however, new results show that wind power is a larger problem than we realized five years ago, but, on the other hand, new mitigation methods have recently been developed and tested, so that the problem can now be handled more efficiently.3. Wind power facilities are generally a larger problem for bats than for birds. This is because more bats are being killed, and also because the mortality is concentrated to a few species of bats, which therefore may be affected seriously. At the same time, wind power facilities can also be a problem for certain kinds of birds, some of which may be affected negatively at the population level. Common for birds and bats that risk being negatively affected at the population level is that they have low reproductive potential, and therefore may have difficulties compensating for increased mortality.4. The fatality rate of birds at wind turbines remain at 5–10 birds per turbine and year on average, even after several and more detailed surveys that have been conducted recently. The location of the turbine is often an important determinant of the fatality rate. While most turbines kill few birds, others may kill up to 60 birds per year. So far there is only one study from Sweden that has been executed in sufficient detail to allow estimation of annual fatality rates. This study was conducted at Näsudden on the island of Gotland, a coastal site very rich in birds, and show, as expected, fatality rates much higher than average. Regarding fatality rates of birds and bats at marine wind farms, no new evidence-based knowledge have been presented since the previous report.5. Bird mortality at wind turbines generally increases with the size of the turbines. However, in relation to installed effect and produced electricity the mortality declines with increased turbine size. As fewer new, large plants replace old, small ones, the total mortality per wind farm can be lowered at the same time as the electricity production increases. This was the case at Näsudden when the old turbines were replaced by new ones. If a similar effect also is achieved for bats has not been investigated.6. All kinds of birds can be killed at wind turbines. Also, birds are probably killed at all sites where modern wind turbines are being used. Most fatalities are small songbirds. Raptors, gulls and game birds are killed at higher rates than expected based on their population sizes. Relatively few swan, geese and cranes are killed at wind turbines, probably because these birds show strong avoidance behaviours. Relatively few birds are killed while in flight during migration. Generally, mortality is higher for birds that stay in an area over longer periods such as during breeding, wintering or at stopovers during migration.7. Estimates of fatality rates for bats at wind turbines presented in 2011 were much too low. New research from Europe and North America suggest that on average a wind turbine kills 10–15 bats per year, in some cases up to 100 or more. We still have no comparable estimates from Sweden, but an ongoing study from a site in Halland suggests that the fatality rate is about 5 bats per turbine and year at that site.8. Mortality of bats at wind turbines is limited to a few species that move and feed in the open air above the tree-canopies. We call them high-risk species. The consideration of bats at wind turbines should focus on them. The noctule, the parti-colored bat and in the north also the northern bat are those that we believe are in most need of concern, but the soprano-, common and Nathusius’ pipistrelles as well as the rarer Leisler’s bat and serotine are also high-risk species and thus potentially affected. Remaining species are rarely or never killed at wind turbines.9. There have been some recent attempts to investigate if the mortality caused by wind turbines has negative population effects on bird species. In USA it was found that present wind farms probably do not affect any national population of songbirds. Similar results were obtained for Canada, but in this case the results applied to all breeding birds. No such broad studies have been made in Europe, but estimates have been made for species considered as particularly vulnerable. In northern Germany, with particularly many wind farms in operation, it is believed that the populations of red kites and common buzzards are already being affected negatively and this may perhaps apply to the white-tailed eagle as well.10. We still have no estimates of population sizes for bats in Sweden or internationally and therefore we cannot evaluate if and how the increased mortality from wind turbines affects bat populations. However, there are concerns from North America and Europe that serious negative effects on bat populations of certain species already have occurred.11. Recent results from studies on the impact of wind turbines on habitats, avoidance and disturbance of birds confirm the pattern from the previous report. There is large variation among different species, areas and habitats and general conclusions are difficult to draw. Nevertheless, avoidance behaviour is usually less obvious during the breeding season compared to the rest of the year. During the breeding season avoidance is usually obvious only within a few 100 m, the greatest distances are found among waders. During other parts of the year, it is birds that live in flocks and certain marine birds that show the greatest avoidance distances. Nothing new has appeared regarding habituation of birds to wind turbines and there is still considerable variation between different studies. There are some recent studies suggesting that the distance and habitat between the turbines affect the degree of avoidance behaviour and disturbance. Marine wind farms are avoided by most marine birds, but some species (cormorants and gulls) are attracted to the turbines, probably because the towers provide resting sites or access to food. Long-term studies of avoidance and disturbance are still lacking.12. Impact on the habitats, avoidance behaviour and disturbance has not been investigated with respect to bats so far and may generally be less of a problem for bats than for birds. It is nevertheless obvious that drastic physical changes of the habitat will have effects also on bats, one way or another. On the contrary, it is clear that bats are attracted to wind turbines and that they search for them actively, in contrast to birds, which means that the problem usually requires different solutions for the two groups of animals.13. Measures to minimize negative impact on birds are still mostly focused on avoiding building wind turbines in places that are rich in birds, particularly sites with high numbers of birds during breeding, wintering and stopovers during migration. Areas around specific occurrences and breeding sites of birds belonging to species or groups of species that have turned out to be particularly vulnerable to negative impact from wind turbines should be avoided. One such example is the larger raptors. Maintaining buffer zones, areas within which wind turbines should not be built, is a way to reduce the risks in such cases. In this report we review the current use of protection zones for birds and provide new suggestions for their future application. We discuss how we can achieve new and more scientifically based protection zones, particularly for our eagles. We appreciate that protection zones is a useful way to reduce the risks for some birds, but at the same time we emphasize that that this method cannot eliminate the risks entirely.14. Although we consider buffer zones as an effective and practically useful way to reduce negative impact on particular birds, we and many other scientists are realising that this method may not always be sufficient for the protection and formation of viable populations of the species in question. To achieve such goals, planning at a larger scale may be necessary, where areas with the lowest risks of negative environmental impacts are designated suitable for e.g. establishment of wind farms. We believe that this would increase the efficiency of the planning and handling processes during wind turbine establishment and also facilitate the protection of both birds and bats, in comparison with current practices. This would also ensure that sufficiently large areas with relatively low risks are maintained for long-term conservation of (bird and bat) populations.15. Once the turbines are built the available mitigation options are few when it comes to protection of birds. To mitigate by temporary halting the turbines during periods of high risk, as employed for bats, is a less useful method for birds. For birds there is no clear and general relationship between prevailing conditions on one hand, and the mortality risk on the other, which is in sharp contrast to the situation for bats. Although there are some cases from other countries where wind turbines have been halted to protect birds, this method do not seem to be useful in Sweden, as far as we can see. However, there is a promising development of various technical monitoring solutions that aim to keep bird fatalities at a very low level. As far as we know, no such system is yet fully developed and operational, but this is probably only a matter of time. Finally we also have the option of using compensation measures at a different site, a method that may help minimize the total e
30.	Rydell, Jens, et al. (författare) Vindkraftens påverkan på fåglar och fladdermöss : Uppdaterad syntesrapport 2017 2017 Rapport (övrigt vetenskapligt/konstnärligt)abstract 1. Sedan den första syntesrapporten om vindkraftens effekter på fåglar och fladdermöss publicerades 2011 har en hel del ny och viktig kunskap tagits fram både internationellt och i Sverige. Den här rapporten är en sammanställning av internationell forskning under senare år samt av de svenska kontroll- och uppföljningsprogram som genomförts fram till 2015/2016. Rapporten är en uppdatering av den tidigare syntesrapporten.2. Nya resultat befäster i stort sett slutsatserna från den första syntesrapporten 2011 när det gäller fåglar. När det gäller fladdermöss visar ny kunskap å ena sidan att vindkraften är ett större problem än vad vi trodde för fem år sedan. Å andra sidan har nya metoder för att begränsa skadorna hunnit utvecklas och testas så att vi nu kan hantera problemet bättre.3. Vindkraft är generellt sett ett större problem för fladdermöss än för fåglar. Detta beror dels på att fler fladdermöss dödas, men också på att dödligheten koncentreras till några få arter som därmed riskerar att påverkas kraftigt. Samtidigt kan vindkraft också innebära problem för, och populationspåverkan på, vissa typer av fåglar. Gemensamt för de fåglar och fladdermöss där det finns risk för negativ påverkan på populationsstorlekar är att de har låg reproduktionspotential, vilket innebär att de kan förväntas få svårt att kompensera för en kraftigt ökad dödlighet.4. Genomsnittsvärden för antalet dödade fåglar per vindkraftverk och år ligger även efter nya och mer detaljerade undersökningar kvar på mellan fem och tio per kraftverk och år. Vindkraftverkens läge har ofta betydelse för hur många fåglar som dödas. Medan vissa verk dödar mycket få fåglar, kan andra orsaka upp till ca 60 fåglars död per år. Än så länge finns endast en enda svensk studie som genomförts så pass noggrant att det går att beräkna den årliga dödligheten. Denna gjordes vid Näsudden på Gotland, ett mycket fågelrikt område, och visar inte helt oväntat på en dödlighet som ligger klart högre än i medelfallet. Miljön där vindkraftverken står är av betydelse för hur många fåglar som dödas och allra högst dödlighet har funnits i anslutning till våta miljöer, såsom vid Näsudden. Det har inte kommit någon ny faktabaserad kunskap om dödligheten vid marina vindkraftverk, vare sig för fåglar eller för fladdermöss.5. Fågeldödligheten ökar med verkens storlek, ett resultat som visats internationellt och som stöds av studierna på Näsudden. Sett i förhållande till installerad effekt och producerad mängd el minskar dock dödligheten med ökande verksstorlek. Då det dessutom behövs färre nya, stora verk jämfört med gamla, små verk för att producera samma mängd el kan man minska den totala dödligheten per anläggning samtidigt som elproduktionen ökas. Detta blev fallet vid Näsudden när man bytte ut äldre verk mot nya. Om effekten blir densamma när det gäller fladdermöss har inte undersökts.6. Alla typer av flygande fåglar kan dödas vid vindkraftverk, inga är immuna. Fågeldödlighet förekommer också vid alla platser där vindkraftverk av de typer vi använder idag finns. Det finns sannolikt inga platser där dödlighet aldrig förekommer. De allra flesta fåglar som dödas av vindkraftverk är vanliga småfåglar. Rovfåglar, måsar, trutar och hönsfåglar dödas i högre omfattning än förväntat i förhållande till populationsstorlekarna. Förhållandevis få svanar, gäss och tranor förolyckas, troligen eftersom dessa grupper uppvisar starka undvikandebeteenden. Relativt få fåglar förolyckas under aktiv flyttningsflykt. Dödligheten är generellt högre för fåglar som vistas i ett område under längre tid såsom under häckning, övervintring eller rastning under flyttningstid.7. De siffror på dödlighet av fladdermöss vid vindkraftverk som presenterades 2011 var för låga. Nya undersökningar i Europa och Nordamerika har visat att i genomsnitt dödar varje vindkraftverk 10–15 fladdermöss per år. Vi har fortfarande inga jämförbara siffror från Sverige, men preliminära resultat från en vindpark i Halland visar på fem dödsfall per kraftverk och år på den platsen.8. Dödlighet av fladdermöss vid vindkraftverk är nästan helt begränsad till arter som rör sig och jagar i fria luften över trädtoppshöjd. Dessa arter kallar vi högriskarter. Hänsyn till fladdermöss vid vindkraftverk skall fokuseras till dessa arter. Större brunfladdermus, gråskimlig fladdermus och i norr kanske även nordfladdermus bedömer vi vara i störst behov av hänsyn. Men även dvärg-, syd- och trollpipistrell samt de sällsynta arterna mindre brunfladdermus och sydfladdermus är högriskarter och riskerar därmed att påverkas negativt. De övriga svenska fladdermusarterna dödas sällan eller aldrig vid vindkraftverk.9. Under senare tid har det gjorts ett antal ansatser till att analysera om dödligheten orsakad av vindkraftverk påverkar populationsstorlekar för fåglar. I Nordamerika fann man att dagens befintliga vindkraftverk sannolikt inte påverkar storleken på något av kontinentens småfågelbestånd. Liknande resultat hittade man specifikt för Kanada, men då för samtliga häckande fågelarter. I Europa har man inte gjort några lika övergripande analyser, men istället specifikt analyserat arter som bedöms vara särskilt utsatta. I norra Tyskland bedöms att redan i dag är dödligheten vid vindkraftverk så hög totalt sett, med väldigt många vindkraftverk i drift, att den påverkar antalet röda glador och ormvråkar negativt. Sannolikt gäller detta även för antalet havsörnar.10. Det finns fortfarande inga mått på storleken på fladdermuspopulationer, vare sig inom Sverige eller internationellt, och därför kan man inte göra några tillförlitliga beräkningar av hur vindkraftdödligheten påverkar bestånden. Det finns farhågor både från Nordamerika och från Europa om att kraftig negativ påverkan på populationsstorlekarna av ett antal fladdermusarter på grund av vindkraftorsakad dödlighet redan kan ha skett.11. Sentida resultat om påverkan på livsmiljö, undvikande och störning från vindkraftverk på fåglar visar på samma mönster som vi angav i den förra syntesrapporten. Det är stor variation mellan olika arter, olika områden och olika miljöer. Generella slutsatser är svåra att dra, men allmänt sett förefaller undvikande vara lägre under häckningstid än under övriga delar av året. När undvikande under häckning förekommer rör det sig i regel om avstånd på upp till några 100 m. Vadare uppvisar de största undvikandeavstånden under häckningstid. Under andra delar av året är det fåglar som lever i flockar samt en del marina fåglar som visar de allra största undvikandeavstånden. Inget direkt nytt har framkommit när det gäller om fåglar vänjer sig vid vindkraftverk eller inte. Även på den punkten varierar resultaten mellan olika studier. Några senare undersökningar antyder att avstånd mellan verk samt miljön mellan verk påverkar graden av undvikande och störning. Vid marina parker är det fortsatt så att flertalet marina fåglar visats undvika dessa. Ett mindre antal arter (skarvar och måsfåglar) attraheras till vindparker, sannolikt eftersom dessa erbjuder viloplatser och kanske även förbättrade födosöksmöjligheter. Långtidsstudier av påverkan på livsmiljö, undvikande och störning från vindkraftverk på fåglar saknas i stort.12. Påverkan på livsmiljö, undvikandebeteende och störningar har inte avhandlats i några studier av fladdermöss så här långt och har sannolikt betydligt mindre betydelse för denna djurgrupp än för fåglar. Samtidigt är det självklart att en rent fysisk förändring av livsmiljön påverkar även fladdermöss på något sätt. Å andra sidan har man visat att fladdermöss attraheras till vindkraftverk och söker upp dem aktivt. Detta är en stor och viktig skillnad jämfört med fåglar och gör att problemet måste hanteras på ett annat sätt.13. Åtgärder för att minska negativ påverkan på fåglar från vindkraft handlar fortfarande i första hand om att undvika att bygga vindkraftverk på särskilt fågelrika platser, speciellt sådana som används under häckning, övervintring eller rastning under flyttningen. Det handlar också om närområden kring förekomster, häcknings- eller boplatser av arter och grupper av fåglar som visats löpa högre risker för negativ påverkan från vindkraft. Exempel på sådana är större rovfåglar. Så kallade skyddsavstånd, zoner där inga vindkraftverk bör byggas, är ett sätt att minska riskerna i sådana fall. Vi går i denna rapport igenom tidigare föreslagna skyddsavstånd, ger nya förslag på sådana, samt diskuterar på vilket sätt och med vilken faktabakgrund man skulle kunna komma fram till mer vetenskapligt grundade skyddsavstånd, särskilt för våra örnar. Vår utgångspunkt här är att skyddszoner är ett bra sätt att minska risker, men samtidigt ska man vara medveten om att det inte är och aldrig har varit avsikten att skyddszonerna ska eller kan ta bort riskerna helt och hållet.14. Samtidigt som vi anser att skyddsavstånd är ett verkningsfullt och praktiskt användbart redskap för att minska risker för negativ påverkan på vissa typer av fåglar, lyfter vi och ett ökande antal forskare också frågan om att detta kanske inte är tillräckligt för att bevara eller skapa livskraftiga bestånd av de arter vi vill ha. För att nå sådana mål menar vi att det krävs en mycket mer storskalig planering där man från centralt håll pekar ut de områden där en utbyggnad av exempelvis vindkraft ger så liten negativ miljöpåverkan som möjligt. Vi menar att detta skulle kunna leda till en smidigare hantering av ansökningsärenden för vindkraft, samtidigt som det skulle gagna fågelskyddet, i jämförels
31.	Sánchez-Navarro, Sonia, et al. (författare) Bat Fatalities at Wind-Farms in the Lowland Mediterranean of Southern Spain 2020 Ingår i: Acta Chiropterologica. - 1508-1109. ; 21:2, s. 349-358 Tidskriftsartikel (refereegranskat)abstract Wind energy is an important source of bat mortality worldwide. Extensive mortality data were gathered by a provincial surveillance program carried out at wind farms in lowland Mediterranean areas of the province of Cadiz, Andalusia (South Spain) between 2005 and 2016. As many as 2,371 bat fatalities were found. We determined the patterns of fatality in this sample and tested the quality of the surveillance program used. The data generally support previous observations regarding the seasonal timing, the species affected and the sex and age of fatalities. However, contrary to studies made at higher latitudes, fatalities mostly (95%) affected sedentary species and occurred on wind farms in flat landscape used for farming and livestock rearing. The current operational surveillance programme did not focus on bats initially, and, consequently, we urge that an improvement should consider a standardized search methodology including bats, verification of species identity, precise data collection, and mandatory and regular scavenger-removal and search-efficiency trials, in order to obtain correctly adjusted fatality estimates that can be used for efficient mitigation or compensatory measures.
32.	Sánchez-Navarro, Sonia, et al. (författare) High bat fatality rates estimated at wind farms in southern Spain 2023 Ingår i: Acta Chiropterologica. - 1508-1109. ; 25:1, s. 125-134 Tidskriftsartikel (refereegranskat)abstract An astonishing number of bat fatalities (2,371 belonging to 15 species) were recovered in a provincial surveillance program at wind farms in Cádiz, at the southern tip of Spain, in 2005–2016. We carefully analysed a subset of this sample intending to estimate the true fatality rate in the year 2011, the year for which we had the richest data set (582 fatalities at 38 wind farms). To estimate the true fatality rate, we conducted search-efficiency and scavenger-removal trials in nine wind farms involving 122 turbines and 289 observed fatalities and calculated the searchable surface. An annual fatality rate of 41.1 dead bats per turbine (26.4 per MW) was estimated in the study area using a self-developed estimator due to the singularities of the surveillance program. Our estimator results are lower than those obtained using the Generalized Mortality Estimator (GenEst) developed by U.S. Geological Survey. Estimates of 37,689 or 33,370 fatalities were made according to the province's number of turbines or MW in 2011. Some areas have registered the highest fatality rates ever recorded for bats in wind turbines anywhere globally, even more so because we have been conservative. There is an urgent need for efficient preventive and mitigation measures at wind farms in risky landscapes and with a high rate of bat fatalities, but trials are also needed to know how well the post-operational monitoring is done and how far it is from reality. Clearly, current official post-construction surveillance programs are inefficient for searching bats and therefore mask a high fatality rate, mainly of sedentary bats.
33.	Suba, Jurgis, et al. (författare) Fly-and-forage strategy in the bat Pipistrellus nathusii during autumn migration 2012 Ingår i: Acta Chiropterologica. - 1508-1109. ; 14:2, s. 379-385 Tidskriftsartikel (refereegranskat)abstract Populations of Pipistrellus nathusii (Nathusius's bat), an insectivorous aerial-hawking species that breeds in north-eastern Europe, perform long-distance migrations between breeding sites and hibernation areas in central and southern Europe. The feeding strategy of migrating P nathusii was investigated in Latvia on the east coast of the Baltic Sea, exploring evidence for and against two non-mutually exclusive predictions that i) the bats feed shortly after dusk at highest aerial insect activity and continue to migrate thereafter or ii) apply a 'fly-and-forage' strategy and frequently interrupt their migration flight to feed. Echolocation calls and feeding buzzes of P. nathusii were recorded throughout the night from August until September on a known migration flyway over coastal dunes and at potential foraging sites in adjacent woodlands, over meadows and wetlands. The results indicate that P. nathusii applies a fly-and-forage strategy along the Baltic coast. However, a threshold in aerial insect availability may exist, below which no foraging occurs and migration continues.
34.	Voigt, Christian C., et al. (författare) The Impact of Light Pollution on Bats Varies According to Foraging Guild and Habitat Context 2021 Ingår i: BioScience. - : Oxford University Press (OUP). - 0006-3568 .- 1525-3244. ; 71:10, s. 1103-1109 Forskningsöversikt (refereegranskat)abstract We Review How Different Bat Guilds Respond To Artificial Light At Night (Alan) And Assess How The Impacts Can Vary According To Ecological Context. All Studied European Species Respond Negatively To Alan Close To Roosts And Drinking Sites, And The Impacts Occur Across A Wide Range Of Light Colors And Intensities. Most Bat Species Are Sensitive To Alan When Commuting And Foraging. Although Narrow-Space-Foraging Bat Species Consistently Avoid Alan When Foraging, Open And Edge-Space-Foraging Species May Exploit Insects Lured By Alan. Therefore, Alan Acts As An Environmental Filter On Bat Assemblages. Considering The Detrimental Effect Of Alan On Insects, We Conclude That Alan Probably Has Negative Impacts On All Bat Species, Even On Those Foraging At Streetlights. The Sprawl Of Alan May Be A Key Factor Driving The Decline Of Bat Diversity Globally, And The Current Trajectory Of Increasing Alan Is Therefore Of Considerable Concern For Bat Conservation.

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