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Bats and their insect prey at streetlights

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... Il peut être intéressant de parcourir des secteurs résidentiels où les arbres sont matures et abondants. Les lampadaires sont connus pour être fréquentés par les chauves-souris en raison des concentrations d'insectes attirés par la lumière (Belwood et Fullard, 1984;Rydell, 2006;Jung et Kalko, 2010;Minnaar et coll., 2015;Owens et coll., 2019). En effet, chez les chauves-souris peu lucifuges 12 (chauve-souris argentée, chauve-souris rousse, chauve-souris cendrée et grande chauve-souris brune), cet élément est positif, car elles s'approchent des lampadaires qui attirent les insectes (Le Gouil, 2012). ...
... Les lampes au mercure produisent une lumière très blanche qui attire abondamment les insectes alors que les lampes au sodium produisent une lumière plus ambrée et attirent peu ces derniers (Rydell, 1992(Rydell, et 2006. Dans les villes, les lampadaires au mercure ont graduellement été remplacés par ceux au sodium (lumière ambrée) ou les nouveaux modèles, dont les lampes LED (lumière blanche ou blanc doux), si bien que les lumières ambrée ou blanc doux sont devenues fréquentes en milieu urbain. ...
... Avec une pollution lumineuse importante, on observe peu d'effet de la pleine lune sur le comportement d'alimentation des chauves-souris. Cependant, dans les milieux où cette pollution est faible, quelques études démontrent un effet négatif de la pleine lune sur le comportement d'alimentation (Belwood et Fullard, 1984;Rydell, 2006;Jung et Kalko, 2010;Minnaar et coll., 2015;Owens et coll., 2019), bien que le doute persiste (Le Gouil, 2012). Par ailleurs, il semblerait que l'activité nocturne des insectes soit également réduite en phase de pleine lune (Williams et Singh, 1951). ...
... Por otra parte, el efecto del desarrollo urbano en áreas cercanas a remanentes de bosques sobre los murciélagos insectívoros parece depender de la especie (Jung & Kalko, 2010). Así, algunos murciélagos, parecen tolerar las urbanizaciones y aprovechan la presencia de luces artificiales, que atraen insectos, como sitios de forrajeo, aunque la rentabilidad parece ser mejor alrededor de las lámparas de luz blanca, que alrededor de las de luz amarilla-naranja (Jung & Kalko, 2010;Rydell, 2006); sin embargo, los murciélagos también pueden ser perjudicados por las áreas urbanizadas, que vienen asociadas con la construcción de vías y éstas pueden ser agentes de mortalidad para los murciélagos insectívoros que sufren el riesgo de estrellarse con los vehículos (Lodé, 2000;Russell et al. 2009). Por lo tanto, el desarrollo urbanístico puede, potencialmente, tener efectos positivos y negativos sobre las poblaciones de murciélagos insectívoros. ...
... Adicionalmente, los lugares con lámparas: en Torca, en Las Mercedes y en la U.D.C.A lograron niveles de forrajeo mayores, a los registrados en los otros lugares. Así, los resultados también indican que los puntos de observación con iluminación artificial son usados como parches de forrajeo por parte de los murciélagos, como ocurre en otras áreas urbanas y semiurbanas del neotrópico Cómo ya se mencionó, las lámparas, en particular las de luz blanca, se convierten en parches alimentarios, valiosos para los murciélagos insectívoros, en ambientes urbanos o semiurbanos, dado que atraen y acumulan insectos a su alrededor y actúan mejor cuando están rodeadas de ambientes naturales o similares (Gaisler et al. 1998;Rydell, 2006). Así, las lámparas son aprovechadas en el norte de Figura 3. A. Actividad de forrajeo de los murciélagos insectívoros (fases de terminales/5 min), alrededor de un edificio con lámparas de luz blanca en la U.D.C.A. Las barras son promedios ± error estándar; barras con letras diferentes indican diferencias significativas (Prueba de Bonferroni, p<0,05). ...
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RESUMEN El borde norte de la Bogotá, Colombia, es un mosaico de ecosistemas transformados (urbanizaciones, cultivos, pastizales) y ecosistemas naturales (bosques andinos, humedales). En la actualidad, no se conoce cómo dicha heterogeneidad espacial afecta la ecología de las especies silvestres que sobreviven en la ciudad. Se propuso, que la heterogeneidad del paisaje del norte de Bogotá afecta el patrón temporal de actividad de los murciélagos insectívoros y su uso de hábitat. Se esperaba encontrar diferentes patrones de actividad temporal y de uso en sitios con diferentes grados de alteración humana. Se hicieron inspecciones acústicas en sitios con remanentes naturales, sitios con iluminación artificial y cercana a vías para automóviles. Los murciélagos insectívoros se registraron, tanto en áreas con remanentes naturales como intervenidas a lo largo del norte de Bogotá. La actividad de los murciélagos insectívoros cerca a vías importantes aumentó al avanzar la noche, mientras que en sitios sin vías principales fue en las primeras horas de la noche. Esto sugiere, que los murciélagos evitan zonas con alto flujo vehicular y estas vías reducen la disponibilidad de hábitats para los murciélagos insectívoros, al menos, en las primeras horas de la noche. Los sitios con iluminación artificial concentraron mayor actividad de forrajeo que sitios sin ella. La iluminación artificial parece beneficiar a algunos murciélagos, que encuentran allí parches, donde se acumulan sus presas potenciales y, es posible, que dicha iluminación se pueda usar en áreas agrícolas de la ciudad, para el control de poblaciones plaga, con la ayuda de los murciélagos.
... Route observations conducted by us to monitor bat activity in the city of Tomsk showed that in 87.5% of parti-coloured bat detected cases night lighting was present. Rydell [17] published similar results in the Swedish study of bats, showing that numbers of V. murinus were 3-20 times greater in illuminated areas. ...
... The main diet of the V. murinus includes Lepidoptera, Homoptera, Coleoptera, Trichoptera and Diptera [21][22][23] which are known to be attracted to artificial light [18]. Near the light sources, the bats can choose larger prey, thus increasing the energy efficiency of hunting [17,24,25]. Indeed, studies on the diet of the northern bat (Eptesicus nilssonii) in different lighting conditions confirmed greater cumulative gross energy intake in lit streets 0.5 kJ min −1 , contrasting with 0.2 kJ min −1 [26,27] in the natural environment. ...
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The impact of the anthropogenic environment on the fecundity of the bat is poorly understood. Therefore, in this study we chose the parti-coloured bat Vespertilio murinus – synanthrope, which is known to produce 1–4 pups, to assess that association. We compared the litter sizes of V. murinus among synanthropous maternity colonies associated with urban and rural habitats. Two colonies were examined from the city and two colonies in suburbs, with a total of 144 individuals. Larger litter size (2.7–2.9 pups per female) was observed in urban colonies, compared to 1.8 in rural colonies. We hypothesise that specific micro- and mesoclimatic conditions along with artificial light could predict that difference, and thus could reduce the time spend in estivation, stimulate higher milk production in lactating females and accelerate juvenile growth. Artificial urban light may secure abundant and affordable food for females, producing larger offspring.
... Stone, Wakefield, Harris, and Jones (2015), working in conjunction with CCCs "Invest-to-Save" project, found that activity of common pipistrelles, Pipistrellus pipistrellus, increased around MH lights following the switchover from LPS lights. As these bats hunt insects around lights (Rydell, 2006), and many insects are disproportionately attracted to UV light (Barghini & de Medeiros, 2012), this higher bat activity is likely to be a result of higher prey abundance at UV-emitting, broadspectrum MH lights. Relative to sodium lights, white lighting is predicted to: increase the bandwidth of wavelengths to which species are visually sensitive; alter species interactions (Davies, Bennie, Inger, Hempel de Ibarra, & Gaston, 2013); and to "exacerbate ecological impacts" of street lights (Pawson & Bader, 2014). ...
... As well as attracting insects and creating local abundances of prey for predators such as bats (Rydell, 2006), white street lights can also interfere with the predator avoidance behaviour of a number of moths, reducing their ability to avoid hunting bats (Svensson & Rydell, 1998;. The underlying causes of insect attraction to light remain unclear, but spectral changes to street lights will have significant impacts on various taxa, altering species distributions, wildlife communities and predator-prey interactions. ...
Article
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Sodium street lights, dominated by long wavelengths of light, are being replaced by broad-spectrum, white lights globally, in particular light-emitting diodes (LEDs). These white lights typically require less energy to operate and are therefore considered “eco-friendly”. However, little attention has been paid to the impacts white lights may have upon local wildlife populations. We compared insect attraction to orange (high-pressure sodium, HPS) and white (metal halide, MH and LED) street lights experimentally using portable street lights and custom-made flight intercept traps. Significantly more (greater than five times as many) insects were attracted to white MH street lights than white (4,250 K) LED and HPS lights. There was no statistical difference in the numbers of insects attracted to LED and HPS lights for most taxa caught. However, rarefaction shows a greater diversity of insects caught at LED than HPS lights. Policy implications. With the current, large-scale conversion to white light-emitting diode (LED) lighting, our results give insight into how changes to street light technology may affect wildlife populations and communities. We recommend avoiding metal halide light installations as they attract many more insects than competing technologies. We highlight the need to tailor LED lighting to prevent disturbances across multiple insect taxa. © 2017 The Authors. Journal of Applied Ecology Published by John Wiley & Sons Ltd on behalf of British Ecological Society
... Roadside lighting may also reinforce the barrier effect roads have on bats (Fensome & Mathews, 2016). Some bat species tolerate ALAN and often forage on insects attracted to street lights (Rydell, 2006;Polak et al., 2011;Tomassini et al., 2014;Russo & Ancillotto, 2015;Schoeman, 2016; but see Mathews et al., 2015). These species are also often tolerant of urbanization. ...
... Noticeably, B. barbastellus increased foraging activity when sites were illuminated. This is in agreement with previous work showing that when foraging or commuting this bat is not particularly sensitive to artificial light (Lacoeuilhe et al., 2014) and may occasionally hunt near street lamps (Rydell, 2006;Ancillotto et al., 2014). We speculate that B. barbastellus is more wary when drinking than when commuting or foraging, which would explain its avoidance of illuminated drinking sites. ...
Article
Artificial illumination at night (ALAN) alters many aspects of animal behaviour. Commuting and foraging bats have been found to be affected by ALAN, but no study has yet addressed the impact of lighting on drinking activity, despite its critical importance for bats. We experimentally illuminated cattle troughs used by drinking bats at four forest sites in Italy, and compared drinking activity and foraging activity under lit and dark conditions. We predicted that (1) the number of bat species and drinking events will be lower under illumination and (2) forest bat species will be more affected than edge specialists. We recorded 2549 drinking events from 12 species or species groups, most of which decreased drinking activity under illumination. The effects of ALAN on drinking were stronger than on foraging. Forest species never drank when the light was on. Edge-foraging species reduced drinking activity while also increasing foraging under lit conditions. We highlight a previously overlooked negative effect of ALAN on bats, whose implications may be locally catastrophic. Given the importance of water sites for both bat foraging and drinking, their illumination should be forbidden, appropriately mitigated or, if necessary, compensated for with the creation of alternative drinking sites.
... In general, street lamps with UV emissions attract larger moths (van Langevelde et al., 2011), whose escape behavior has been shown to be negatively impacted by light (Acharya and Fenton, 1999). Hence, these types of lamps provide effective foraging grounds which reduce the hunting effort for bats (Acharya and Fenton, 1999;Rydell, 2006). In contrast, some species might be sensitive to UV emission (Zhao et al., 2009) and likely be disturbed by it (Gorresen et al., 2015). ...
... Tree cover has been suggested to mitigate the effect of ALAN on bats (Rydell, 2006;Mathews et al., 2015). To verify this, we expected that bat species would be more active in lit areas with high tree cover compared to areas with low tree cover (i.e., trees would mitigate the negative effect of light on bat activity). ...
Article
Full-text available
With urban areas growing worldwide, so does artificial light at night (ALAN) which negatively affects many nocturnal animals, including bats. The response of bats to ALAN ranges from some opportunistic species taking advantage of insect aggregations around street lamps, particularly those emitting ultraviolet (UV) light, to others avoiding lit areas at all. Tree cover has been suggested to mitigate the negative effects of ALAN on bats by shielding areas against light scatter. Here, we investigated the effect of tree cover on the relationship between ALAN and bats in Berlin, Germany. In particular, we asked if this interaction varies with the UV light spectrum of street lamps and also across urban bat species. We expected trees next to street lamps to block ALAN, making the adjacent habitat more suitable for all species, irrespective of the wavelength spectrum of the light source. Additionally, we expected UV emitting lights next to trees to attract insects and thus, opportunistic bats. In summer 2017, we recorded bat activity at 22 green open spaces in Berlin using automated ultrasonic detectors. We analyzed bat activity patterns and landscape variables (number of street lamps with and without UV light emission, an estimate of light pollution, and tree cover density around each recording site within different spatial scales) using generalized linear mixed-effects models with a negative binomial distribution. We found a species-specific response of bats to street lamps with and without UV light, providing a more detailed picture of ALAN impacts than simply total light radiance. Moreover, we found that dense tree cover dampened the negative effect of street lamps without UV for open-space foraging bats of the genera Nyctalus, Eptesicus, and Vespertilio, yet it amplified the already existing negative or positive effect of street lamps with or without UV on Pipistrellus pipistrellus, P. pygmaeus, and Myotis spp. Our study underpins the importance of minimizing artificial light at night close to vegetation, particularly for bats adapted to spatial complexity in the environment (i.e., clutter-adapted species), and to increase dense vegetation in urban landscape to provide, besides roosting opportunities, protection against ALAN for open-space foraging bats in city landscapes.
... Diurnal and crepuscular insects that move their foraging activity into the "night light niche" (Garber, 1978) must endure cold stress (Caveney et al., 1995;Urbanski et al., 2012), while nocturnal insects that continue to forage alongside may experience reduced rates of growth due to increased competition and/or what is effectively a reduction in their spatial niche (Duarte et al., 2019). Insects avoid profitable foraging patches under illumination due to perceived (Skutelsky, 1996) or actual increases in their risk of predation by invertebrate (Heiling, 1999;Miller et al., 2017), avian (Dwyer et al., 2013, and mammalian insectivores (Rydell, 2006). For example, the reduced presence of tree (Hemideina thoracica) and cave (Rhaphidophoridae sp.) weta at artificially illuminated sites is thought to be in avoidance of geckos and other nocturnal predators (Farnworth et al., 2018). ...
... Insects that become caught in the orbit of artificial lights can be readily exploited by insectivores. This may be why predatory arthropods tend to be disproportionately represented in illuminated habitats (Davies et al., 2017(Davies et al., , 2012Eccard et al., 2018;Manfrin et al., 2017), just as insectivorous bats (Jung and Kalko, 2010;Minnaar et al., 2015;Russo et al., 2019;Rydell, 2006), rats (Yoon et al., 2010), shorebirds (Dwyer et al., 2013), geckos (Zozaya et al., 2015) and cane toads (González-Bernal et al., 2016) are often found feeding around artificial lights. Orb-web spiders prefer to build their webs near artificial lights, where they net more prey (Czaczkes et al., 2018;Heiling, 1999;Yuen and Bonebrake, 2017). ...
... Biological Conservation 241 (2020) 108259 competition and/or what is effectively a reduction in their spatial niche . Insects avoid profitable foraging patches under illumination due to perceived (Skutelsky, 1996) or actual increases in their risk of predation by invertebrate (Heiling, 1999;Miller et al., 2017), avian (Dwyer et al., 2013, and mammalian insectivores (Rydell, 2006). For example, the reduced presence of tree (Hemideina thoracica) and cave (Rhaphidophoridae sp.) weta at artificially illuminated sites is thought to be in avoidance of geckos and other nocturnal predators (Farnworth et al., 2018). ...
... Insects that become caught in the orbit of artificial lights can be readily exploited by insectivores. This may be why predatory arthropods tend to be disproportionately represented in illuminated habitats (Davies et al., , 2012Eccard et al., 2018;Manfrin et al., 2017), just as insectivorous bats (Jung and Kalko, 2010;Minnaar et al., 2015;Russo et al., 2019;Rydell, 2006), rats (Yoon et al., 2010), shorebirds (Dwyer et al., 2013), geckos (Zozaya et al., 2015) and cane toads (González-Bernal et al., 2016) are often found feeding around artificial lights. Orb-web spiders prefer to build their webs near artificial lights, where they net more prey (Czaczkes et al., 2018;Heiling, 1999;Yuen and Bonebrake, 2017). ...
Article
Insects around the world are rapidly declining. Concerns over what this loss means for food security and ecological communities have compelled a growing number of researchers to search for the key drivers behind the declines. Habitat loss, pesticide use, invasive species, and climate change all have likely played a role, but we posit here that artificial light at night (ALAN) is another important—but often overlooked—bringer of the insect apocalypse. We first discuss the history and extent of ALAN, and then present evidence that ALAN has led to insect declines through its interference with the development, movement, foraging, and reproductive success of diverse insect species, as well as its positive effect on insectivore predation. We conclude with a discussion of how artificial lights can be tuned to reduce their impact on vulnerable populations. ALAN is unique among anthropogenic habitat disturbances in that it is fairly easy to ameliorate, and leaves behind no residual effects. Greater recognition of the ways in which ALAN affects insects can help conservationists reduce or eliminate one of the major drivers of insect declines.
... The best documented effect of ALAN is the attraction of species of moths and other aerial invertebrates to lights (Fox 2013;Frank 2006); however, a recent study indicates that the presence of ALAN may also drive shifts in invertebrate community structure ). There are downstream ecological (but species-specific) effects for insectivorous predators because artificial light sources (especially in the UV range) lead to unusually high congregations of insects that change opportunistic predator movements, such as for bats (Rydell 2006;Jung & Kalko 2010;Rowse et al. 2016) and that may be advantageous for the predator but exploitatively detrimental for the insects. Ultimately, the presence of artificial light at night potentially favours species that are able to exploit the 'night-light niche', Transitions in photic environments 27 and this may have cascading effects both up and down trophic levels (Bennie et al. 2015). ...
... Guevara & Avilés (2013) suggest that exclusion of the most effective daytime predators of insects (birds) may have driven the observation of increased community body size at night, but there are numerous competing factors to be considered. Bats, for example, show preferences for larger insect prey (moths) albeit in artificially lit environments (Rydell 1992(Rydell , 2006. ...
Article
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Light represents one of the most reliable environmental cues in the biological world. In this review we focus on the evolutionary consequences to changes in organismal photic environments, with a specific focus on the class Insecta. Particular emphasis is placed on transitional forms that can be used to track the evolution from (1) diurnal to nocturnal (dim-light) or (2) surface to subterranean (aphotic) environments, as well as (3) the ecological encroachment of anthropomorphic light on nocturnal habitats (artificial light at night). We explore the influence of the light environment in an integrated manner, highlighting the connections between phenotypic adaptations (behaviour, morphology, neurology and endocrinology), molecular genetics and their combined influence on organismal fitness. We begin by outlining the current knowledge of insect photic niches and the organismal adaptations and molecular modifications that have evolved for life in those environments. We then outline concepts and guidelines for future research in the fields of natural history, ethology, neurology, morphology and particularly the advantages that high throughput sequencing provides to these aspects of investigation. Finally, we highlight that the power of such integrative science lies in its ability to make phylogenetically robust comparative assessments of evolution, ones that are grounded by empirical evidence derived from a concrete understanding of organismal natural history.
... Roosting in buildings can be beneficial to bats as urban environments provide a warm and mild microclimate (Parris and Hazell, 2005;Lausen and Barclay, 2006;Neubaum et al., 2007), accessible food resources (Rydell, 2006;Williams et al., 2006), and reduced predation pressures (Ditchkoff et al., 2006;Lausen and Barclay, 2006). Few studies on urban roost selection have been conducted on bat species worldwide. ...
... Artificial night illumination associated with cities might generate food resources for insectivorous bats (Rydell, 2006). However, the presence of artificial illumination near the roost exit had adverse effects on soprano pipistrelles (Pipistrellus pygma e us) and cave myotis (Myotis velifer) in some studies (Mann et al., 2002;Downs et al., 2003). ...
Article
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The Mexican free-tailed bat (Tadarida brasiliensis) is one of the most widely distributed bat species in the Western Hemisphere. Despite their prevalence in urban environments, limited research has been conducted to determine the features of buildings or of the surroundings that might affect the likelihood of a building being selected by Mexican free-tailed bats as a roost. Our study objectives were to improve the current understanding of Mexican free-tailed bat’s urban roosting preferences with regard to both microhabitat and macrohabitat. Between August 2010 and August 2012, we conducted acoustic surveys and emergence observations and examined 218 buildings in Waco, TX, USA. A total of 54 day-roosts for Mexican free-tailed bats was identified. At the microhabitat scale, modeling of building characteristics and opening characteristics showed that bats preferred to roost in tall and abandoned buildings. Roost exits were more likely the results of structural damage to buildings and less likely to have vegetation blocking the adjacent air space. Roost accessibility seemed to be more important than thermal condition in roost selection. At the broader macrohabitat scale, bats were more likely to roost in areas with lower income and were near tall buildings and water sources.
... During the first part of the 21 st century, the number of street lights in the UK continued to increase by 3% per annum [5] and their spectral signatures, i.e. the range of wavelengths that the lights emit, have changed [10,11]. There is currently a shift in street lighting from narrow light spectrum sources such as orange low-pressure sodium (LPS) and yellow high pressure sodium (HPS) lights to broad spectrum "white" lighting technologies such as light emitting diodes (LEDs) [9,12,13] (Fig 1). ...
... These bats share a number of traits including aerial hawking [26], foraging in open habitats [27] and emerging relatively early after sunset, which is believed to coincide with peak insect availability [26]. Eptesicus and Nyctalus species tend to fly above street lights, diving near the light cone to feed, whereas Pipistrellus species hunt in and out of the light cone [12,28]. P. pipistrellus bats spend the majority of their time in dim or dark areas [29,30], so are only likely to use lights if the benefits associated with increased foraging success outweigh the perceived risk of predation [25]. ...
Article
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We used a before-after-control-impact paired design to examine the effects of a switch from low-pressure sodium (LPS) to light emitting diode (LED) street lights on bat activity at twelve sites across southern England. LED lights produce broad spectrum 'white' light compared to LPS street lights that emit narrow spectrum, orange light. These spectral differences could influence the abundance of insects at street lights and thereby the activity of the bats that prey on them. Most of the bats flying around the LPS lights were aerial-hawking species, and the species composition of bats remained the same after the switch-over to LED. We found that the switch-over from LPS to LED street lights did not affect the activity (number of bat passes), or the proportion of passes containing feeding buzzes, of those bat species typically found in close proximity to street lights in suburban environments in Britain. This is encouraging from a conservation perspective as many existing street lights are being, or have been, switched to LED before the ecological consequences have been assessed. However, lighting of all spectra studied to date generally has a negative impact on several slow-flying bat species, and LED lights are rarely frequented by these 'light-intolerant' bat species.
... Por otra parte, el efecto del desarrollo urbano en áreas cercanas a remanentes de bosques sobre los murciélagos insectívoros parece depender de la especie (Jung & Kalko, 2010). Así, algunos murciélagos, parecen tolerar las urbanizaciones y aprovechan la presencia de luces artificiales, que atraen insectos, como sitios de forrajeo, aunque la rentabilidad parece ser mejor alrededor de las lámparas de luz blanca, que alrededor de las de luz amarilla-naranja (Jung & Kalko, 2010;Rydell, 2006); sin embargo, los murciélagos también pueden ser perjudicados por las áreas urbanizadas, que vienen asociadas con la construcción de vías y éstas pueden ser agentes de mortalidad para los murciélagos insectívoros que sufren el riesgo de estrellarse con los vehículos (Lodé, 2000;Russell et al. 2009). Por lo tanto, el desarrollo urbanístico puede, potencialmente, tener efectos positivos y negativos sobre las poblaciones de murciélagos insectívoros. ...
... Adicionalmente, los lugares con lámparas: en Torca, en Las Mercedes y en la U.D.C.A lograron niveles de forrajeo mayores, a los registrados en los otros lugares. Así, los resultados también indican que los puntos de observación con iluminación artificial son usados como parches de forrajeo por parte de los murciélagos, como ocurre en otras áreas urbanas y semiurbanas del neotrópico Cómo ya se mencionó, las lámparas, en particular las de luz blanca, se convierten en parches alimentarios, valiosos para los murciélagos insectívoros, en ambientes urbanos o semiurbanos, dado que atraen y acumulan insectos a su alrededor y actúan mejor cuando están rodeadas de ambientes naturales o similares (Gaisler et al. 1998;Rydell, 2006). Así, las lámparas son aprovechadas en el norte de Figura 3. A. Actividad de forrajeo de los murciélagos insectívoros (fases de terminales/5 min), alrededor de un edificio con lámparas de luz blanca en la U.D.C.A. Las barras son promedios ± error estándar; barras con letras diferentes indican diferencias significativas (Prueba de Bonferroni, p<0,05). ...
Article
Full-text available
RESUMEN El borde norte de la Bogotá, Colombia, es un mosaico de ecosistemas transformados (urbanizaciones, cultivos, pastizales) y ecosistemas naturales (bosques andinos, humedales). En la actualidad, no se conoce cómo dicha heterogeneidad espacial afecta la ecología de las especies silvestres que sobreviven en la ciudad. Se propuso, que la heterogeneidad del paisaje del norte de Bogotá afecta el patrón temporal de actividad de los murciélagos insectívoros y su uso de hábitat. Se esperaba encontrar diferentes patrones de actividad temporal y de uso en sitios con diferentes grados de alteración humana. Se hicieron inspecciones acústicas en sitios con remanentes naturales, sitios con iluminación artificial y cercana a vías para automóviles. Los murciélagos insectívoros se registraron, tanto en áreas con remanentes naturales como intervenidas a lo largo del norte de Bogotá. La actividad de los murciélagos insectívoros cerca a vías importantes aumentó al avanzar la noche, mientras que en sitios sin vías principales fue en las primeras horas de la noche. Esto sugiere, que los murciélagos evitan zonas con alto flujo vehicular y estas vías reducen la disponibilidad de hábitats para los murciélagos insectívoros, al menos, en las primeras horas de la noche. Los sitios con iluminación artificial concentraron mayor actividad de forrajeo que sitios sin ella. La iluminación artificial parece beneficiar a algunos murciélagos, que encuentran allí parches, donde se acumulan sus presas potenciales y, es posible, que dicha iluminación se pueda usar en áreas agrícolas de la ciudad, para el control de poblaciones plaga, con la ayuda de los murciélagos.
... En los ambientes tropicales la biomasa total anual de fruta es mayor a la de otros recursos alimentarios que son utilizados por los murciélagos, como néctar e insectos, razón por la cual en ambientes naturales la densidad de murciélagos frugívoros tiende a ser mayor que la de murciélagos nectarívoros, y estas a su vez mayores que las de insectívoros (CARRERA, 2003;HUNTER et al., 1992). Sin embargo, los procesos de urbanización generan cambios en la estructura de los recursos alimentarios (GRIMM et al., 2008) al reducir la cobertura vegetal y aumentar la cantidad de insectos por la presencia de fuentes de iluminación permanentes (RYDELL, 2006;RYDELL & BAGRE, 1996;THREFALL et al.;. Por este motivo, en ambientes urbanos la tendencia general es hacia la disminución de especies frugívoras y el aumento en el número de especies insectívoras (GAISLER et al., 1998;MCINTYRE et al., 2000;OSPINA-REINA, 2008;THREFALL et al., 2012). ...
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Between October 2006 and September 2007 bats were caught using mist nets in the Melendez Campus at Universidad delValle in order to describe the composition and assemblage structure of chiropterans. During 24 nights of sampling (8,640 mist nest-hours) nine species were recorded belonging to five families (Emballonuridae, Molossidae, Vespertilionidae, Noctilionidae, Phyllostomidae). Artibeus lituratus was the most abundant species accounting for 66% of all captures, followed by Phyllostomus discolor (13.6%) and Glossophaga soricina (7.8%). Frugivorous were the category with the largest number of species and the most abundant with 67.8% recorded catches. Results of this investigation confirm that the Melendez campus at Universidad del Valle constitutes an important reservoir for chiropteran diversity that live in the urban area due to its vegetative cover, permanent presence of water bodies and permanent offer of food.
... En los ambientes tropicales la biomasa total anual de fruta es mayor a la de otros recursos alimentarios que son utilizados por los murciélagos, como néctar e insectos, razón por la cual en ambientes naturales la densidad de murciélagos frugívoros tiende a ser mayor que la de murciélagos nectarívoros, y estas a su vez mayores que las de insectívoros (CARRERA, 2003;HUNTER et al., 1992). Sin embargo, los procesos de urbanización generan cambios en la estructura de los recursos alimentarios (GRIMM et al., 2008) al reducir la cobertura vegetal y aumentar la cantidad de insectos por la presencia de fuentes de iluminación permanentes (RYDELL, 2006;RYDELL & BAGRE, 1996;THREFALL et al.;. Por este motivo, en ambientes urbanos la tendencia general es hacia la disminución de especies frugívoras y el aumento en el número de especies insectívoras (GAISLER et al., 1998;MCINTYRE et al., 2000;OSPINA-REINA, 2008;THREFALL et al., 2012). ...
Article
Full-text available
Between October 2006 and September 2007 bats were caught using mist nets in the Me-lendez Campus at Universidad delValle in order to describe the composition and assemblage structure of chiropterans. During 24 nights of sampling (8,640 mist nest-hours) nine species were recorded belonging to five families (Emballonuridae, Molossidae, Vespertilionidae, Noctilionidae, Phyllostomidae). Artibeus lituratus was the most abundant species accounting for 66% of all captures, followed by Phyllostomus discolor (13.6%) and Glossophaga soricina (7.8%). Frugivorous were the category with the largest number of species and the most abundant with 67.8% recorded catches. Results of this investigation confirm that the Melendez campus at Universidad del Valle constitutes an important reservoir for chiropteran diversity that live in the urban area due to its vegetative cover, permanent presence of water bodies and permanent offer of food.
... Studies show that some insectivore species are specialized in prey during the flight in open areas with high concentration of insects and no obstacles, or in areas where insects are attracted by artificial light in urban regions (Rydell 2006, Lacoeuilhe et al. 2014. Bats can detect the sound of motors and avoid to use the ways of higher traffic (Zurcher et al. 2010), and consequently, use those places as part of their route of daily foraging area (Frank 1988, Blake et al. 1994, Svensson & Rydell 1998. ...
Article
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The most studied impact on road ecology is roadkill, however, there is little information about the relations between highways and specific groups like bats. This study intended to identify the species of bats roadkilled and to evaluate the existence of temporal fluctuation between the roadkill rates, specific stretches of the road with higher rates, and characteristics of the road/landscape that may influence those rates. We encountered at least nine bat species among 65 roadkills (most Phyllostomidae), which comprise a subgroup of the local fauna that presents ecologic features that make them susceptible to being hit, especially Artibeus lituratus. The medium roadkill rate was of 0.01 individuals/km/day of monitoring, and there was no significant temporal variation. We identified five hotspots through special 2D HotSpot Identification Analysis. The selection of theoretical models through Generalized Linear Models showed that roadkill occurrence has a positive relation with vehicular traffic and negative relation with presence of marginal pasture and forests. As the major part of records was of species that are tolerant to human-disturbances, the increase in traffic consequently affected a higher number of bats capable to explore the area occupied by the road. The presence of native forest close to the road can lead to a decrease of animals hit by vehicles, once it offers more resources and favorable habitats, which reduces the need for bats to cross the roads for foraging. On the other hand, many species that necessarily depend on areas sheltered by trees for shelter, and do not possess the ability to fly long distances do not occur in open areas such as pastures. In this context, we suggest that the main measure of mitigation regard bat species would be the traffic control through speed limit, especially on the roadkill hotspots areas.
... Because birds are consuming prey that will eventually experience reproductive and adult mortality associated with the polarized light trap, this scenario appears to represent a clear case of compensatory mortality (Errington 1946). The predator-prey interactions observed by Robertson et al. (2010) are qualitatively similar to the hunting of insects attracted to streetlamps at night by anuran amphibians (Buchanan 2006), reptiles (Perry and Fisher 2006), birds (Eisenbeis 2006), bats (Rydell 2006) and spiders (Frank 2006), a well-known secondary effect of conventional (nonpolarized) ecological light pollution. ...
Chapter
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In the last decade it has been recognized that the artificial polarization of light can have uniquely disruptive effects on animals capable of seeing it and has led to the identification of polarized light pollution (PLP) as a new kind of ecological photopollution. In this chapter we review some typical examples for PLP and the resulting polarized ecological traps. All such polarized-light-polluting artificial surfaces are characterized by strongly and horizontally polarized reflected light attracting positively polarotactic aquatic insects, the larvae of which develop in water or mud, such as aquatic beetles (Coleoptera), water bugs (Heteroptera), dragonflies (Odonata), mayflies (Ephemeroptera), caddisflies (Trichoptera), stoneflies (Plecoptera) and tabanid flies (Tabanidae), for example. We survey here the PLP of asphalt surfaces, solar panels, agricultural black plastic sheets, glass surfaces, black gravestones and the paintwork of black-, red- and dark-coloured cars. We show how the maladaptive attractiveness (PLP) of certain artificial surfaces to polarotactic insects can be reduced or eliminated. We consider how birds, spiders and bats exploit polarotactic insects trapped by different sources of PLP. We deal with the phenomenon that the vertically polarized mirror image of bridges seen at the river surface can deceive swarming polarotactic mayflies, which is an atypical kind of PLP. We explain why strongly polarizing black burnt-up stubble fields do not attract aquatic insects, which is an example for a horizontal, black polarizing surface that does not induce PLP and thus is an exception proving the rule. Finally, we show that phototaxis and polarotaxis together have a more harmful effect on the dispersal flight of night-active aquatic insects than they would have separately. This provides experimental evidence for the synergistic interaction of phototaxis and polarotaxis in these insects.
... Ces paramètres affectent différemment les espèces, cependant, les variations de vitesse de vent constituent un paramètre influençant fortement l'activité des chauves-souris (Baerwald et Barclay, 2011 ;Behr et al., 2011). Certains auteurs (Rydell et al., 2006 ;Arnett et al., 2006) Depuis, des systèmes basés sur une élévation du seuil de vitesse de vent nécessaire au démarrage des éoliennes ont été testés au Etats-Unis (Arnett et Schirmacher, 2009 ;Baerwald et al., 2009). Le passage d'une vitesse de vent de démarrage de 3,5 m.s -1 à 5,5 m.s -1 permettrait de réduire la mortalité de 60 à 80 %. ...
... However, increased activity around lighting sources may increase risk of predation (Stone et al. 2009). Approximately 75% of the 450,000 streetlights in Melbourne are mercury vapor (Equipment Energy Efficiency Program 2011) which are known to attract high numbers of insects (Rydell 2006). The predominantly negative effect of artificial light on most bat species in our study suggests that lights are having damaging effects on bat habitats, although it is not clear whether other types of lighting would be more benign. ...
Article
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Wetlands support unique biota and provide important ecosystem services. These services are highly threatened due to the rate of loss and relative rarity of wetlands in most landscapes, an issue that is exacerbated in highly modified urban environments. Despite this, critical ecological knowledge is currently lacking for many wetland-dependent taxa, such as insectivorous bats, which can persist in urban areas if their habitats are managed appropriately. Here, we use a novel paired landscape approach to investigate the role of wetlands in urban bat conservation and examine local and landscape factors driving bat species richness and activity. We acoustically monitored bat activity at 58 urban wetlands and 35 nonwetland sites (ecologically similar sites without free-standing water) in the greater Melbourne area, southeastern Australia. We analyzed bat species richness and activity patterns using generalized linear mixed-effects models. We found that the presence of water in urban Melbourne was an important driver of bat species richness and activity at a landscape scale. Increasing distance to bushland and increasing levels of heavy metal pollution within the waterbody also negatively influenced bat richness and individual species activity. Areas with high levels of artificial night light had reduced bat species richness, and reduced activity for all species except those adapted to urban areas, such as the White-striped free-tailed bat (Austronomus australis). Increased surrounding tree cover and wetland size had a positive effect on bat species richness. Our findings indicate that wetlands form critical habitats for insectivorous bats in urban environments. Large, unlit, and unpolluted wetlands flanked by high tree cover in close proximity to bushland contribute most to the richness of the bat community. Our findings clarify the role of wetlands for insectivorous bats in urban areas and will also allow for the preservation, construction, and management of wetlands that maximize conservation outcomes for urban bats and possibly other wetland-dependent and nocturnal fauna.
... Similarly, despite the presence of street lit areas within the home range of Rhinolophus ferrumequinum, they were never used by this spe cies, which is classified as photophobic (Jones and Morton, 1992;Day et al., 2015). On the other hand, relatively fast flying bats that typically forage in open spaces and use long range echolocation pulses, such as Eptesicus, Nyctalus and Pipistrellus species, could take advantage of street lights (Rydell, 1991(Rydell, , 1992(Rydell, , 2006Blake et al., 1994). For such light-tolerant bat species, artificial lights create an illuminated night niche that acts as a very effective artificial feeding resource (Stone et al., 2015) because of the higher insect density (moths in particular) attracted to such lights (Eisenbeis et al., 2006;van Langevelde et al., 2011). ...
Article
Rapid range expansion of Kuhl’s pipistrelle (Pipistrellus kuhlii) has been observed throughout Europe, and in addition to its natural habitats of temperate grasslands and agricultural areas, the species is common in city centres, where it roosts in human-made structures. It has been suggested that the flexibility of this species in regard to different human-induced changes, such as climate change and urbanization, is responsible for the apparent range shift. Although P. kuhlii exhibits one of the highest degrees of synanthropy among bat species in Europe, its ecology has thus far not been thoroughly studied. This study aims to describe its foraging and roosting selection in Central Europe (eastern Slovakia), where the northernmost maternity colony of P. kuhlii roosts in human settlements. Radio-tracking was conducted during the pre-parturition and post-lactation periods. We identified six artificial roosts within the study area that were interlinked, with bats switching between them. Ten individuals were used for modelling foraging-habitat utilization, which revealed that bats were highly selective. The only habitat type that bats clearly preferred, regardless of season, was an urban illuminated area close to a river. Only slight avoidance — of open areas — was observed during the pre-parturition period.
... Increasingly, artificial light has come under investigation for its potential to have negative ecological impacts (Longcore & Rich 2004;H€ olker et al. 2010;Gaston, Visser & H€ olker 2015). Light at night is suspected to have negative consequences for insects in particular (Frank 1988;Eisenbeis & H€ anel 2009;Perkin, H€ olker & Tockner 2014), through wasted time and energy, distraction from normal mating and feeding behaviour (Frank 1988;van Geffen et al. 2015b), death through predation (Rydell 2006) and direct burning or exhaustion (Eisenbeis & H€ anel 2009). The reaction of insects to light depends on the intensity and wavelength spectrum of the light source (van Langevelde et al. 2011). ...
Article
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Artificial lights have become an integral and welcome part of our urban and peri-urban environments. However, recent research has highlighted the potentially negative ecological consequences of ubiquitous artificial light. In particular, insects, especially moths, are expected to be negatively impacted by the presence of artificial lights. Previous research with light traps has shown a male-biased attraction to light in moths. In this study, we sought to determine whether street lights could limit moth dispersal and whether there was any sex bias in attraction to light. More specifically, we aimed to determine sex-specific attraction radii for moths to street lights. We tested these hypotheses by collecting moths for 2 years at an experimental set-up. To estimate the attraction radii, we developed a Markov model and related it to the acquired data. Utilizing multinomial statistics, we found that attraction rates to lights in the middle of the matrix were substantially lower than predicted by the null hypothesis of equal attraction level (0·44 times). With the Markov model, we estimated that a corner light was 2·77 times more attractive than a wing light with an equivalentre attraction radius of c. 23 m around each light. We found neither sexual differences in the attraction rate nor in the attraction radius of males and females. Since we captured three times more males than females, we conclude that sex ratios are representative of operational sex ratios or of different flight activities. These results provide evidence for street lights to limit moth dispersal, and that they seem to act equally on male and female moths. Consequently, public lighting might divide a suitable landscape into many small habitats. Therefore, it is reasonable to assume (i) that public lighting near hedges and bushes or field margins reduces the quality of these important habitat structures and (ii) that public lighting may affect moth movement between patches.
... Probablemente los parques pequeños no posean la complejidad vegetal necesaria que incrementa la riqueza y abundancia de insectos, por lo que no serían utilizados como sitios de forrajeo por algunas especies de vespertiliónidos. Ávila-Flores y Fenton (2005) sugieren que la ausencia de algunos miembros de esta familia puede deberse a que la ciudad representa un área hostil cuyas zonas iluminadas tienden a ser evitadas como un mecanismo para reducir el riesgo de depredación; sin embargo para otras especies, son sitios favorables de alimentación (Rydell, 2006). Algunas especies pequeñas con frecuencias altas de ecolocalización suelen asociarse negativamente con sitios urbanos, teniendo mayor actividad en áreas con mayor cobertura vegetal (Threlfall et al., 2011). ...
Article
We evaluated habitat use of insectivorous bats in five urban parks in San José, Costa Rica. Three sessions of acoustic monitoring were carried out for three nights, between 18:00-19:30 h. A total of 457 recordings (402/large parks, 44/small parks, 11/controls) were obtained. Large parks were sites of greater richness and activity than those lacking vegetation (controls). There was no significant difference in the number of species between small and large parks; however, the park use differed significantly between species. Parks cannot replace natural conditions but are important for maintaining the remaining diversity of bats in urban sites.
... On the other hand, there are many examples of the regular use by bats of street lighting in order to forage (e.g. Rydell, 2006), and despite examples of the negative impact of road development on bat populations, some bat species regularly use human-transformed habitats. Some of these species may now be regarded as synanthropic and regularly use buildings for hibernation, daily rest, and reproduction (Hale et al., 2012). ...
Article
The most negative impacts of roads on bats are increased mortality caused by collisions with vehicles, noise pollution reducing both communication and foraging, and barriers to movement. To test the effect of roads and traffic on the occurrence and foraging habits of bats in forested landscapes in western Poland we compared 53 sites located along local asphalt roads of low to medium traffic volume with paired reference sites on unsurfaced forest roads. Acoustical monitoring systems with Anabat detectors were used at night to detect bats at all sites. Overall, we found a strongly significant preference of bats for local asphalt roads; 640 bat passes were recorded at asphalt roads but only 271 at reference sites. Furthermore, significantly more bat taxa, longer activity and a greater frequency of feeding buzzes (calls used during foraging) were also recorded at asphalt roads. However, significant benefits were not shown for all species. This study clearly shows that local asphalt roads in forested landscapes are important foraging areas for several bat species.
... Reith (1982) found that bats tend to fly lower and in tree shadows under full moon, while Hecker & Brigham (1999) found that bats flew higher when the moon was fuller. This inconsistency might be due to differing foraging strategies of different bat species (compare Rydell, 2006), yet species in both studies belong to the same foraging guild of aerial insectivores. Our finding of a decrease in flight height under artificial lighting is in agreement with Reith (1982), yet levels of ambient moonlight and artificial lighting might not be fully equivalent. ...
Article
Human habitation in deserts can create rich novel resources that may be used by native desert species. However, at night such resources may lose attractiveness when they are in artificially lit areas. For bats, attraction to such manmade habitats might be species specific. In an isolated village in the Negev desert that is known for its high bat activity we investigated the effects of artificial lighting on flight behaviour of two aerial insectivorous bat species: Pipistrellus kuhlii, a non-desert synanthropic bat, common in urban environments and Eptesicus bottae, a desert-dwelling species. Using an acoustic tracking system we reconstructed flight trajectories for bats that flew under artificial lights [Light treatment (L)] versus in natural darkness [Dark treatment (D)]. Under L both P. kuhlii and E. bottae flew significantly faster than under D. Under L, P. kuhlii also flew at significantly lower altitude (i.e. away from a floodlight) than under D. Whereas P. kuhlii foraged both in L and D, E. bottae only foraged in D. In L, activity of E. bottae decreased and it merely transited the illuminated area at commuting rather than foraging speed. Thus, under artificially lighted conditions the non-desert synanthropic species may have a competitive advantage over the native desert species and may outcompete it for aerial insect prey. Controlling light pollution in deserts and keeping important foraging sites unlit may reduce the synanthropic species' competitive advantage over native desert bats.
... Because birds are consuming prey that will eventually experience reproductive and adult mortality associated with the polarized light trap, this scenario appears to represent a clear case of compensatory mortality (Errington 1946). The predator-prey interactions observed by Robertson et al. (2010) are qualitatively similar to the hunting of insects attracted to streetlamps at night by anuran amphibians (Buchanan 2006), reptiles (Perry and Fisher 2006), birds (Eisenbeis 2006), bats (Rydell 2006) and spiders (Frank 2006), a well-known secondary effect of conventional (nonpolarized) ecological light pollution. ...
... LEDs do not induce phototaxis to the same degree as other light sources, especially mercury vapour (Eisenbeis & Eick, 2011;Huemer, Kühtreiber, & Tarmann, 2010), likely because LEDs do not produce light in the lower UV spectrum . Other forms of light which lack UV light, such as high pressure sodium, also attract fewer insects (Rydell, 2005). Light sources with lower insect abundance have significantly less bat activity (Blake, Hutson, Racey, Rydell, & Speakman, 1994); in fact, bat activity can change by as much as an order of magnitude depending on lighting technology (Rydell, 1992). ...
Article
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Light pollution has been increasing around the globe and threatens to disturb natural rhythms of wildlife species. Artificial light impacts the behaviour of insectivorous bats in numerous ways, including foraging behaviour, which may in turn lead to altered prey selection. 2.In a manipulative field experiment, we collected faecal samples from six species of insectivorous bats in naturally dark and artificially lit conditions, and identified prey items using molecular methods to investigate effects of light pollution on prey selection. 3.Proportional differences of identified prey were not consistent and appeared to be species specific. Red bats, little brown bats, and gray bats exhibited expected increases in moths at lit sites. Beetle-specialist big brown bats had a sizeable increase in beetle consumption around lights, while tri-colored bats and evening bats showed little change in moth consumption between experimental conditions. Dietary overlap was high between experimental conditions within each species, and dietary breadth only changed significantly between experimental conditions in one species, the little brown bat. 4.Policy implications. Our results, building on others, demonstrate that bat-insect interactions may be more nuanced than the common assertion that moth consumption increases around lights. They highlight the need for a greater mechanistic understanding of bat-light interactions to predict which species will be most affected by light pollution. Given differences in bat and insect communities, we advocate biologists, land stewards, and civil planners work collaboratively to determine lighting solutions that minimize changes in foraging behaviour of species in the local bat community. Such efforts may allow stakeholders to more effectively craft management strategies to minimize unnatural shifts in prey selection caused by artificial lights. This article is protected by copyright. All rights reserved.
... In contrast, the visual capability of bats is primarily rod dominated, and species response to road lighting varies by level of illumination and area affected (Lesson 18.5). Foraging opportunities for bats can be enhanced due to insect attraction to light (Eisenbeis 2006;Lesson 34.3), but increased competition with other bat species and avoidance of lighting can also pose negative effects (Rydell 2006;Zurcher et al. 2010;Stone et al. 2012). Bats attracted to road lighting are also susceptible to vehicle collisions (Zurcher et al. 2010;Chapter 34). ...
Chapter
Natural light plays an integral role in biological systems, one that can be disrupted by the intrusion of other light sources. Specifically, artificial lighting, including road lighting, poses negative effects on plant and animal physiology, animal behaviour and predation rates. These effects are cumulative as multiple, artificial light sources contribute. 1 Light functions as a natural stimulus. 2 Metrics used to quantify artificially produced light are generally not biologically relevant. 3 Species response to artificial light varies by visual system. 4 Light emitted varies relative to the type of lighting technology. 5 Planning for road lighting must include zoning relative to light levels and light-fixture placement. 6 Mitigating the negative effects of road lighting requires research collaboration. Negative effects of artificial lighting, including road lighting, are manageable. By better understanding the ecosystems through which roads pass and how light affects resident organisms, we can adapt lighting fixtures, fixture design and zoning to minimise site-specific effects, as well as contributions to cumulative light pollution.
... Artificial light also provokes a 'dazzling effect': many insects become immobilized when approaching a lamp and rest on the ground or in vegetation, becoming easy prey (Eisenbeis & H€ anel, 2009). Moths become easier for bats to catch at lights (reviewed by Rowse, Lewanzik, Stone, Harris, & Jones, 2016); the lights (simulating diurnal conditions) appear to switch off the predator evasion responses of moths to ultrasound stimuli, while the lack of protective vegetation underneath lighting reduces the effect of their evasive flights (Rydell, 2006). For example, in rural residential landscapes in Canada, big brown bats, Eptesicus fuscus, show significantly greater feeding activity around streetlighting (Geggie & Fenton, 1985). ...
Article
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Novel ecosystems (‘emerging ecosystems’) result when species occur in combinations and relative abundances that have not occurred previously within a given biome, due to deliberate or inadvertent human agency. Humans have changed the environment through disturbance, physical structures or additional resources. Many vertebrate predators inhabit cities, towns and other places that humans have built or altered, and make use of these anthropogenic niches. These predators range in size from bats swarming around lamp posts, to leopards stalking domestic animals in the heart of cities. In this essay, we describe four scenarios where predators opportunistically make use of anthropogenic niches. First, humans are surrounded by animals, including synanthropic rodents and birds, livestock and pets, that can be novel prey for opportunistic predators. Second, feeding on prey concentrations created through anthropogenic niches increases their hunting efficiency, by reducing both search and commute times. Third, anthropogenic environments create novel situations such as thermals and artificial lighting that advantage some predators, increasing their capture success. Finally, many predators have developed novel hunting strategies to make the most of opportunities in anthropogenic environments that can lead to greater hunting success. We give examples of these four scenarios and have developed a conceptual model that captures the common mechanisms relevant to each, with predictions for how these can be explored further in future studies. Predators exploiting anthropogenic niches can experience greater ease of hunting, decreased search effort and/or increased capture success. Consequently, these animals experience many physiological and reproductive benefits over conspecifics that do not make similar use of anthropogenic niches, ultimately benefitting from living alongside humans.
... Some species, for example, require the dark to forage successfully (Rotics et al., 2011) while others use naturally occurring light, like the moon, as a cue for key behaviors like finding appropriate habitat or orientation during flight (Frank, 1988;Tuxbury & Salmon, 2005;Kriska et al., 2009). Although light pollution is relatively well-studied for some vertebrates, such as bats, birds, turtles, and humans (Rydell, 1992(Rydell, , 2006Rich & Longcore, 2006;Navara & Nelson, 2007;Jung & Kalko, 2010;Kempenaers et al., 2010;Santos et al., 2010;Falchi et al., 2011;Bedrosian & Nelson, 2013;Davies et al., 2013;Gaston et al., 2013;Kamrowski et al., 2014;Da Silva et al., 2015;Hale et al., 2015 and references therein), the impacts of artificial lighting have been explored for few invertebrate systems (Rich & Longcore, 2006; but see Davies et al., 2012Davies et al., , 2013Bennie et al., 2015) and not at all for plant communities that are surrounded by urban areas (Neil & Wu, 2006). Furthermore, most studies of light pollution focus on individual species and lack a community perspective . ...
Article
Light pollution is a global disturbance with resounding impacts on a wide variety of organisms, but our understanding of these impacts is restricted to relatively few higher vertebrate species. We tested the direct effects of light pollution on herbivore performance as well as indirect effects mediated by host plant quality. We found that artificial light from streetlights alters plant toughness. Additionally, we found evidence of both direct and indirect effects of light pollution on the performance of an herbivorous insect, which indicates that streetlights can have cascading impacts on multiple trophic levels. Our novel findings suggest that light pollution can alter plant-insect interactions and thus may have important community-wide consequences.
... It has been shown that artificial light at night can alter predator-prey interactions (Gaston et al. 2015;Longcore and Rich 2004;Navara and Nelson 2007). For example, many species of bats can efficiently forage at night near artificial light sources that attract insects (Minnaar et al. 2015;Patriarca and Debernardi 2010;Rydell 2006). Although the number of studies on light pollution is increasing from year to year, little is known about aquatic ecosystems, thus they require particular attention (Brüning et al. 2011;Moore et al.2001;Perkin et al. 2011;Perkin et al. 2014). ...
Article
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Artificial light at night may affect mortality risk in prey from visually oriented predators because the effect of the artificial light spectrum may differ for a predator’s visual prey detection and for prey evasiveness. To test this, we conducted two types of experiment. First, we assessed the reaction distance and swimming speed of juvenile rudd (Scardinius erythrophthalmus) allowed to forage on juvenile Daphnia pulex × pulicaria under three artificial light sources: halogen, high pressure sodium (HPS), and metal halide bulbs, at the same light intensity. Second, we assessed the evasiveness of D. pulex × pulicaria under the same artificial light sources and in darkness (as a control), in the presence and absence of chemical information on predation risk (kairomones) of juvenile rudd. We found that while both reaction distance and swimming speed of fish was greater under halogen compared to HPS, and similar under metal halide light compared to halogen and HPS, the evasiveness of Daphnia was greater under halogen and HPS-generated light than under metal halide light. The results suggest a possible mismatch of Daphnia’s behavioural response under metal halide light to predicted predation risk, and thus a possible threat to predator–prey balance in a lake ecosystem.
... The second highest detection of P. davisoni in our study was recorded within urban landscapes, suggesting that this elusive bat species may be a city dweller as occurring with other species of molossid bats that appear to benefit from urbanization and selectively forage in anthropized areas (Scanlon and Petit, 2008;Taylor et al., 2019;Threlfall et al., 2011;Voigt et al., 2016). Streetlights in urban areas may benefit bats by fostering a high concentration of insects (Avila-Flores and Brock Fenton, 2005;Eisenbeis, 2006;Jung and Kalko, 2010;Rydell, 2006). Likewise, bats have been observed using buildings in urban areas as roosting and foraging sites, temporary shelters, and for reproduction, and hibernation (Hourigan et al., 2006;Rodríguez-Aguilar et al., 2017;Voigt et al., 2016). ...
Article
Davison’s Mastiff Bat Promops davisoni is a poorly studied species, only present in Ecuador, Peru and more recently in Chile, where its known geographic distribution is supported by very few records from the extreme north of the country. Using ultrasonic recordings, we reported new records of P. davisoni in northern Chile, extending its distribution range ca. 60 km southward to the Chaca and Camarones valleys in the province of Arica. Additionally, using Species Distribution Models, we predicted its potential distribution in the north of the country based on similar suitable habitats. The high number of recordings obtained in our study suggest a wide distribution and relative abundance of P. davisoni in the coastal valleys of the Arica province and surrounding urban areas, with a remarkable habitat diversity for populations of this species. In addition, our potential distribution models suggest its presence in other arid environments within the Atacama Desert. These data provide additional information on the current and potential distribution of P. davisoni and can be useful for further studies to better understand the biology and population dynamics of the species, as well as the design of conservation and management strategies.
... ALAN has been shown to broadly affect free-flying bats in two ways. First, fastflying species forgo their usual foraging areas to feed on the insects attracted to lights, potentially drawing them into ecological traps (Rydell, 2006;Russo and Ancillotto, 2015). Second, slow-flying species avoid lit areas completely, likely for fear of owl predation (Stone et al., 2012). ...
Article
Free-flying bats are highly affected by artificial night lighting, causing individuals to either 1) gather in unnaturally high densities around the light sources to exploit insects, or 2) travel increased distances to avoid light exposure. Similarly, nocturnal insects are disproportionately attracted to night lighting, trapping them until they die of exhaustion. The advent of new lighting technology which may decrease the impacts of night lighting on bats and insects by primarily producing light at wavelengths these animals are not sensitive to (i.e. in the red portion of the spectrum) is promising, however no studies have shown this at a large scale, and not in North America. Similarly, many studies on the effects of lights on bats, in general, have been on European species, and thus our overall understanding of how North American species are affected is low. Grand Teton National Park, Wyoming, provides an excellent natural system to study the effects of lights on bat behavior, as well as to test possible mitigation methods, as the park supports a large community of over a dozen species, as well as sizeable human infrastructure that generates night light. From June through September, 2019, we undertook a large-scale, blocked experiment examining bat activity and space use in Colter Bay Village under both traditional street-lighting, as well as new “bat friendly” street lighting. Using both passive echolocation records and radiotelemetry, we collected data that will allow us to examine the ability of red LED streetlights to mitigate artificial light’s negative impacts on bats and insects. Featured photo from figure 2 in report.
... Various factors may account for the higher bat activity observed near roads in open habitats. Insects may be attracted to road verges because of the change in microclimate and the presence of artificial light (Rydell 2006;Stone et al. 2015), including lights from cars (Zortéa and Aguiar 2001). Moreover, higher temperatures and light reflection of asphalt also may attract insects to roads (Muñoz et al. 2015), increasing resource availability for insectivores. ...
Article
Roads have direct and indirect impacts on animals present in the surrounding habitats. Bats have extensive foraging ranges which may include roads, and are therefore particularly affected by them. This study aimed to analyze the effects of roads on bat activity and diversity in the Brazilian savanna. Nine transects were established in protected areas in central Brazil with sampling points at 0, 500, 1,000, and 1,500 m away from roads. At each point, we recorded bat echolocation for 12 h and evaluated the influence of road type and distance from the road on bat activity, diversity, and foraging effort. Season, normalized difference vegetation index (NDVI), and distance to water also were included in the models. We found that species richness in the dry season and activity of open space insectivores were significantly higher on road verges than on areas farther from roads, while foraging effort and activity of edge space insectivores were only influenced by season. The activity of edge space insectivores also increased significantly with increasing distance to water during the rainy season. We suggest that bat individuals do not forage near roads, but rather use them as flyways or cross them to forage in sites outside the protected areas, which can increase the risk of collision with vehicles.
... The anti-phototactic behavior may bring these bats closer to potential risks of collision with vehicles when they forage in areas or roost in caves close to roads in dark environments. On the other hand, bats that exhibit positive phototaxis might be attracted by swarming insects surrounding lights [82,83]. For example, P. arbramus, a non-cave roosting bat and the most frequently recorded victim species in this study, is often observed hunting insects near streetlights (JCCH personal observation). ...
Article
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The expansion of roads has threatened wildlife populations by driving casualties due to vehicle collisions. However, the ecological drivers of wildlife roadkills are not yet fully explored. We investigated the strength of landscape features and ecomorphological traits in determining spatial patterns of bat roadkills in Taiwan. In total, 661 roadkills that belonged to 20 bat species were acquired by citizen scientists between 2011 and 2019. The number and species richness of victim bats declined with increasing elevations with varying species compositions. Elevation and artificial light had significantly negative effects on the occurrence of roadkill, whereas protected area and its interaction with elevation had positive effects. Ordination analyses showed that roadkills were driven by different ecomorphological traits and landscape features. At low elevations, road casualties were associated with an aerial hawking hunting strategy. At higher elevations, roadkills were associated with higher elevational distribution. Roadkills of non-cave bats were associated with brighter environments, suggesting that bats might be exposed to higher risk when hunting insects near artificial light. Our findings suggest that management agencies shall consider both species traits and landscape features when planning impact assessments and mitigation practices of roadkills for bats and probably other wildlife, particularly when long environmental gradients are covered.
... Burns et al. (2016) found a lack of evidence for the impact of light pollution on bat populations; however, recently the number of studies assessing the impacts of artificial light at night (ALAN) on bats has increased. Evidence suggests that some species, such as Pipistrellus pipistrellus and Pipistrellus pygmaeus, exploit the insects attracted to the light (Rydell 2006, Lacoeuilhe et al. 2014, Zeale et al. 2018. However, species that prefer low-light conditions for emergence or foraging, such as Rhinolophus ferrumequinum, Rhinolohus hipposideros, Myotis emarginatus, Myotis oxygnathus, and other Myotis spp., are adversely affected by ALAN and display reduced activity (Downs 2003, Boldogh et al. 2007, Stone et al. 2009). ...
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• Bat populations are thought to have suffered significant declines in the past century throughout Europe. Fortunately, there are some signs of recovery; for instance, of the 11 species monitored in the UK, population trends of five are increasing. The drivers of past losses and recent trends are unclear; identifying them will enable targeted conservation strategies to support further recovery. • We review the evidence linking proposed drivers to impacts on bat populations in Europe, using the results of a previous cross‐taxa semi‐quantitative assessment as a framework. Broadly, the drivers reviewed relate to land‐use practices, climate change, pollution, development and infrastructure, and human disturbance. We highlight where evidence gaps or conflicts present barriers to successful conservation and review emerging opportunities to address these gaps. • We find that the relative importance or impacts of the potential drivers of bat population change are not well understood or quantified, with conflicting evidence in many cases. To close key gaps in the evidence for responses of bat populations to environmental change, future studies should focus on the impacts of climate change, urbanisation, offshore wind turbines, and water pollution, as well as on mitigation measures and the synergistic effects of putative drivers. • To increase available evidence of drivers of bat population change, we propose utilising advances in monitoring tools and statistical methods, together with robust quantitative assessment of conservation interventions to mitigate threats and enable the effective conservation of these protected species.
... Die Vertreter dieser Gattungen reagieren anscheinend auch gegenüber Kunstlicht neutral bzw. opportunistisch, indem sie z.B. die Insektenansammlungen an Straßenlaternen ausnutzen , LACOEUILHE et al. 2014, RYDELL 2006, RYDELL 1992, RYDELL 1991 ...
Thesis
Full-text available
The Western Barbastelle is one of the rarest, most endangered and most specialised bat species in Western Europe (COUZENS et al. 2017). Bavaria is the species’ stronghold within Germany which means that the state bears a special responsibility for the conservation of the species. While its occurrence all over the north, east and south-east of Bavaria has been verified there are larger gaps in the distribution in central and south-western Bavaria (LFU 2020b). Several nursery roosts of the species were known in the northern administrative district of Swabia (Günzburg) in the 1950s. Since then the Western Barbas-telle seemed to have withdrawn from this region for a long time (RUDOLPH 2004). In the last few years, probably also due to the improved technical possibilities in bat observation and numerous mappings in the context of wildlife conservation assessments (saP), an increasing number of acoustic recordings and nursery roost findings occurred (LFU 2020b). The present study also revealed numerous new locations of call records and nursery roosts of the spe-cies for the administrative district of Swabia, which suggests that the Western Barbastelle is again more widespread in the region. Examples from Italy (ANCILLOTTO et al. 2015), Portugal (REBELO & JONES 2010) and Latvia (PĒTERSONS, VINTULIS & ŠUBA 2010) show that targeted searches can lead to unexpected densi-fication and expansion of distribution maps. In order not to endanger the populations of the Western Barbastelle again, regional-specific data and knowledge are required so that the species can be adequately taken into account in forestry and agri-culture as well as in projects. Even if many secrets have been disclosed from the Western Barbastelle in recent years, its ecology and behaviour have by no means been conclusively researched. In addition, findings cannot be transferred to all occurrence areas without restrictions because the populations are adapted to different habitat conditions (ANCILLOTTO et al. 2014, REBELO & JONES 2010, SIERRO 1999, RU-DOLPH 2004). Accordingly, it is not surprising that the studies, individual observations and expert assess-ments available to date give a partly contradicting impression of the species and make it difficult to predict land use and project-related effects on the species. Expectations and observations regarding the influence of light on the habitat of the Western Barbas-telle go in different directions (VOIGT et al. 2019, RUSSO et al. 2017, LACOEUILHE et al. 2014, ANCILLOTTO et al. 2014, STONE 2013, ZINGG 1999), which is why the reaction of the species to light emissions in the Bavarian administrative district of Swabia was experimentally investigated with the present study. For a field test it was hypothesized that the species avoids artificial light and its acoustically detectable activi-ty is reduced under the influence of light. The experiment was carried out at ten locations in the districts of Neu-Ulm, Günzburg and Unterallgäu, with individuals of at least five different nursery communities being sampled. The intensely used hunting areas and flight routes were illuminated with two LED spotlights (4.500 lumens, 5.000 Kelvin, 50 W) in phases (15-minute intervals) while bat activity was measured in both the illuminated area and two non-illuminated control areas. During unlit phases, the activities were almost evenly distributed over the three recording locations, whereas the recording time was significantly reduced under the influence of the lighting. Lateral and vertical evasive manoeuvres as well as turning around in the illuminated area were the most frequently observed behavioural patterns, but apparently unimpaired through-flights were also occa-sionally recorded. For the also recorded species group Pipistrellus (mainly Pipistrelle bat) no significant effect of the lighting could be determined but was found for the genus Myotis. On average, 32.5% of the Barbastelle´s activities occurred during the illuminated phases. This proportion differed significantly from the genus Myotis (9.2%) but not compared to the genus Pipistrellus (44.6%), which suggests that the Western Barbastelle reacts light-shy, but apparently less strongly than the genus Myotis. The results of the present study provide a further contribution to the problem of “light emissions and bats” related to the German (Bavaria). They give clear indications that the Western Barbastelle is dis-turbed by new light sources on its flight routes and in its hunting habitats. The disturbance causes the species to fly detours and leave hunting habitats rich in food such as structured forest edges. Since there are no explicit data on the extent to which such disturbances lead to stress, energy loss, i.e. restrictions in fitness, it must be assumed that light emissions in preferred hunting habitats and traditio-nal flight routes negatively effect the conservation status of local populations thus the disruption ban according to BNatschG § 44 paragraph 2 is fulfilled. In addition, it has not been conclusively clarified which factors trigger collisions in the Barbastelle. The species is agile, fast and can orient over longer distances than the genera "Myotis" and "Plecotus", sometimes flies freely over highways, but also uses underpasses (SCHEWE 2015, KERTH & MELBER 2008). Nevertheless, it appears in the lists of road traffic victims (FENSOME & MATHEWS 2015). Irritations trigge-red by dynamic light (vehicle lights) could play a role, which temporarily disorientate the species in fast flight, lead to evasive action and, in the worst case, to collisions (ORBACH & FENTON 2010). Important sub-habitats of the species such as structurally rich forests and forest edges, riparian vege-taion, hedges and old trees in settled areas should also be taken into account for projects in the admi-nistrative district of Swabia at least within 7 kilometers of the nursery roosts. To minimize light-related impairments from street lamps, the methods described in VOIGT et al. (2019) are required. In addition, the effects of dynamic, vehicle-generated light in road planning should be estimated by modeling lighting scenarios and taken into account in route planning.
... Die Vertreter dieser Gattungen reagieren anscheinend auch gegenüber Kunstlicht neutral bzw. opportunistisch, indem sie z.B. die Insektenansammlungen an Straßenlaternen ausnutzen , LACOEUILHE et al. 2014, RYDELL 2006, RYDELL 1992, RYDELL 1991 ...
Thesis
The Western Barbastelle is one of the rarest, most endangered and most specialised bat species in Western Europe (COUZENS et al. 2017). Bavaria is the species’ stronghold within Germany which means that the state bears a special responsibility for the conservation of the species. While its occurrence all over the north, east and south-east of Bavaria has been verified there are larger gaps in the distribution in central and south-western Bavaria (LFU 2020b). Several nursery roosts of the species were known in the northern administrative district of Swabia (Günzburg) in the 1950s. Since then the Western Barbas-telle seemed to have withdrawn from this region for a long time (RUDOLPH 2004). In the last few years, probably also due to the improved technical possibilities in bat observation and numerous mappings in the context of wildlife conservation assessments (saP), an increasing number of acoustic recordings and nursery roost findings occurred (LFU 2020b). The present study also revealed numerous new locations of call records and nursery roosts of the spe-cies for the administrative district of Swabia, which suggests that the Western Barbastelle is again more widespread in the region. Examples from Italy (ANCILLOTTO et al. 2015), Portugal (REBELO & JONES 2010) and Latvia (PĒTERSONS, VINTULIS & ŠUBA 2010) show that targeted searches can lead to unexpected densi-fication and expansion of distribution maps. In order not to endanger the populations of the Western Barbastelle again, regional-specific data and knowledge are required so that the species can be adequately taken into account in forestry and agri-culture as well as in projects. Even if many secrets have been disclosed from the Western Barbastelle in recent years, its ecology and behaviour have by no means been conclusively researched. In addition, findings cannot be transferred to all occurrence areas without restrictions because the populations are adapted to different habitat conditions (ANCILLOTTO et al. 2014, REBELO & JONES 2010, SIERRO 1999, RU-DOLPH 2004). Accordingly, it is not surprising that the studies, individual observations and expert assess-ments available to date give a partly contradicting impression of the species and make it difficult to predict land use and project-related effects on the species. Expectations and observations regarding the influence of light on the habitat of the Western Barbas-telle go in different directions (VOIGT et al. 2019, RUSSO et al. 2017, LACOEUILHE et al. 2014, ANCILLOTTO et al. 2014, STONE 2013, ZINGG 1999), which is why the reaction of the species to light emissions in the Bavarian administrative district of Swabia was experimentally investigated with the present study. For a field test it was hypothesized that the species avoids artificial light and its acoustically detectable activi-ty is reduced under the influence of light. The experiment was carried out at ten locations in the districts of Neu-Ulm, Günzburg and Unterallgäu, with individuals of at least five different nursery communities being sampled. The intensely used hunting areas and flight routes were illuminated with two LED spotlights (4.500 lumens, 5.000 Kelvin, 50 W) in phases (15-minute intervals) while bat activity was measured in both the illuminated area and two non-illuminated control areas. During unlit phases, the activities were almost evenly distributed over the three recording locations, whereas the recording time was significantly reduced under the influence of the lighting. Lateral and vertical evasive manoeuvres as well as turning around in the illuminated area were the most frequently observed behavioural patterns, but apparently unimpaired through-flights were also occa-sionally recorded. For the also recorded species group Pipistrellus (mainly Pipistrelle bat) no significant effect of the lighting could be determined but was found for the genus Myotis. On average, 32.5% of the Barbastelle´s activities occurred during the illuminated phases. This proportion differed significantly from the genus Myotis (9.2%) but not compared to the genus Pipistrellus (44.6%), which suggests that the Western Barbastelle reacts light-shy, but apparently less strongly than the genus Myotis. The results of the present study provide a further contribution to the problem of “light emissions and bats” related to the German (Bavaria). They give clear indications that the Western Barbastelle is dis-turbed by new light sources on its flight routes and in its hunting habitats. The disturbance causes the species to fly detours and leave hunting habitats rich in food such as structured forest edges. Since there are no explicit data on the extent to which such disturbances lead to stress, energy loss, i.e. restrictions in fitness, it must be assumed that light emissions in preferred hunting habitats and traditio-nal flight routes negatively effect the conservation status of local populations thus the disruption ban according to BNatschG § 44 paragraph 2 is fulfilled. In addition, it has not been conclusively clarified which factors trigger collisions in the Barbastelle. The species is agile, fast and can orient over longer distances than the genera "Myotis" and "Plecotus", sometimes flies freely over highways, but also uses underpasses (SCHEWE 2015, KERTH & MELBER 2008). Nevertheless, it appears in the lists of road traffic victims (FENSOME & MATHEWS 2015). Irritations trigge-red by dynamic light (vehicle lights) could play a role, which temporarily disorientate the species in fast flight, lead to evasive action and, in the worst case, to collisions (ORBACH & FENTON 2010). Important sub-habitats of the species such as structurally rich forests and forest edges, riparian vege-taion, hedges and old trees in settled areas should also be taken into account for projects in the admi-nistrative district of Swabia at least within 7 kilometers of the nursery roosts. To minimize light-related impairments from street lamps, the methods described in VOIGT et al. (2019) are required. In addition, the effects of dynamic, vehicle-generated light in road planning should be estimated by modeling lighting scenarios and taken into account in route planning.
... Die Vertreter dieser Gattungen reagieren anscheinend auch gegenüber Kunstlicht neutral bzw. opportunistisch, indem sie z.B. die Insektenansammlungen an Straßenlaternen ausnutzen , LACOEUILHE et al. 2014, RYDELL 2006, RYDELL 1992, RYDELL 1991 ...
Thesis
The Western Barbastelle is one of the rarest, most endangered and most specialised bat species in Western Europe (COUZENS et al. 2017). Bavaria is the species’ stronghold within Germany which means that the state bears a special responsibility for the conservation of the species. While its occurrence all over the north, east and south-east of Bavaria has been verified there are larger gaps in the distribution in central and south-western Bavaria (LFU 2020b). Several nursery roosts of the species were known in the northern administrative district of Swabia (Günzburg) in the 1950s. Since then the Western Barbas-telle seemed to have withdrawn from this region for a long time (RUDOLPH 2004). In the last few years, probably also due to the improved technical possibilities in bat observation and numerous mappings in the context of wildlife conservation assessments (saP), an increasing number of acoustic recordings and nursery roost findings occurred (LFU 2020b). The present study also revealed numerous new locations of call records and nursery roosts of the spe-cies for the administrative district of Swabia, which suggests that the Western Barbastelle is again more widespread in the region. Examples from Italy (ANCILLOTTO et al. 2015), Portugal (REBELO & JONES 2010) and Latvia (PĒTERSONS, VINTULIS & ŠUBA 2010) show that targeted searches can lead to unexpected densi-fication and expansion of distribution maps. In order not to endanger the populations of the Western Barbastelle again, regional-specific data and knowledge are required so that the species can be adequately taken into account in forestry and agri-culture as well as in projects. Even if many secrets have been disclosed from the Western Barbastelle in recent years, its ecology and behaviour have by no means been conclusively researched. In addition, findings cannot be transferred to all occurrence areas without restrictions because the populations are adapted to different habitat conditions (ANCILLOTTO et al. 2014, REBELO & JONES 2010, SIERRO 1999, RU-DOLPH 2004). Accordingly, it is not surprising that the studies, individual observations and expert assess-ments available to date give a partly contradicting impression of the species and make it difficult to predict land use and project-related effects on the species. Expectations and observations regarding the influence of light on the habitat of the Western Barbas-telle go in different directions (VOIGT et al. 2019, RUSSO et al. 2017, LACOEUILHE et al. 2014, ANCILLOTTO et al. 2014, STONE 2013, ZINGG 1999), which is why the reaction of the species to light emissions in the Bavarian administrative district of Swabia was experimentally investigated with the present study. For a field test it was hypothesized that the species avoids artificial light and its acoustically detectable activi-ty is reduced under the influence of light. The experiment was carried out at ten locations in the districts of Neu-Ulm, Günzburg and Unterallgäu, with individuals of at least five different nursery communities being sampled. The intensely used hunting areas and flight routes were illuminated with two LED spotlights (4.500 lumens, 5.000 Kelvin, 50 W) in phases (15-minute intervals) while bat activity was measured in both the illuminated area and two non-illuminated control areas. During unlit phases, the activities were almost evenly distributed over the three recording locations, whereas the recording time was significantly reduced under the influence of the lighting. Lateral and vertical evasive manoeuvres as well as turning around in the illuminated area were the most frequently observed behavioural patterns, but apparently unimpaired through-flights were also occa-sionally recorded. For the also recorded species group Pipistrellus (mainly Pipistrelle bat) no significant effect of the lighting could be determined but was found for the genus Myotis. On average, 32.5% of the Barbastelle´s activities occurred during the illuminated phases. This proportion differed significantly from the genus Myotis (9.2%) but not compared to the genus Pipistrellus (44.6%), which suggests that the Western Barbastelle reacts light-shy, but apparently less strongly than the genus Myotis. The results of the present study provide a further contribution to the problem of “light emissions and bats” related to the German (Bavaria). They give clear indications that the Western Barbastelle is dis-turbed by new light sources on its flight routes and in its hunting habitats. The disturbance causes the species to fly detours and leave hunting habitats rich in food such as structured forest edges. Since there are no explicit data on the extent to which such disturbances lead to stress, energy loss, i.e. restrictions in fitness, it must be assumed that light emissions in preferred hunting habitats and traditio-nal flight routes negatively effect the conservation status of local populations thus the disruption ban according to BNatschG § 44 paragraph 2 is fulfilled. In addition, it has not been conclusively clarified which factors trigger collisions in the Barbastelle. The species is agile, fast and can orient over longer distances than the genera "Myotis" and "Plecotus", sometimes flies freely over highways, but also uses underpasses (SCHEWE 2015, KERTH & MELBER 2008). Nevertheless, it appears in the lists of road traffic victims (FENSOME & MATHEWS 2015). Irritations trigge-red by dynamic light (vehicle lights) could play a role, which temporarily disorientate the species in fast flight, lead to evasive action and, in the worst case, to collisions (ORBACH & FENTON 2010). Important sub-habitats of the species such as structurally rich forests and forest edges, riparian vege-taion, hedges and old trees in settled areas should also be taken into account for projects in the admi-nistrative district of Swabia at least within 7 kilometers of the nursery roosts. To minimize light-related impairments from street lamps, the methods described in VOIGT et al. (2019) are required. In addition, the effects of dynamic, vehicle-generated light in road planning should be estimated by modeling lighting scenarios and taken into account in route planning.
... Bat predation of adult moths is commonly observed around street lights (Frank, 1988;Rydell, 2006). Some species of bat exploit the high prey densities gathered around lamps (Rydell, 1992;Minnaar et al., 2015;Russo et al., 2019). ...
Article
Full-text available
1. The night-time environment is increasingly being lit, often by broad-spectrum lighting, and there is growing evidence that artificial light at night (ALAN) has consequences for ecosystems, potentially contributing to declines in insect populations. 2. Moths are species-rich, sensitive to ALAN, and have undergone declines in Europe, making them the ideal group for investigating the impacts of light pollution on nocturnal insects more broadly. Here, we take a life cycle approach to review the impacts of ALAN on moths, drawing on a range of disciplines including ecology, physiology, and applied entomology. 3. We find evidence of diverse impacts across most life stages and key behaviours. Many studies have examined flight-to-light behaviour in adults and our meta-analysis found that mercury vapour, metal halide, and compact fluorescent bulbs induce this more than LED and sodium lamps. However, we found that ALAN can also disrupt reproduction, larval development, and pupal diapause, with likely negative impacts on individual fitness, and that moths can be indirectly affected via hostplants and predators. These findings indicate that ALAN could also affect day-flying insects through impacts on earlier life stages. 4. Overall, we found strong evidence for effects of artificial light on moth behaviour and physiology, but little rigorous, direct evidence that this scales up to impacts on populations. Crucially, there is a need to determine the potential contribution of ALAN to insect declines, relative to other drivers of change. In the meantime, we recommend precautionary strategies to mitigate possible negative effects of ALAN on insect populations.
... ALAN leads to reduced commuting (Stone et al., 2009;Laforge et al., 2019), or drinking behaviour in bats, (Russo et al., 2017(Russo et al., , 2018, and can also contribute to roost abandonment (Boldogh et al., 2007;Rydell et al., 2017). The only documented benefit ALAN offers appears to be to provide increased foraging opportunity for some species (Rydell 1992(Rydell , 2013Blake et al., 1994). However, these results are not consistent across all bat species, and other studies have also demonstrated reduced foraging behaviour near ALAN (Stone et al., 2009;Russo et al., 2019). ...
Article
In an attempt to improve cost-effectiveness, it has become increasingly popular to adapt wildlife crossing structures to enable people to also use them for safe passage across roads. However, the required needs of humans and wildlife may conflict, resulting in a structure that does not actually provide the perceived improvement in cost-effectiveness, but instead a reduction in conservation benefits. For example, lighting within crossing structures for human safety at night may reduce use of the structure by nocturnal wildlife, thus contributing to barrier and mortality effects of roads rather than mitigating them. In this study, we experimentally evaluated the impact of artificial light at night on the rate of use of wildlife crossing structures, specifically underpasses, by ten insectivorous bat species groups in south-eastern Australia. We monitored bat activity before, during and after artificially lighting the underpasses. We found that bats tended to avoided lit underpasses, and only one species consistently showed attraction to the light. Artificial light at night in underpasses hypothetically increases the vulnerability of bats to road-mortality or to the barrier effect of roads. The most likely outcomes of lighting underpasses were 1. an increase in crossing rate above the freeway and a decrease under the underpasses, or 2. a reduction in crossing rate both above freeways and under the underpasses, when structures were lit. Our results corroborate those of studies on terrestrial mammals, and thus we recommend that underpasses intended to facilitate the movement of wildlife across roads should not be lit.
... The high activity of L. varius observed in local human settlements could be explained by its ability to fly in open spaces and its reliance on insects that accumulate around streetlights (Jung and Kalko 2010;Rodríguez-San Pedro and Simonetti 2013b). Medium-size fast-flying bats, such as those of the genus Lasiurus, typically fly back and forth in straight flight along rows of streetlights, patrol the street and dive toward insects in the light cone; this behavior is the most characteristic of bats that hunt near lights (Rydell 2006). L. varius is a fast-flying species with low maneuverability, expected to be clutter-sensitive (Schnitzler et al. 2003;Simonetti 2014, 2015). ...
Article
Full-text available
Lasiurus varius (Poeppig, 1835) is a vespertilionid bat commonly known as Chilean red bat or cinnamon red bat. L. varius is characterized by its deep reddish coloration without frosted appearance, and by the uropatagium covered with long hairs that extend beyond the trailing edge, which clearly distinguishes it from the other species in the genus. The distribution of this rare species is restricted to the southern parts of Argentina and Chile.
... Furthermore, when lit, roads also attract insects and therefore favour those species not disturbed by lights, such as Pipistrellus, Nyctalus and Eptesicus spp. (Rowse, Lewanzik, Stone, Harris, & Jones, 2016;Rydell, 2006;Spoelstra et al., 2017). ...
Article
Full-text available
Aim Bats are important components of mammalian biodiversity and strong bioindicators, but their fine‐scale distributions often remain less known than other taxa (e.g., plants, birds). Yet as highly mobile species with multiple needs in the landscape, bats impose serious modelling challenges, such as advanced use of neighbourhood analyses. The aims of this study were to test the use of a designed sampling of bats for biodiversity and conservation assessments, and to find appropriate modelling solutions for providing nature practitioners with reliable potential bat distribution maps in a mountain area of high conservation interest. Location The western Swiss Alps of Vaud. Methods We conducted a one‐year field survey combining passive acoustic recordings supplemented by mist net catching to collect data on bats. These data were then used to create univariate models with focal land use/cover variables using different focal window sizes to detect the optimal species‐specific scale of influence for each variable. The large number of selected variables was then used to create ensembles of small models at a 100 m × 100 m resolution, and the resulting habitat suitability maps were transformed into species distribution maps for practitioners. Results We were able to collect data to model 14 different bat species representing 66% of the Swiss bat diversity, including four red list species. In general, the most important variables were Euclidean distance to road or water, temperature and slope, but there was large variation among species both for the variable importance and for the optimal focal window size. Main conclusion Our study greatly increased the knowledge of bats in this region and showed that many of the red list species are nowadays disappearing from the intensively used lowland plains and restricted to the remaining forests along the slopes. Additionally, we highlighted the importance of selecting the variable scale on a species‐specific basis accounting for their mobility and range sizes.
... Insects that are attracted to ALAN sources are readily exploited by predators: Orb-weaving spiders prefer artificially lit web sites (Enders, 1977), which may net them more prey (Heiling, 1999, but see Yuen & Bonebrake, 2017). Bats (Jung & Kalko, 2010;Minnaar et al., 2015;Rydell, 2006), birds (Robertson, Kriska, Horvath, & Horvath, 2010), and invasive cane toads (González-Bernal, Greenlees, Brown, & Shine, 2016) congregate around streetlights and lit buildings for a similar reason. Usually, diurnal anole lizards and jumping spiders have been observed hunting for insects at night in artificially illuminated locations (Frank, 2009;Garber, 1978;Wolff, 1982). ...
Article
Full-text available
In recent decades, advances in lighting technology have precipitated exponential increases in night sky brightness worldwide, raising concerns in the scientific community about the impact of artificial light at night (ALAN) on crepuscular and nocturnal biodiversity. Long‐term records show that insect abundance has declined significantly over this time, with worrying implications for terrestrial ecosystems. The majority of investigations into the vulnerability of nocturnal insects to artificial light have focused on the flight‐to‐light behavior exhibited by select insect families. However, ALAN can affect insects in other ways as well. This review proposes five categories of ALAN impact on nocturnal insects, highlighting past research and identifying key knowledge gaps. We conclude with a summary of relevant literature on bioluminescent fireflies, which emphasizes the unique vulnerability of terrestrial light‐based communication systems to artificial illumination. Comprehensive understanding of the ecological impacts of ALAN on diverse nocturnal insect taxa will enable researchers to seek out methods whereby fireflies, moths, and other essential members of the nocturnal ecosystem can coexist with humans on an increasingly urbanized planet.
... Consequently, ALAN elicits avoidance behaviour in most bat species, apart from a few opportunistic species that exploit insects congregating near streetlamps (e.g. Rydell, 2006;Schoeman, 2016), because it makes the bat more visible, thus increasing (real or per- ceived) predation risk. Of the few light-exploiting bat spe- cies, some may cross or commute at illuminated sites because they fly fast, and escape predators more efficiently, which makes them less at risk under such conditions (Mathews et al., 2015). ...
Article
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.
... Light pollution has the potential to intensify (Rydell 2006;Miller et al. 2017) or weaken (McMahon et al. 2017) intra-and inter-specific interactions through its effects on movement and behavior. Though our results suggest the predator-prey interaction between the two species we studied is weak (the predator species never consumed the prey species in our mesocosm experiment), light pollution may further weaken this interaction because light pollution strongly inhibited flashing behaviors (Fig. 4B), which the predator species use to lure the prey species. ...
Article
Light pollution impacts both intra- and inter-specific interactions, such as interactions between mates and predator–prey interactions. In mobile organisms attracted to artificial lights, the effect of light pollution on these interactions may be intensified. If organisms are repelled by artificial lights, effects of light pollution on intra- and inter-specific interactions may be diminished as organisms move away. However, organisms repelled by artificial lights would likely lose suitable habitat as light pollution expands. Thus, we investigated how light pollution affects both net attraction or repulsion of organisms and effects on intra- and inter-specific interactions. In manipulative field studies using fireflies, we found that Photuris versicolor and Photinus pyralis fireflies were lured to artificial (LED) light at night and that both species were less likely to engage in courtship dialogues (bioluminescent flashing) in light-polluted field plots. Light pollution also lowered the mating success of P. pyralis. P. versicolor is known to prey upon P. pyralis by mimicking the flash patterns of P. pyralis, but we did not find an effect of light pollution on Photuris–Photinus predator–prey interactions. Our study suggests, that for some nocturnal insects, light-polluted areas may act as demographic traps, i.e., areas where immigration exceeds emigration and inhibition of courtship dialogues and mating reduces reproduction. Examining multiple factors affecting population growth in concert is needed to understand and mitigate impacts of light pollution on wildlife.
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The Mexican free-tailed bat (Tadarida brasiliensis) is an abundant, widely distributed species in Mexico, except for most of the Yucatán peninsula. We studied the helminth fauna of T. b. mexicana at seven localities in the State of Zacatecas in order to advance the knowledge of helminth parasites of wild vertebrates in northern-central Mexico. Eighty-four bat specimens were examined for the presence of helminth parasites following standard procedures; helminths found were identified and infections were characterized. Of the specimens examined, 65.47 % were parasitized. The helminth fauna comprises five taxa: three digeneans (Dicrocoelium rileyi, Ochoterenatrema labda, and Urotrema scabridum); one cestode (Vampirolepis sp.); and one nematode (Tadaridanema delicatus). We present a brief morphological description of Urotrema scabridum. D. rileyi was the most prevalent and abundant helminth species. The intestine was the habitat most parasitized, with four species. Indirect life cycles predominate, and are related to the insectivorous habits of this host. Further studies on this host-parasite system are necessary to contribute to population monitoring and conservation; biogeographic patterns of helminth parasites of bats should also be studied to explore their origins and evolution in the region. U. scabridum is reported for the first time from Zacatecas. All species are new locality records.
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Alternation of day and night is the oldest cycle on Earth, which is increasingly disturbed by the accelerating rate of urbanization and technological development. Despite the ubiquity of light pollution in cities, many aspects of its influence on urban ecosystems are still poorly understood. Here we studied the effect of artificial light at night (ALAN) on the biomass of arboreal caterpillar populations, which are a major component of the diet of many insectivorous animals. We predicted that increasing ALAN intensity is associated with reduced caterpillar biomass, because ALAN may increase predation risk for both caterpillars and adult lepidopterans (i.e. moths), and can also hinder the moths’ reproductive rate. We estimated caterpillar biomass from frass samples (n = 3061) collected from 36 focal trees in two cities in Hungary during four consecutive years. To quantify ALAN we measured light intensity during night at each focal tree (range of illumination: 0.69–3.18 lx). We found that caterpillar biomass of individual trees was repeatable over the four years. This temporal consistency in prey biomass production may be important for birds because it can help predict territory quality, especially in cities where caterpillar abundance is generally low. Our results did not support the negative effect of ALAN on urban caterpillar populations, because ALAN intensity was not related to caterpillar biomass, and this lack of effect was consistent between study sites and tree species. We suggest that the effect of ALAN on urban caterpillar biomass is either weak and thus can be masked by other, local environmental factors, or light pollution may have antagonistic effects acting during different stages of the lepidopteran life cycle. Another explanation could be that even the lower levels of our sites’ public lighting are strong enough to cause serious detrimental effects for caterpillars, resulting in their uniformly low biomass.
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Artificial light at night is considered a major threat to biodiversity, especially for nocturnal species, as it reduces habitat availability, quality, and functionality. Since the recent evolution in light technologies in improving luminous efficacy, developed countries are experiencing a renewal of their lighting equipment that reaches its end-of-life, from conventional lighting technologies to light emitting diodes (LEDs). Despite potential cascading impacts of such a shift on nocturnal fauna, few studies have so far dealt with the impact of the renewal of street lighting by new technologies. Specifically, only one study, by Rowse et al.2016, examined the effects of switching from widely used low pressure sodium (LPS) lamps to LEDs, using bats as biological models. This study was based on a before-after-control-impact paired design (BACIP) at 12 pairs in the UK, each including one control and one experimental streetlight. If Rowse et al. 2016 showed no effect of switching to LEDs streetlights on bat activity, the effects of respective changes in light intensity and spectrum were not disentangled when testing switch effects. Here, we conduct a retrospective analysis of their data to include these covariates in statistical models with the aim of disentangling the relative effects of these light characteristics. Our re-analysis clearly indicates that the switches in spectrum and in intensity with replacement of LPS with LED lamps have significant additive and interactive effects, on bat activity. We also show that bat activity and buzz ratio decrease with increasing LED intensity while an opposite effect is observed with LPS lamps. Hence, the loss or the gain in bat activity when lamp types, i.e., spectrum, are switched strongly depends on the initial and new lamp intensities. Our results stress the need to consider simultaneously the effects of changes in the different lights characteristics when street lighting changes. Because switches from LPS to LED lamps can lead to an increase in light intensity, such technological changes may involve a reduction of bat activity in numerous cases, especially at high LED intensities. Since we are currently at an important crossroad in lighting management, we recommend to limit LED intensity and improve its spectral composition toward warmer colors to limit potential deleterious impacts on bat activity.
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The widespread use of electric lamps has created "ecological light pollution" and "artificial light ecology." Given the important role of insects in ecosystems, how they are affected by light pollution deserves attention. Lamps designed for lighting small areas around residences are used in abundance, but studies specifically examining them are scarce. This study used a light trap to capture insects for 60 summer nights in a suburban town in Virginia, USA. During each night of trapping, one of five different light bulbs was used in the trap (incandescent, compact fluorescent, halogen, warm color temperature LED, or cool color temperature LED). The data suggest that fewer insects overall are attracted to bulbs using LED technology than bulbs using incandescent technology. This difference was also observed in the orders Lepidoptera and Diptera. These results support the use of LED bulbs to reduce the insect attraction and mortality caused by the use of artificial lights at night.
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The vehicular flow impacts the vertebrate community through the collision of specimens, but the effect that the light intensity and noise of vehicles generates on the structure of the bat community in tropical forests is still unknown. The objectives of the study were i) to describe the structure of the bat community and ii) to relate the monthly wealth and abundance of the bat community with respect to vehicular flow in a fragment of medium sub-evergreen forest in the central zone of Veracruz, Mexico. At km 11 of the Córdoba-Veracruz highway, monthly monitoring was carried out for three nights for six months, bats were captured with fog nets and classified by species and trophic guild. The community structure was described with the effective number of species and compared between monitoring sites. With a regression test, monthly bat abundance and richness were related to vehicular flow to test the association between these variables. With 19,170 h / net, 127 individuals from two families, nine genera and 12 species were captured. The effective numbers of species were not significantly different between sites and the regression analysis showed no effect of vehicular flow on the richness and monthly abundance of bats. Noise and light intensity caused by vehicles has a minimal impact on bat populations, as there are no changes in the structure of the community.
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