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Author Minnaar, C.; Boyles, J.G.; Minnaar, I.A.; Sole, C.L.; McKechnie, A.E.; McKenzie, A.
Title Stacking the odds: light pollution may shift the balance in an ancient predator-prey arms race Type Journal Article
Year 2014 Publication Journal of Applied Ecology Abbreviated Journal J Appl Ecol
Volume 52 Issue 2 Pages 522-531
Keywords Ecology; animals; bats; insects; predation; Neoromicia capensis; moths; Cape serotine bat; co-evolution; eared moth; Lepidoptera; predator–prey interactions; prey selection
Abstract 1. Artificial night lighting threatens to disrupt strongly conserved light-dependent processes in animals and may have cascading effects on ecosystems as species interactions become altered. Insectivorous bats and their prey have been involved in a nocturnal, co-evolutionary arms race for millions of years. Lights may interfere with anti-bat defensive behaviours in moths, and disrupt a complex and globally ubiquitous interaction between bats and insects, ultimately leading to detrimental consequences for ecosystems on a global scale.

2. We combined experimental and mathematical approaches to determine effects of light pollution on a free-living bat–insect community. We compared prey selection by Cape serotine bats Neoromicia capensis in naturally unlit and artificially lit conditions using a manipulative field experiment, and developed a probabilistic model based on a suite of prey-selection factors to explain differences in observed diet.

3.Moth consumption by N. capensis was low under unlit conditions (mean percentage volume ± SD: 5·91 ± 6·25%), while moth consumption increased sixfold (mean percentage volume ± SD: 35·42 ± 17·90%) under lit conditions despite a decrease in relative moth abundance. Predictive prey-selection models that included high-efficacy estimates for eared-moth defensive behaviour found most support given diet data for bats in unlit conditions. Conversely, models that estimated eared-moth defensive behaviour as absent or low found more support given diet data for bats in lit conditions. Our models therefore suggest the increase in moth consumption was a result of light-induced, decreased eared-moth defensive behaviour.

4. Policy implications. In the current context of unyielding growth in global light pollution, we predict that specialist moth-eating bats and eared moths will face ever-increasing challenges to survival through increased resource competition and predation risk, respectively. Lights should be developed to be less attractive to moths, with the goal of reducing effects on moth behaviour. Unfortunately, market preference for broad-spectrum lighting and possible effects on other taxa make development of moth-friendly lighting improbable. Mitigation should therefore focus on the reduction of temporal, spatial and luminance redundancy in outdoor lighting. Restriction of light inside nature reserves and urban greenbelts can help maintain dark refugia for moth-eating bats and moths, and may become important for their persistence.
Address Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Hatfield, South Africa
Corporate Author Thesis
Publisher Wiley Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 0021-8901 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ christopher.kyba @; IDA @ john @ Serial 1085
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Author Lewanzik, D.; Voigt, C.C.; Minderman, J.
Title Transition from conventional to light-emitting diode street lighting changes activity of urban bats Type Journal Article
Year 2016 Publication Journal of Applied Ecology Abbreviated Journal J Appl Ecol
Volume 54 Issue 1 Pages 264-271
Keywords Animals; Bats
Abstract Light pollution is rapidly increasing and can have deleterious effects on biodiversity, yet light types differ in their effect on wildlife. Among the light types used for street lamps, light-emitting diodes (LEDs) are expected to become globally predominant within the next few years.

In a large-scale field experiment, we recorded bat activity at 46 street lights for 12 nights each and investigated how the widespread replacement of conventional illuminants by LEDs affects urban bats: we compared bat activity at municipal mercury vapour (MV) street lamps that were replaced by LEDs with control sites that were not changed.

Pipistrellus pipistrellus was the most frequently recorded species; it was 45% less active at LEDs than at MV street lamps, but the activity did not depend on illuminance level. Light type did not affect the activity of Pipistrellus nathusii, Pipistrellus pygmaeus or bats in the Nyctalus/Eptesicus/Vespertilio (NEV) group, yet the activity of P. nathusii increased with illuminance level. Bats of the genus Myotis increased activity 4·5-fold at LEDs compared with MV lights, but illuminance level had no effect.

Decreased activity of P. pipistrellus, which are considered light tolerant, probably paralleled insect densities around lights. Further, our results suggest that LEDs may be less repelling for light-averse Myotis spp. than MV lights. Accordingly, the transition from conventional lighting techniques to LEDs may greatly alter the anthropogenic impact of artificial light on urban bats and might eventually affect the resilience of urban bat populations.

Synthesis and applications. At light-emitting diodes (LEDs), the competitive advantage – the exclusive ability to forage on insect aggregations at lights – is reduced for light-tolerant bats. Thus, the global spread of LED street lamps might lead to a more natural level of competition between light-tolerant and light-averse bats. This effect could be reinforced if the potential advantages of LEDs over conventional illuminants are applied in practice: choice of spectra with relatively little energy in the short wavelength range; reduced spillover by precisely directing light; dimming during low human activity times; and control by motion sensors. Yet, the potential benefits of LEDs could be negated if low costs foster an overall increase in artificial lighting.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 0021-8901 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1518
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Author Bennie, J.; Davies, T.W.; Cruse, D.; Inger, R.; Gaston, K.J.; Lewis, O.
Title Artificial light at night causes top-down and bottom-up trophic effects on invertebrate populations Type Journal Article
Year 2018 Publication Journal of Applied Ecology Abbreviated Journal J Appl Ecol
Volume 55 Issue 6 Pages 2698-2706
Keywords Ecology; Animals; Plants
Abstract Globally, many ecosystems are exposed to artificial light at night. Nighttime lighting has direct biological impacts on species at all trophic levels. However, the effects of artificial light on biotic interactions remain, for the most part, to be determined.

We exposed experimental mesocosms containing combinations of grassland plants and invertebrate herbivores and predators to illumination at night over a 3‐year period to simulate conditions under different common forms of street lighting.

We demonstrate both top‐down (predation‐controlled) and bottom‐up (resource‐controlled) impacts of artificial light at night in grassland communities. The impacts on invertebrate herbivore abundance were wavelength‐dependent and mediated via other trophic levels.

White LED lighting decreased the abundance of a generalist herbivore mollusc by 55% in the presence of a visual predator, but not in its absence, while monochromatic amber light (with a peak wavelength similar to low‐pressure sodium lighting) decreased abundance of a specialist herbivore aphid (by 17%) by reducing the cover and flower abundance of its main food plant in the system. Artificial white light also significantly increased the food plant's foliar carbon to nitrogen ratio.

We conclude that exposure to artificial light at night can trigger ecological effects spanning trophic levels, and that the nature of such impacts depends on the wavelengths emitted by the lighting technology employed.

Policy implications. Our results confirm that artificial light at night, at illuminance levels similar to roadside vegetation, can have population effects mediated by both top‐down and bottom‐up effects on ecosystems. Given the increasing ubiquity of light pollution at night, these impacts may be widespread in the environment. These results underline the importance of minimizing ecosystem disruption by reducing light pollution in natural and seminatural ecosystems.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 0021-8901 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number NC @ ehyde3 @ Serial 2086
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Author Wakefield, A.; Broyles, M.; Stone, E.L.; Harris, S.; Jones, G.; Minderman, J.
Title Quantifying the attractiveness of broad-spectrum street lights to aerial nocturnal insects Type Journal Article
Year 2018 Publication Journal of Applied Ecology Abbreviated Journal J Appl Ecol
Volume 55 Issue 2 Pages 714-722
Keywords Animals
Abstract 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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 0021-8901 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2224
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Author Bennie, J.; Davies, T.W.; Cruse, D.; Gaston, K.J.
Title Ecological effects of artificial light at night on wild plants Type Journal Article
Year 2016 Publication Journal of Ecology Abbreviated Journal J Ecol
Volume 104 Issue 3 Pages 611-620
Keywords Plants; wild plants; photobiology; Circadian; Ecophysiology; light cycles; light pollution; photoperiodism; photopollution; physiology; sky glow; urban ecology
Abstract 1.Plants use light as a source of both energy and information. Plant physiological responses to light, and interactions between plants and animals (such as herbivory and pollination), have evolved under a more or less stable regime of 24-hour cycles of light and darkness, and, outside of the tropics, seasonal variation in daylength.

2.The rapid spread of outdoor electric lighting across the globe over the past century has caused an unprecedented disruption to these natural light cycles. Artificial light is widespread in the environment, varying in intensity by several orders of magnitude from faint skyglow reflected from distant cities to direct illumination of urban and suburban vegetation.

3.In many cases artificial light in the nighttime environment is sufficiently bright to induce a physiological response in plants, affecting their phenology, growth form and resource allocation. The physiology, behaviour and ecology of herbivores and pollinators is also likely to be impacted by artificial light. Thus, understanding the ecological consequences of artificial light at night is critical to determine the full impact of human activity on ecosystems.

4.Synthesis. Understanding the impacts of artificial nighttime light on wild plants and natural vegetation requires linking the knowledge gained from over a century of experimental research on the impacts of light on plants in the laboratory and greenhouse with knowledge of the intensity, spatial distribution, spectral composition and timing of light in the nighttime environment. To understand fully the extent of these impacts requires conceptual models that can (i) characterise the highly heterogeneous nature of the nighttime light environment at a scale relevant to plant physiology, and (ii) scale physiological responses to predict impacts at the level of the whole plant, population, community and ecosystem.
Address Environment and Sustainability Institute, University of Exeter, Penryn, United Kimgdom; j.j.bennie(at)exeter.ac.uk
Corporate Author Thesis
Publisher Wiley Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 0022-0477 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1350
Permanent link to this record