|   | 
Details
   web
Records
Author Eriksen, A.; Wabakken, P.
Title Activity patterns at the Arctic Circle: nocturnal eagle owls and interspecific interactions during continuous midsummer daylight Type Journal Article
Year 2018 Publication (down) Journal of Avian Biology Abbreviated Journal J Avian Biol
Volume 49 Issue 7 Pages e01781
Keywords Animals
Abstract Circadian rhythms result from adaptations to biotic and abiotic environmental conditions that cycle through the day, such as light, temperature, or temporal overlap between interacting species. At high latitudes, close to or beyond the polar circles, uninterrupted midsummer daylight may pose a challenge to the circadian rhythms of otherwise nocturnal species, such as eagle owls Bubo bubo. By non‐invasive field methods, we studied eagle owl activity in light of their interactions with their main prey the water vole Arvicola amphibius, and their competitor the white‐tailed eagle Haliaeetus albicilla during continuous midsummer daylight on open, treeless islands in coastal Northern Norway. We evaluated circadian rhythms, temporal overlap, exposure, and spatial distribution. The owls maintained a nocturnal activity pattern, possibly because slightly dimmer light around midnight offered favourable hunting conditions. The eagles were active throughout the 24‐hour period as opposed to the strictly diurnal rhythm reported elsewhere, thus increasing temporal overlap and the potential for interference competition between the two avian predators. This may indicate an asymmetry, with the owls facing the highest cost of interference competition. The presence of eagles combined with constant daylight in this open landscape may make the owls vulnerable to interspecific aggression, and contrary to the available literature, eagle owls rarely exposed themselves visually during territorial calls, possibly to avoid detection by eagles. We found indications of spatial segregation between owls and eagles reflecting differences in main prey, possibly in combination with habitat‐mediated avoidance. Eagle owl vocal activity peaked in the evening before a nocturnal peak in visual observations, when owls were active hunting, consistent with the hypothesis of a dusk chorus in nocturnal bird species. The owls may have had to trade‐off between calling and foraging during the few hours around midnight when slightly dimmer light reduced the detection risk while also providing better hunting conditions.
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 0908-8857 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1881
Permanent link to this record
 

 
Author Holveck, M.-J.; Grégoire, A.; Doutrelant, C.; Lambrechts, M.M.
Title Nest height is affected by lamppost lighting proximity in addition to nestbox size in urban great tits Type Journal Article
Year 2018 Publication (down) Journal of Avian Biology Abbreviated Journal J Avian Biol
Volume in press Issue Pages
Keywords Animals
Abstract Both natural and artificial light have proximate influences on many aspects of avian biology, physiology and behaviour. To date artificial light at night is mostly considered as being a nuisance disrupting for instance sleep and reproduction of diurnal species. Here, we investigate if lamppost night lighting affects cavity‐nesting bird species inside their breeding cavity. Nest height in secondary cavity‐nesting species is the result of trade‐offs between several selective forces. Predation is the prevailing force leading birds to build thin nests to increase the distance towards the entrance hole. A thin nest may also limit artificial light exposure at night. Yet, a minimum level of daylight inside nesting cavities is necessary for adequate visual communication and/or offspring development. Against this background, we hypothesised that avian nest‐building behaviour varies in response to a change in night lighting. We monitored nest height of urban great tits (Parus major) during six years and found that it varied with artificial light proximity. The birds built thinner nests inside nestboxes of various sizes in response to increasing lamppost night light availability at the nest. In large nestboxes, the nests were also thinner when a lamppost was present in the territory. Whether this relationship between artificial night lighting and nest height reflects a positive or negative effect of urbanisation is discussed in the light of recent experimental studies conducted in rural populations by other research groups.
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 0908-8857 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2062
Permanent link to this record
 

 
Author Zachary M. Cravens, Veronica A. Brown, Timothy J. Divoll, Justin G. Boyles
Title Illuminating prey selection in an insectivorous bat community, exposed to artificial light at night Type Journal Article
Year 2018 Publication (down) Journal of Applied Ecology Abbreviated Journal
Volume 55 Issue 2 Pages 705-713
Keywords Animals; Ecology
Abstract 1.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.
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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1783
Permanent link to this record
 

 
Author Gaston, K.J.; Holt, L.A.
Title Nature, extent and ecological implications of night‐time light from road vehicles Type Journal Article
Year 2018 Publication (down) Journal of Applied Ecology Abbreviated Journal
Volume 55 Issue 5 Pages 2296-2307
Keywords Animals; Ecology; Lighting; Review
Abstract The erosion of night‐time by the introduction of artificial lighting constitutes a profound pressure on the natural environment. It has altered what had for millennia been reliable signals from natural light cycles used for regulating a host of biological processes, with impacts ranging from changes in gene expression to ecosystem processes.

Studies of these impacts have focused almost exclusively on those resulting from stationary sources of light emissions, and particularly streetlights. However, mobile sources, especially road vehicle headlights, contribute substantial additional emissions.

The ecological impacts of light emissions from vehicle headlights are likely to be especially high because these are (1) focused so as to light roadsides at higher intensities than commonly experienced from other sources, and well above activation thresholds for many biological processes; (2) projected largely in a horizontal plane and thus can carry over long distances; (3) introduced into much larger areas of the landscape than experience street lighting; (4) typically broad “white” spectrum, which substantially overlaps the action spectra of many biological processes and (5) often experienced at roadsides as series of pulses of light (produced by passage of vehicles), a dynamic known to have major biological impacts.

The ecological impacts of road vehicle headlights will markedly increase with projected global growth in numbers of vehicles and the road network, increasing the local severity of emissions (because vehicle numbers are increasing faster than growth in the road network) and introducing emissions into areas from which they were previously absent. The effects will be further exacerbated by technological developments that are increasing the intensity of headlight emissions and the amounts of blue light in emission spectra.

Synthesis and applications. Emissions from vehicle headlights need to be considered as a major, and growing, source of ecological impacts of artificial night‐time lighting. It will be a significant challenge to minimise these impacts whilst balancing drivers' needs at night and avoiding risk and discomfort for other road users. Nonetheless, there is potential to identify solutions to these conflicts, both through the design of headlights and that of roads.
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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1841
Permanent link to this record
 

 
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 (down) 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 0021-8901 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number NC @ ehyde3 @ Serial 2086
Permanent link to this record