scholarly journals Blue light attracts nocturnally migrating birds

The Condor ◽  
2020 ◽  
Vol 122 (2) ◽  
Author(s):  
Xuebing Zhao ◽  
Min Zhang ◽  
Xianli Che ◽  
Fasheng Zou

Abstract Light pollution is increasing and artificial light sources have great impacts on animals. For migrating birds, collisions caused by artificial light pollution are a significant source of mortality. Laboratory studies have demonstrated that birds have different visual sensitivities to different colors of light, but few field experiments have compared birds’ responses to light of different wavelengths. We used 3 monochromatic lights (red, green, and blue) and polychromatic yellow light to study the impact of wavelength on phototaxis at 2 gathering sites of nocturnally migrating birds in Southwest China. For both sites, short-wavelength blue light caused the strongest phototactic response. In contrast, birds were rarely attracted to long-wavelength red light. The attractive effect of blue light was greatest during nights with fog and headwinds. As rapid urbanization and industrialization cause an increase in artificial light, we suggest that switching to longer wavelength lights is a convenient and economically effective way to reduce bird collisions.

2021 ◽  
Author(s):  
Christina Diamantopoulou ◽  
Eleni Christoforou ◽  
Davide M. Dominoni ◽  
Eirini Kaiserli ◽  
Jakub Czyzewski ◽  
...  

AbstractArtificial light at night (ALAN) is increasingly recognised as a disruptive form of environmental pollution, impacting many physiological and behavioural processes that may scale up to population and community-level effects. Mounting evidence from animal studies show that the severity and type of the impact depends on the wavelength and intensity of ALAN. This knowledge has been instrumental for informing policy-making and planning for wildlife-friendly illumination. However, most of this evidence comes from terrestrial habitats, while research testing alternative wavelength illumination in marine environments is lagging behind. In this study we investigated the effect of such alternative ALAN colours on marine primary producers. Specifically, we tested the effect of green, red, and natural white LED illumination at night, compared to a dark control, on the growth of a green microalgae as well as the biomass, diversity and composition of a phytoplankton assemblage. Our findings show that green ALAN boosted chlorophyll production at the exponential growth stage, resulting in higher biomass production in the green algae Tetraselmis suesica. All ALAN wavelengths affected the biomass and diversity of the assemblage with the red and green ALAN having the stronger effects, leading to higher overall abundance and selective dominance of specific diatom species compared to white ALAN and the dark control.SynthesisOur work indicates that the wavelength of artificial light sources in marine areas should be carefully considered in management and conservation plans. In particular, green and red light should be used with caution in coastal areas, where there might be a need to strike a balance between the strong effects of green and red light on marine primary producers with the benefit they bring to other organisms.


2021 ◽  
Vol 9 ◽  
Author(s):  
Wouter Halfwerk ◽  
Paul Jerem

Levels of anthropogenic noise and artificial light at night (ALAN) are rapidly rising on a global scale. Both sensory pollutants are well known to affect animal behavior and physiology, which can lead to substantial ecological impacts. Most studies on noise or light pollution to date have focused on single stressor impacts, studying both pollutants in isolation despite their high spatial and temporal co-occurrence. However, few studies have addressed their combined impact, known as multisensory pollution, with the specific aim to assess whether the interaction between noise and light pollution leads to predictable, additive effects, or less predictable, synergistic or antagonistic effects. We carried out a systematic review of research investigating multisensory pollution and found 28 studies that simultaneously assessed the impact of anthropogenic noise and ALAN on animal function (e.g., behavior, morphology or life-history), physiology (e.g., stress, oxidative, or immune status), or population demography (e.g., abundance or species richness). Only fifteen of these studies specifically tested for possible interactive effects when both sensory pollutants were combined. Four out of eight experimental studies revealed a significant interaction effect, in contrast to only three out seven observational studies. We discuss the benefits and limitations of experimental vs. observational studies addressing multisensory pollution and call for more specific testing of the diverse ways in which noise and light pollution can interact to affect wildlife.


2019 ◽  
Vol 491 (4) ◽  
pp. 5586-5594
Author(s):  
Miroslav Kocifaj ◽  
František Kundracik ◽  
Ondrej Bilý

ABSTRACT The emission spectrum of a light-pollution source is a determining factor for modelling artificial light at night. The spectral composition of skyglow is normally derived from the initial spectra of all artificial light sources contributing to the diffuse illumination of an observation point. However, light scattering in the ambient atmosphere imposes a wavelength-specific distortion on the optical signals captured by the measuring device. The nature of the emission, the spectra and the light-scattering phenomena not only control the spectral properties of the ground-reaching radiation, but also provide a unique tool for remote diagnosis and even identification of the emission spectra of the light-polluting sources. This is because the information contained in the night-sky brightness is preferably measured in directions towards a glowing dome of light over the artificial source of light. We have developed a new method for obtaining the emission spectra using remote terrestrial sensing of the bright patches of sky associated with a source. Field experiments conducted in Vienna and Bratislava have been used to validate the theoretical model and the retrieval method. These experiments demonstrate that the numerical inversion is successful even if the signal-to-noise ratio is small. The method for decoding the emission spectra by the light-scattering spectrometry of a night sky is a unique approach that enables for (i) a systematic characterization of the light-pollution sources over a specific territory, and (ii) a significant improvement in the numerical prediction of skyglow changes that we can expect at observatories.


2020 ◽  
Vol 12 (20) ◽  
pp. 3412
Author(s):  
Andreas Jechow ◽  
Franz Hölker

Artificial skyglow, the brightening of the night sky by artificial light at night that is scattered back to Earth within the atmosphere, is detrimental to astronomical observations and has an impact on ecosystems as a form of light pollution. In this work, we investigated the impact of the lockdown caused by the COVID-19 pandemic on the urban skyglow of Berlin, Germany. We compared night sky brightness and correlated color temperature (CCT) measurements obtained with all-sky cameras during the COVID-19 lockdown in March 2020 with data from March 2017. Under normal conditions, we expected an increase in night sky brightness (or skyglow, respectively) and CCT because of the transition to LED. This is supported by a measured CCT shift to slightly higher values and a time series analysis of night-time light satellite data showing an increase in artificial light emission in Berlin. However, contrary to this observation, we measured a decrease in artificial skyglow at zenith by 20% at the city center and by more than 50% at 58 km distance from the center during the lockdown. We assume that the main cause for the reduction of artificial skyglow originates from improved air quality due to less air and road traffic, which is supported by statistical data and satellite image analysis. To our knowledge, this is the first reported impact of COVID-19 on artificial skyglow and we conclude that air pollution should shift more into the focus of light pollution research.


2015 ◽  
Vol 370 (1667) ◽  
pp. 20140117 ◽  
Author(s):  
Martin Aubé

Propagation of artificial light at night (ALAN) in the environment is now known to have non negligible consequences on fauna, flora and human health. These consequences depend on light levels and their spectral power distributions, which in turn rely on the efficiency of various physical processes involved in the radiative transfer of this light into the atmosphere and its interactions with the built and natural environment. ALAN can affect the living organisms by direct lighting and indirect lighting (scattered by the sky and clouds and/or reflected by local surfaces). This paper mainly focuses on the behaviour of the indirect light scattered under clear sky conditions. Various interaction processes between anthropogenic light sources and the natural environment are discussed. This work mostly relies on a sensitivity analysis conducted with the light pollution radiative transfer model, Illumina (Aubé et al . 2005 Light pollution modelling and detection in a heterogeneous environment: toward a night-time aerosol optical depth retrieval method. In Proc. SPIE 2005, vol. 5890, San Diego, California, USA). More specifically, the impact of (i) the molecular and aerosol scattering and absorption, (ii) the second order of scattering, (iii) the topography and obstacle blocking, (iv) the ground reflectance and (v) the spectrum of light devices and their angular emission functions are examined. This analysis considers different behaviour as a function of the distance from the city centre, along with different zenith viewing angles in the principal plane.


Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 734
Author(s):  
Mira Van den Broeck ◽  
Raphaël De Cock ◽  
Stefan Van Dongen ◽  
Erik Matthysen

Nocturnal light pollution from anthropogenic origin is increasing worldwide and is recognised as a major threat for nocturnal biodiversity. We studied the impact of artificial light on the mate attraction success of female common glow-worms (Lampyris noctiluca L.) by daily monitoring their glowing status in the field, acting as a proxy for mating status throughout the mating season. We found that females in dark surroundings typically stopped glowing after one night, indicating that they had mated, while females in illuminated areas glowed for significantly more nights, in some cases up to 15 nights. Our study confirms previous findings and hypotheses that females exposed to artificial light suffer from a reduced mate attraction success with a negative impact on populations.


Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 306 ◽  
Author(s):  
Przemyslaw Tabaka ◽  
Pawel Rozga

The article presents the results of the studies concerning the influence of a light source installed in luminaire of opal sphere type on the light pollution effect of the night sky. It is known from literature reports that the effect of light pollution is influenced by the spectral distribution of light. Although the influence of the spectral distribution has been widely studied from different perspectives, there is still a need to study this phenomenon—for example, from the point of view of the spectral reflection properties of the ground, on which the lanterns are installed. Hence, the above-mentioned aspect was considered in the authors’ investigations. The luminaire considered has been equipped with 20 different light sources, including the latest generation of lamps (light-emitting diodes, LEDs) as well as the conventional ones. With respect to these light sources, the measurements of light distribution and spectral distribution of emitted radiation of the luminaire were performed. Having these measurement data, the simulations were carried out using the DIALux software, and the calculations were made using the specially prepared calculation tool. On the basis of the results obtained in this way this was stated that the type of light source installed in the luminaire has a significant effect on the sky glow. An important factor affecting light pollution is not only the value of the luminous flux emitted upward but also the spectral characteristics of the emitted radiation, the impact of which is most noticeable. The conclusions from the studies indicate the next steps in the analysis of the light pollution effect. These steps will be focused on extended analysis of LEDs as modern and developed light sources.


2021 ◽  
Vol 899 (1) ◽  
pp. 012039
Author(s):  
A Papalambrou ◽  
L T Doulos ◽  
G Drakatos ◽  
M Xanthakis ◽  
P Minetos ◽  
...  

Abstract This work describes the preparatory steps for the planning of a light pollution protected area in the form of an International Dark-Sky Park in Aenos National Park at the island of Kefalonia that refer to lighting and light pollution. In more detail, we identified and measured luminance, illuminance and spectrum of public lighting at the island of Kefalonia in areas that are adjacent to the National Park and may influence its operation as a Dark Sky Park. This procedure also includes identifying the luminaire types and light sources, judging their suitability, identifying malpractices and proposing changes. In general, many malpractices were identified both in old lighting installations as well as recent LED retrofits or new installations with more common ones being rich sources in blue light and use of non-cut off luminaires. Light pollution measurements were performed that prove that Aenos National Park has dark enough skies to meet requirements.


Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 812
Author(s):  
Débora Parrine ◽  
Todd M. Greco ◽  
Bilal Muhammad ◽  
Bo-Sen Wu ◽  
Xin Zhao ◽  
...  

Plants pigments, such as chlorophyll and carotenoids, absorb light within specific wavelength ranges, impacting their response to environmental light changes. Although the color-specific response of plants to natural levels of light is well described, extreme high-light stress is still being discussed as a general response, without considering the impact of wavelengths in particular response processes. In this study, we explored how the plant proteome coordinated the response and recovery to extreme light conditions (21,000 µmol m−2 s−1) under different wavelengths. Changes at the protein and mRNA levels were measured, together with the photosynthetic parameters of plants under extreme high-light conditions. The changes in abundance of four proteins involved in photoinhibition, and in the biosynthesis/assembly of PSII (PsbS, PsbH, PsbR, and Psb28) in both light treatments were measured. The blue-light treatment presented a three-fold higher non-photochemical quenching and did not change the level of the oxygen-evolving complex (OEC) or the photosystem II (PSII) complex components when compared to the control, but significantly increased psbS transcripts. The red-light treatment caused a higher abundance of PSII and OEC proteins but kept the level of psbS transcripts the same as the control. Interestingly, the blue light stimulated a more efficient energy dissipation mechanism when compared to the red light. In addition, extreme high-light stress mechanisms activated by blue light involve the role of OEC through increasing PsbS transcript levels. In the proteomics spatial analysis, we report disparate activation of multiple stress pathways under three differently damaged zones as the enriched function of light stress only found in the medium-damaged zone of the red LED treatment. The results indicate that the impact of extreme high-light stress on the proteomic level is wavelength-dependent.


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