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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 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.
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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
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Author Jong, M. de; Eertwegh, L. van den; Beskers, R.E.; Vries, P.P. de; Spoelstra, K.; Visser, M.E.
Title Timing of Avian Breeding in an Urbanised World Type Journal Article
Year 2018 Publication Ardea Abbreviated Journal Ardea
Volume 106 Issue 1 Pages 31-38
Keywords Animals
Abstract A large part of the world is urbanised, and the process of urbanisation is ongoing. This causes dramatic alterations of species' habitat such as increased night light, sound levels and temperature, along with direct disturbance by human activity. We used eight years of citizen science data from ten common bird species breeding in nest boxes throughout The Netherlands to study the relationship between urbanisation and a key life history trait, timing of breeding. We used nightly light levels in the form of sky brightness and light emission as a proxy for urbanisation as the dramatic change of the night-time environment is a prominent effect of urbanisation. We expected birds to lay earlier in areas with more light at night, i.e. in more urbanised areas. We found, however, no relationship between light levels and seasonal timing in the ten species studied. A limitation of our study is that there was only limited data for the areas that were urbanised most (e.g. inside cities). Most nest box study areas are located in areas with a limited level of urbanisation, and hence with relatively low light levels of light at night. The lack of data on breeding birds in more urbanised environments, which is a rapidly expanding habitat for an increasing number of species worldwide, should be the focus of attention and citizen science would be highly suitable to also provide data for such areas.
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0373-2266 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1893
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Author Aubé, M.; Simoneau, A.; Wainscoat, R.; Nelson, L.
Title Modeling the effects of phosphor converted LED lighting to the night sky of the Haleakala Observatory, Hawaii Type Journal Article
Year 2018 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 478 Issue 2 Pages 1776-1783
Keywords Skyglow
Abstract The goal of this study is to evaluate the current level of light pollution in the night sky at the Haleakala Observatory on the island of Maui in Hawaii. This is accomplished with a numerical model that was tested in the first International Dark Sky Reserve located in Mont-Mégantic National Park in Canada. The model uses ground data on the artificial light sources present in the region of study, geographical data, and remotely sensed data for: 1) the nightly upward radiance; 2) the terrain elevation; and, 3) the ground spectral reflectance of the region. The results of the model give a measure of the current state of the sky spectral radiance at the Haleakala Observatory. Then, using the current state as a reference point, multiple light conversion plans are elaborated and evaluated using the model. We can thus estimate the expected impact of each conversion plan on the night sky radiance spectrum. A complete conversion to white (LEDs) with (CCT) of 4000K and 3000K are contrasted with a conversion using (PC) amber (LEDs). We include recommendations concerning the street lamps to be used in sensitive areas like the cities of Kahului and Kihei and suggest best lighting practices related to the color of lamps used at night.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1907
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Author Bouroussis, C.A.; Topalis, F.V.
Title The effect of the spectral response of measurement instruments in the assessment of night sky brightness Type Journal Article
Year 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer
Volume 216 Issue Pages 56-69
Keywords Skyglow; Instrumentation
Abstract This paper deals with the errors and uncertainties in skyglow measurements caused by the variation of sky's spectrum. It considers the theoretical spectral response of common instruments that are used for light pollution assessment. Various types of light sources were used in this investigation. This study calculates the spectral mismatch errors and the corresponding correction factors for each combination of instrument and light source. The calculation method is described and the results are presented in multiple figures. Calculated data show a big variation in potential errors that can be introduced when comparing readings of diverse instruments without considering the sky spectrum variation. This makes the spectral data of the sky a mandatory input to the dark sky assessment. Useful conclusions, related to instruments with better or worse behaviour, are derived from the calculations. The paper also includes suggestions on how to conduct multi-instrument measurements with or without spectral data.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4073 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1908
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Author Wang, L.; Liu, X.; Liu, Z.; Wang, X.; Lei, C.; Zhu, F.
Title Members of the neuropeptide transcriptional network in Helicoverpa armigera and their expression in response to light stress Type Journal Article
Year 2018 Publication Gene Abbreviated Journal Gene
Volume 671 Issue Pages 67-77
Keywords Animals
Abstract Neuropeptides and peptide hormones play central roles in the regulation of various types of insect physiology and behavior. Artificial light at night, a form of environmental stress, has recently been regarded as a source of light stress on nocturnal insects. Because related genomic information is not available, molecular biological studies on the response of neuropeptides in nocturnal insects to light stress are limited. Based on the de novo sequencing of the Helicoverpa armigera head transcriptome, we obtained 124,960 unigenes. Of these, the number of unigenes annotated as neuropeptides and peptide hormones, neurotransmitter precursor processing enzymes, and neurotransmitter receptors were 34, 17, and 58, respectively. Under light stress, there were sex-specific differences in gene expression measured by qRT-PCR. The IMFamide, leucokinin and sNPF genes were differentially expressed at the mRNA level in males but not in females in response to light stress. The results provide new insights on the diversity of the neuropeptide transcriptional network of H. armigera. In addition, some neuropeptides exhibited sex-specific differential expression in response to light stress. Taken collectively, these results not only expand the catalog of known insect neuropeptides but also provide a framework for future functional studies on the physiological roles they play in the light stress response behavior of nocturnal moths.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0378-1119 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1910
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