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Author (up) Dominy, N.J.; Melin, A.D. url  doi
openurl 
  Title Liminal Light and Primate Evolution Type Journal Article
  Year 2020 Publication Annual Review of Anthropology Abbreviated Journal Annu. Rev. Anthropol.  
  Volume 49 Issue 1 Pages  
  Keywords Primates; Vision; Moonlight; Twilight  
  Abstract The adaptive origins of primates and anthropoid primates are topics of enduring interest to biological anthropologists. A convention in these discussions is to treat the light environment as binary—night is dark, day is light—and to impute corresponding selective pressure on the visual systems and behaviors of primates. In consequence, debate has tended to focus on whether a given trait can be interpreted as evidence of nocturnal or diurnal behavior in the primate fossil record. Such classification elides the variability in light, or the ways that primates internalize light in their environments. Here, we explore the liminality of light by focusing on what it is, its many sources, and its flux under natural conditions. We conclude by focusing on the intensity and spectral properties of twilight, and we review the mounting evidence of its importance as a cue that determines the onset or offset of primate activities as well as the entrainment of circadian rhythms.  
  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 0084-6570 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 3110  
Permanent link to this record
 

 
Author (up) Murugavel, B.; Kelber, A.; Somanathan, H. url  doi
openurl 
  Title Light, flight and the night: effect of ambient light and moon phase on flight activity of pteropodid bats Type Journal Article
  Year 2021 Publication Journal of Comparative Physiology. A, Neuroethology, Sensory, Neural, and Behavioral Physiology Abbreviated Journal J Comp Physiol A Neuroethol Sens Neural Behav Physiol  
  Volume in press Issue Pages  
  Keywords Animals; Moonlight; Ambient light; Flight activity; Moon phases; Pteropodids; Twilight zones  
  Abstract Fruit-feeding pteropodid bats roost under varying light conditions. Some roost in trees with high exposure to daylight (> 1000 lx), while others roost in dark caves (< 0.1 lx). To understand the effect of ambient light intensity and moon phase on flight activity, we examined flight times across five lunar cycles in three pteropodid species whose roosts differ in daylight exposure. We found significant interspecific differences in flight emergence and termination times. All species initiated flights after sunset but Rousettus leschenaultii, which typically roosts in caves, delayed emergence (40 +/- 11 min) more than the two tree-roosting species Pteropus giganteus (16 +/- 6 min) and Cynopterus sphinx (19 +/- 7 min). R. leschenaultii terminated flights earlier (30 +/- 7 min before sunrise) than P. giganteus (11 +/- 11 min) and C. sphinx (16 +/- 10 min). All individuals from P. giganteus and C. sphinx roosts emerged within less than an hour, while emergence times were more spread out in the R. leschenaultii colony. Peak emergence times differed across moon phases in the cave-roosting R. leschenaultii but not in the other species. Flight activity in R. leschenaultii is restricted to comparatively lower light levels than the tree-roosting species. The observed interspecific differences suggest that bat species, sharing same landscapes may respond differently to light pollution.  
  Address IISER TVM Centre for Research and Education in Ecology and Evolution (ICREEE), School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, India  
  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 0340-7594 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:33537858 Approved no  
  Call Number GFZ @ kyba @ Serial 3346  
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Author (up) Spitschan, M.; Aguirre, G.K.; Brainard, D.H.; Sweeney, A.M. url  doi
openurl 
  Title Variation of outdoor illumination as a function of solar elevation and light pollution Type Journal Article
  Year 2016 Publication Scientific Reports Abbreviated Journal Sci Rep  
  Volume 6 Issue Pages 26756  
  Keywords Skyglow; Measurements; light pollution; daylight; twilight; sky brightness; spectral irradiance; CIE  
  Abstract The illumination of the environment undergoes both intensity and spectral changes during the 24 h cycle of a day. Daylight spectral power distributions are well described by low-dimensional models such as the CIE (Commission Internationale de l'Eclairage) daylight model, but the performance of this model in non-daylight regimes is not characterised. We measured downwelling spectral irradiance across multiple days in two locations in North America: One rural location (Cherry Springs State Park, PA) with minimal anthropogenic light sources, and one city location (Philadelphia, PA). We characterise the spectral, intensity and colour changes and extend the existing CIE model for daylight to capture twilight components and the spectrum of the night sky.  
  Address Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA  
  Corporate Author Thesis  
  Publisher Nature Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:27272736 Approved no  
  Call Number IDA @ john @ Serial 1464  
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Author (up) Walmsley, L.; Hanna, L.; Mouland, J.; Martial, F.; West, A.; Smedley, A.R.; Bechtold, D.A.; Webb, A.R.; Lucas, R.J.; Brown, T.M. url  doi
openurl 
  Title Colour As a Signal for Entraining the Mammalian Circadian Clock Type Journal Article
  Year 2015 Publication PLoS Biology Abbreviated Journal PLoS Biol  
  Volume 13 Issue 4 Pages e1002127  
  Keywords Animals; biology; color; circadian disruption; animal models; mouse models; Suprachiasmatic Nucleus; Photoperiod; twilight  
  Abstract Twilight is characterised by changes in both quantity (“irradiance”) and quality (“colour”) of light. Animals use the variation in irradiance to adjust their internal circadian clocks, aligning their behaviour and physiology with the solar cycle. However, it is currently unknown whether changes in colour also contribute to this entrainment process. Using environmental measurements, we show here that mammalian blue-yellow colour discrimination provides a more reliable method of tracking twilight progression than simply measuring irradiance. We next use electrophysiological recordings to demonstrate that neurons in the mouse suprachiasmatic circadian clock display the cone-dependent spectral opponency required to make use of this information. Thus, our data show that some clock neurons are highly sensitive to changes in spectral composition occurring over twilight and that this input dictates their response to changes in irradiance. Finally, using mice housed under photoperiods with simulated dawn/dusk transitions, we confirm that spectral changes occurring during twilight are required for appropriate circadian alignment under natural conditions. Together, these data reveal a new sensory mechanism for telling time of day that would be available to any mammalian species capable of chromatic vision.  
  Address Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom  
  Corporate Author Thesis  
  Publisher PLOS Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1544-9173 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:25884537 Approved no  
  Call Number IDA @ john @ Serial 1152  
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