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Author Kempenaers, B.; Borgstrom, P.; Loes, P.; Schlicht, E.; Valcu, M.
Title Artificial night lighting affects dawn song, extra-pair siring success, and lay date in songbirds Type Journal Article
Year 2010 Publication Current Biology : CB Abbreviated Journal Curr Biol
Volume 20 Issue 19 Pages 1735-1739
Keywords Animals; Environmental Pollution; Female; Light; *Lighting; Male; *Reproduction; Sexual Behavior, Animal/*physiology; Songbirds/*physiology; Time Factors; *Vocalization, Animal
Abstract Associated with a continued global increase in urbanization, anthropogenic light pollution is an important problem. However, our understanding of the ecological consequences of light pollution is limited. We investigated effects of artificial night lighting on dawn song in five common forest-breeding songbirds. In four species, males near street lights started singing significantly earlier at dawn than males elsewhere in the forest, and this effect was stronger in naturally earlier-singing species. We compared reproductive behavior of blue tits breeding in edge territories with and without street lights to that of blue tits breeding in central territories over a 7 year period. Under the influence of street lights, females started egg laying on average 1.5 days earlier. Males occupying edge territories with street lights were twice as successful in obtaining extra-pair mates than their close neighbors or than males occupying central forest territories. Artificial night lighting affected both age classes but had a stronger effect on yearling males. Our findings indicate that light pollution has substantial effects on the timing of reproductive behavior and on individual mating patterns. It may have important evolutionary consequences by changing the information embedded in previously reliable quality-indicator traits.
Address Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Eberhard-Gwinner-Strasse, 82319 Seewiesen, Germany. b.kempenaers@orn.mpg.de
Corporate Author Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0960-9822 ISBN Medium
Area Expedition Conference
Notes PMID:20850324 Approved no
Call Number IDA @ john @ Serial 51
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Author Rockhill, A.P.; DePerno, C.S.; Powell, R.A.
Title The effect of illumination and time of day on movements of bobcats (Lynx rufus) Type Journal Article
Year 2013 Publication PloS one Abbreviated Journal PLoS One
Volume 8 Issue 7 Pages e69213
Keywords Animals; Female; *Lighting; Lynx/*physiology; Male; Moon; Movement/*physiology; North Carolina; Time Factors; Wetlands
Abstract Understanding behavioral changes of prey and predators based on lunar illumination provides insight into important life history, behavioral ecology, and survival information. The objectives of this research were to determine if bobcat movement rates differed by period of day (dark, moon, crepuscular, day), lunar illumination (<10%, 10 – <50%, 50 – <90%, >90%), and moon phase (new, full). Bobcats had high movement rates during crepuscular and day periods and low movement rates during dark periods with highest nighttime rates at 10-<50% lunar illumination. Bobcats had highest movement rates during daytime when nighttime illumination was low (new moon) and higher movement rates during nighttime when lunar illumination was high (full moon). The behaviors we observed are consistent with prey availability being affected by light level and by limited vision by bobcats during darkness.
Address Fisheries, Wildlife, and Conservation Biology, North Carolina State University, Raleigh, North Carolina, USA. aimee_rockhill@ncsu.edu
Corporate Author Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-6203 ISBN Medium
Area Expedition Conference
Notes PMID:23861963; PMCID:PMC3704646 Approved no
Call Number IDA @ john @ Serial 84
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Author Raiewski, E.E.; Elliott, J.A.; Evans, J.A.; Glickman, G.L.; Gorman, M.R.
Title Twice daily melatonin peaks in Siberian but not Syrian hamsters under 24 h light:dark:light:dark cycles Type Journal Article
Year 2012 Publication Chronobiology International Abbreviated Journal Chronobiol Int
Volume 29 Issue 9 Pages 1206-1215
Keywords Animals; Circadian Rhythm/*physiology; Cricetinae; Male; Melatonin/blood/*secretion; Mesocricetus/blood/*physiology; Motor Activity/physiology; Phodopus/blood/*physiology; Photoperiod; Species Specificity
Abstract The daily pattern of blood-borne melatonin varies seasonally under the control of a multi-oscillator circadian pacemaker. Here we examine patterns of melatonin secretion and locomotor activity in Siberian and Syrian hamsters entrained to bimodal LDLD8:4:8:4 and LD20:4 lighting schedules that facilitate novel temporal arrangements of component circadian oscillators. Under LDLD, both species robustly bifurcated wheel-running activity in distinct day scotophase (DS) and night scotophase (NS) bouts. Siberian hamsters displayed significant melatonin increases during each scotophase in LDLD, and in the single daily scotophase of LD20:4. The bimodal melatonin secretion pattern persisted in acutely extended 16 h scotophases. Syrian hamsters, in contrast, showed no significant increases in plasma melatonin during either scotophase of LDLD8:4:8:4 or in LD20:4. In this species, detectable levels were observed only when the DS of LDLD was acutely extended to yield 16 h of darkness. Established species differences in the phase lag of nocturnal melatonin secretion relative to activity onset may underlie the above contrast: In non-bifurcated entrainment to 24 h LD cycles, Siberian hamsters show increased melatonin secretion within approximately 2 h after activity onset, whereas in Syrian hamsters, detectable melatonin secretion phase lags activity onset and the L/D transition by at least 4 h. The present results provide new evidence indicating multi-oscillator regulation of the waveform of melatonin secretion, specifically, the circadian control of the onset, offset and duration of nocturnal secretion.
Address Department of Psychology, and Center for Chronobiology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0109, USA. eraiewski@ucsd.edu
Corporate Author Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0742-0528 ISBN Medium
Area Expedition Conference
Notes PMID:23003567 Approved no
Call Number IDA @ john @ Serial 85
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Author Evans, J.A.; Carter, S.N.; Freeman, D.A.; Gorman, M.R.
Title Dim nighttime illumination alters photoperiodic responses of hamsters through the intergeniculate leaflet and other photic pathways Type Journal Article
Year 2012 Publication Neuroscience Abbreviated Journal Neuroscience
Volume 202 Issue Pages 300-308
Keywords Animals; Biological Clocks/physiology; Circadian Rhythm/physiology; Cricetinae; Darkness; Data Interpretation, Statistical; Geniculate Bodies/*physiology; *Lighting; Male; Motor Activity/physiology; Phodopus; *Photoperiod; Visual Pathways/*physiology
Abstract In mammals, light entrains the central pacemaker within the suprachiasmatic nucleus (SCN) through both a direct neuronal projection from the retina and an indirect projection from the intergeniculate leaflet (IGL) of the thalamus. Although light comparable in intensity to moonlight is minimally effective at resetting the phase of the circadian clock, dimly lit and completely dark nights are nevertheless perceived differentially by the circadian system, even when nighttime illumination is below putative thresholds for phase resetting. Under a variety of experimental paradigms, dim nighttime illumination exerts effects that may be characterized as enhancing the plasticity of circadian entrainment. For example, relative to completely dark nights, dimly lit nights accelerate development of photoperiodic responses of Siberian hamsters transferred from summer to winter day lengths. Here we assess the neural pathways underlying this response by testing whether IGL lesions eliminate the effects of dim nighttime illumination under short day lengths. Consistent with previous work, dimly lit nights facilitated the expansion of activity duration under short day lengths. Ablation of the IGL, moreover, did not influence photoperiodic responses in animals held under completely dark nights. However, among animals that were provided dimly lit nights, IGL lesions prevented the short-day typical expansion of activity duration as well as the seasonally appropriate gonadal regression and reduction in body weight. Thus, the present data indicate that the IGL plays a central role in mediating the facilitative effects of dim nighttime illumination under short day lengths, but in the absence of the IGL, dim light at night influences photoperiodic responses through residual photic pathways.
Address Department of Psychology, University of California, San Diego, La Jolla, CA, USA. jevans@msm.edu
Corporate Author Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0306-4522 ISBN Medium
Area Expedition Conference
Notes PMID:22155265; PMCID:PMC3578228 Approved no
Call Number IDA @ john @ Serial 87
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Author Fonken, L.K.; Kitsmiller, E.; Smale, L.; Nelson, R.J.
Title Dim nighttime light impairs cognition and provokes depressive-like responses in a diurnal rodent Type Journal Article
Year 2012 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms
Volume 27 Issue 4 Pages 319-327
Keywords Analysis of Variance; Animals; CA1 Region, Hippocampal/cytology; CA3 Region, Hippocampal/cytology; Circadian Rhythm/*physiology; Cognition/*physiology/radiation effects; Corticosterone/blood; Dendrites/physiology/radiation effects; Dentate Gyrus/cytology; Depressive Disorder/*physiopathology; Food Preferences/physiology/radiation effects; Light; Male; Maze Learning/physiology/radiation effects; Motor Activity/physiology/radiation effects; Murinae/*physiology; Neurons/drug effects/physiology; *Photoperiod; Swimming/physiology
Abstract Circadian disruption is a common by-product of modern life. Although jet lag and shift work are well-documented challenges to circadian organization, many more subtle environmental changes cause circadian disruption. For example, frequent fluctuations in the timing of the sleep/wake schedule, as well as exposure to nighttime lighting, likely affect the circadian system. Most studies of these effects have focused on nocturnal rodents, which are very different from diurnal species with respect to their patterns of light exposure and the effects that light can have on their activity. Thus, the authors investigated the effect of nighttime light on behavior and the brain of a diurnal rodent, the Nile grass rat. Following 3 weeks of exposure to standard light/dark (LD; 14:10 light [~150 lux] /dark [0 lux]) or dim light at night (dLAN; 14:10 light [~150 lux] /dim [5 lux]), rats underwent behavioral testing, and hippocampal neurons within CA1, CA3, and the dentate gyrus (DG) were examined. Three behavioral effects of dLAN were observed: (1) decreased preference for a sucrose solution, (2) increased latency to float in a forced swim test, and (3) impaired learning and memory in the Barnes maze. Light at night also reduced dendritic length in DG and basilar CA1 dendrites. Dendritic length in the DG positively correlated with sucrose consumption in the sucrose anhedonia task. Nighttime light exposure did not disrupt the pattern of circadian locomotor activity, and all grass rats maintained a diurnal activity pattern. Together, these data suggest that exposure to dLAN can alter affective responses and impair cognition in a diurnal animal.
Address Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA. fonken.1@osu.edu
Corporate Author Thesis
Publisher (down) Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0748-7304 ISBN Medium
Area Expedition Conference
Notes PMID:22855576 Approved no
Call Number IDA @ john @ Serial 91
Permanent link to this record