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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
Publisher (up) Place of Publication Editor
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
Publisher (up) Place of Publication Editor
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 Rotics, S.; Dayan, T.; Kronfeld-Schor, N.
Title Effect of artificial night lighting on temporally partitioned spiny mice Type Journal Article
Year 2011 Publication Journal of Mammalogy Abbreviated Journal Journal of Mammalogy
Volume 92 Issue 1 Pages 159-168
Keywords mice; animals; mammals; Acomys cahirinus; Acomys russatus; activity patterns; light night niche; light pollution
Abstract We studied the effect of ecological light pollution on a rocky desert community, focusing on 2 spiny mouse congeners, nocturnal Acomys cahirinus (common spiny mouse) and diurnal Acomys russatus (golden spiny mouse). We hypothesized that in response to artificial illumination A. cahirinus will decrease its activity and A. russatus will increase its activity, and thus temporal overlap and interspecific competition could increase. Our study took place in 4 field enclosures: the 1st and 3rd months were controls with natural light, and in the 2nd month artificial illumination, simulating low levels of light pollution, was set for the first 3 h of the night. We implanted temperature-sensitive radiotransmitters to monitor mouse activity, and individual identification tags with automonitored foraging patches were used to track foraging behavior. A. cahirinus decreased activity and foraging with artificial lighting, restricting movement particularly in less-sheltered microhabitats, probably because of increased predation risk. Because illumination restricted both activity time and space, intraspecific encounters of A. cahirinus over foraging patches increased during and following the illuminated hours. However, diurnal A. russatus did not expand its activity into the illuminated hours, possibly due to the presence of competing A. cahirinus, or to nonfavorable environmental conditions. Therefore, overt interspecific competition was not affected by experimental light pollution. Light pollution had a negative influence by reducing overall activity and producing a relatively underexploited temporal niche, which may promote invasion of alien species that are less light sensitive; and by increasing intraspecific overlap in foraging A. cahirinus.
Address
Corporate Author Thesis
Publisher (up) Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2372 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 86
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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
Publisher (up) Place of Publication Editor
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 Topping, M.G.; Millar, J.S.; Goddard, J.A.
Title The effects of moonlight on nocturnal activity in bushy-tailed wood rats (Neotoma cinerea) Type Journal Article
Year 1999 Publication Canadian Journal of Zoology Abbreviated Journal Can. J. Zool.
Volume 77 Issue 3 Pages 480-485
Keywords animals; mammals; rats; bushy-tailed wood rat; Neotoma cinerea; Canada; foraging; reproduction; moonlight; predation risk
Abstract The nocturnal activity of bushy-tailed wood rats (Neotoma cinerea) was monitored for two breeding seasons (1993 and 1994) in the Canadian Rockies. Radiotelemetry was used under three levels of moonlight to assess two measures of nocturnal activity: (i) the proportion of animals crossing rocky outcrops and entering the surrounding forest to forage, search for mates, or both, and (ii) the distance moved from the den site while in the forest. Males and females exhibited significant differences among moonlight levels, with greater activity on nights of intermediate-level moonlight and less activity on nights with bright or dark moonlight. There was no difference in the proportions of males and females active at any moonlight level. The distances moved from the den did not differ among moonlight levels for either males or females. Having traversed the rocks and entered the forest, individuals moved similar distances regardless of light level. These results suggest that wood rats respond to moonlight only when making the decision to cross rocks and enter the forest. This behaviour presumably serves to counteract the increased risk of predation on bright nights.
Address
Corporate Author Thesis
Publisher (up) Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-4301 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 88
Permanent link to this record