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Author Kronfeld-Schor, N.; Dominoni, D.; de la Iglesia, H.; Levy, O.; Herzog, E.D.; Dayan, T.; Helfrich-Forster, C.
Title Chronobiology by moonlight Type Journal Article
Year 2013 Publication Proceedings. Biological Sciences / The Royal Society Abbreviated Journal Proc Biol Sci
Volume (down) 280 Issue 1765 Pages 20123088
Keywords Animals; Behavior, Animal/physiology; Circadian Rhythm/physiology; Feeding Behavior/*physiology; Invertebrates/*physiology; *Light; *Moon; Predatory Behavior/physiology; Reproduction/physiology; Vertebrates/physiology; communication; foraging; light pollution; lunar cycle; predation; reproduction
Abstract Most studies in chronobiology focus on solar cycles (daily and annual). Moonlight and the lunar cycle received considerably less attention by chronobiologists. An exception are rhythms in intertidal species. Terrestrial ecologists long ago acknowledged the effects of moonlight on predation success, and consequently on predation risk, foraging behaviour and habitat use, while marine biologists have focused more on the behaviour and mainly on reproduction synchronization with relation to the Moon phase. Lately, several studies in different animal taxa addressed the role of moonlight in determining activity and studied the underlying mechanisms. In this paper, we review the ecological and behavioural evidence showing the effect of moonlight on activity, discuss the adaptive value of these changes, and describe possible mechanisms underlying this effect. We will also refer to other sources of night-time light ('light pollution') and highlight open questions that demand further studies.
Address Department of Zoology, Tel Aviv University, Tel Aviv 69978, Israel. nogaks@tauex.tau.ac.il
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0962-8452 ISBN Medium
Area Expedition Conference
Notes PMID:23825199; PMCID:PMC3712431 Approved no
Call Number IDA @ john @ Serial 29
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Author Haag, C.R.; Riek, M.; Hottinger, J.W.; Pajunen, V.I.; Ebert, D.
Title Genetic diversity and genetic differentiation in Daphnia metapopulations with subpopulations of known age Type Journal Article
Year 2005 Publication Genetics Abbreviated Journal Genetics
Volume (down) 170 Issue 4 Pages 1809-1820
Keywords Plants; Aging; Animals; Daphnia/*genetics/*physiology; *Genetic Variation; *Genetics, Population
Abstract If colonization of empty habitat patches causes genetic bottlenecks, freshly founded, young populations should be genetically less diverse than older ones that may have experienced successive rounds of immigration. This can be studied in metapopulations with subpopulations of known age. We studied allozyme variation in metapopulations of two species of water fleas (Daphnia) in the skerry archipelago of southern Finland. These populations have been monitored since 1982. Screening 49 populations of D. longispina and 77 populations of D. magna, separated by distances of 1.5-2180 m, we found that local genetic diversity increased with population age whereas pairwise differentiation among pools decreased with population age. These patterns persisted even after controlling for several potentially confounding ecological variables, indicating that extinction and recolonization dynamics decrease local genetic diversity and increase genetic differentiation in these metapopulations by causing genetic bottlenecks during colonization. We suggest that the effect of these bottlenecks may be twofold, namely decreasing genetic diversity by random sampling and leading to population-wide inbreeding. Subsequent immigration then may not only introduce new genetic material, but also lead to the production of noninbred hybrids, selection for which may cause immigrant alleles to increase in frequency, thus leading to increased genetic diversity in older populations.
Address Unite d'Ecologie et d'Evolution, Departement de Biologie, Universite de Fribourg, CH-1700 Fribourg, Switzerland. christoph.haag@ed.ac.uk
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 0016-6731 ISBN Medium
Area Expedition Conference
Notes PMID:15937138; PMCID:PMC1449778 Approved no
Call Number LoNNe @ kagoburian @ Serial 660
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Author Jetz, W.; Steffen, J.; Linsenmair, K.E.
Title Effects of light and prey availability on nocturnal, lunar and seasonal activity of tropical nightjars Type Journal Article
Year 2003 Publication Oikos Abbreviated Journal Oikos
Volume (down) 103 Issue 3 Pages 627-639
Keywords foraging; Caprimulgus climacurus; birds; nightjars; standard-winged nightjar; Macrodipteryx longipennis; long-tailed nightjar
Abstract Nightjars and their allies represent the only major group of visually hunting aerial insectivores with a crepuscular and/or nocturnal lifestyle. Our purpose was to examine how both light regime and prey abundance in the tropics, where periods of twilight are extremely short, but nightjar diversity is high, affect activity across different temporal scales. We studied two nightjar species in West African bush savannah, standard-winged nightjars Macrodipteryx longipennis Shaw and long-tailed nightjars Caprimulgus climacurus Vieillot. We measured biomass of potential prey available using a vehicle mounted trap and found that it was highest at dusk and significantly lower at dawn and during the night. Based on direct observations, both nightjars exhibit the most intense foraging behaviour at dusk, less intense foraging at dawn and least at night, as predicted by both prey abundance and conditions for visual prey detection. Nocturnal foraging was positively correlated with lunar light levels and ceased below about 0.03 mW m−2. Over the course of a lunar cycle, nocturnal light availability varied markedly, while prey abundance remained constant at dusk and at night was slightly higher at full moon. Both species increased twilight foraging activity during new moon periods, compensating for the shorter nocturnal foraging window at that time. Seasonally, the pattern of nocturnal light availability was similar throughout the year, while prey availability peaked shortly after onset of the wet season and then slowly decreased over the following four months. The courtship and breeding phenology of both species was timed to coincide with the peak in aerial insect abundance, suggesting that prey availability rather than direct abiotic factors act as constraints, at least at the seasonal level. Our findings illustrate the peculiar constraints on visually orienting aerial nocturnal insectivores in general and tropical nightjars in particular and highlight the resulting nocturnal, lunar and seasonal allocation of activities.
Address
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0030-1299 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 48
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Author Prugh, L.R.; Golden, C.D.
Title Does moonlight increase predation risk? Meta-analysis reveals divergent responses of nocturnal mammals to lunar cycles Type Journal Article
Year 2013 Publication The Journal of Animal Ecology Abbreviated Journal J Anim Ecol
Volume (down) 83 Issue 2 Pages 504-514
Keywords foraging efficiency; giving-up density; illumination; indirect effects; lunar cycles; moonlight; nocturnality; phylogenetic meta-analysis; predation risk; risk-sensitive foraging
Abstract The risk of predation strongly affects mammalian population dynamics and community interactions. Bright moonlight is widely believed to increase predation risk for nocturnal mammals by increasing the ability of predators to detect prey, but the potential for moonlight to increase detection of predators and the foraging efficiency of prey has largely been ignored. Studies have reported highly variable responses to moonlight among species, calling into question the assumption that moonlight increases risk. Here, we conducted a quantitative meta-analysis examining the effects of moonlight on the activity of 59 nocturnal mammal species to test the assumption that moonlight increases predation risk. We examined patterns of lunarphilia and lunarphobia across species in relation to factors such as trophic level, habitat cover preference and visual acuity. Across all species included in the meta-analysis, moonlight suppressed activity. The magnitude of suppression was similar to the presence of a predator in experimental studies of foraging rodents (13.6% and 18.7% suppression, respectively). Contrary to the expectation that moonlight increases predation risk for all prey species, however, moonlight effects were not clearly related to trophic level and were better explained by phylogenetic relatedness, visual acuity and habitat cover. Moonlight increased the activity of prey species that use vision as their primary sensory system and suppressed the activity of species that primarily use other senses (e.g. olfaction, echolocation), and suppression was strongest in open habitat types. Strong taxonomic patterns underlay these relationships: moonlight tended to increase primate activity, whereas it tended to suppress the activity of rodents, lagomorphs, bats and carnivores. These results indicate that visual acuity and habitat cover jointly moderate the effect of moonlight on predation risk, whereas trophic position has little effect. While the net effect of moonlight appears to increase predation risk for most nocturnal mammals, our results highlight the importance of sensory systems and phylogenetic history in determining the level of risk.
Address Institute of Arctic Biology, University of Alaska Fairbanks, 311 Irving 1, Fairbanks, AK, 99775, USA
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8790 ISBN Medium
Area Expedition Conference
Notes PMID:24102189 Approved no
Call Number IDA @ john @ Serial 83
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Author Dwyer, R.G.; Bearhop, S.; Campbell, H.A.; Bryant, D.M.
Title Shedding light on light: benefits of anthropogenic illumination to a nocturnally foraging shorebird Type Journal Article
Year 2013 Publication The Journal of Animal Ecology Abbreviated Journal J Anim Ecol
Volume (down) 82 Issue 2 Pages 478-485
Keywords Artificial light; Dmsp/Ols; foraging strategy; moonlight; shorebirds; birds; animals; foraging; Tringa totanus; common redshank
Abstract Intertidal habitats provide important feeding areas for migratory shorebirds. Anthropogenic developments along coasts can increase ambient light levels at night across adjacent inter-tidal zones. Here, we report the effects of elevated nocturnal light levels upon the foraging strategy of a migratory shorebird (common redshank Tringa totanus) overwintering on an industrialised estuary in Northern Europe. To monitor behaviour across the full intertidal area, individuals were located by day and night using VHF transmitters, and foraging behaviour was inferred from inbuilt posture sensors. Natural light was scored using moon-phase and cloud cover information and nocturnal artificial light levels were obtained using geo-referenced DMSP/OLS night-time satellite imagery at a 1-km resolution. Under high illumination levels, the commonest and apparently preferred foraging behaviour was sight-based. Conversely, birds feeding in areas with low levels of artificial light had an elevated foraging time and fed by touch, but switched to visual rather than tactile foraging behaviour on bright moonlit nights in the absence of cloud cover. Individuals occupying areas which were illuminated continuously by lighting from a large petrochemical complex invariably exhibited a visually based foraging behaviour independently of lunar phase and cloud cover. We show that ambient light levels affect the timing and distribution of foraging opportunities for redshank. We argue that light emitted from an industrial complex improved nocturnal visibility. This allowed sight-based foraging in place of tactile foraging, implying both a preference for sight-feeding and enhanced night-time foraging opportunities under these conditions. The study highlights the value of integrating remotely sensed data and telemetry techniques to assess the effect of anthropogenic change upon nocturnal behaviour and habitat use.
Address Centre for Ecology and Conservation, School of Biosciences, University of Exeter, Cornwall Campus, Penryn, Cornwall, TR10 9EZ, UK
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 0021-8790 ISBN Medium
Area Expedition Conference
Notes PMID:23190422 Approved no
Call Number IDA @ john @ Serial 44
Permanent link to this record