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Author Dominoni, D.M.; Helm, B.; Lehmann, M.; Dowse, H.B.; Partecke, J.
Title Clocks for the city: circadian differences between forest and city songbirds Type Journal Article
Year 2013 Publication Proceedings. Biological Sciences / The Royal Society Abbreviated Journal Proc Biol Sci
Volume 280 Issue (up) 1763 Pages 20130593
Keywords Animals; Circadian Clocks/*physiology; Circadian Rhythm; Cities; *Ecosystem; Light; Male; Songbirds/classification/*physiology; Trees; Urbanization; birds; chronotype; circadian rhythms; light at night; radio-telemetry; urbanization
Abstract To keep pace with progressing urbanization organisms must cope with extensive habitat change. Anthropogenic light and noise have modified differences between day and night, and may thereby interfere with circadian clocks. Urbanized species, such as birds, are known to advance their activity to early morning and night hours. We hypothesized that such modified activity patterns are reflected by properties of the endogenous circadian clock. Using automatic radio-telemetry, we tested this idea by comparing activity patterns of free-living forest and city European blackbirds (Turdus merula). We then recaptured the same individuals and recorded their activity under constant conditions. City birds started their activity earlier and had faster but less robust circadian oscillation of locomotor activity than forest conspecifics. Circadian period length predicted start of activity in the field, and this relationship was mainly explained by fast-paced and early-rising city birds. Although based on only two populations, our findings point to links between city life, chronotype and circadian phenotype in songbirds, and potentially in other organisms that colonize urban habitats, and highlight that urban environments can significantly modify biologically important rhythms in wild organisms.
Address Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, Radolfzell 78479, Germany. ddominoni@orn.mpg.de
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 0962-8452 ISBN Medium
Area Expedition Conference
Notes PMID:23740778; PMCID:PMC3774226 Approved no
Call Number IDA @ john @ Serial 42
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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 280 Issue (up) 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
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 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 Stokkan, K.-A.; Folkow, L.; Dukes, J.; Neveu, M.; Hogg, C.; Siefken, S.; Dakin, S.C.; Jeffery, G.
Title Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer Type Journal Article
Year 2013 Publication Proceedings. Biological Sciences Abbreviated Journal Proc Biol Sci
Volume 280 Issue (up) 1773 Pages 20132451
Keywords Animals; Skyglow
Abstract Arctic reindeer experience extreme changes in environmental light from continuous summer daylight to continuous winter darkness. Here, we show that they may have a unique mechanism to cope with winter darkness by changing the wavelength reflection from their tapetum lucidum (TL). In summer, it is golden with most light reflected back directly through the retina, whereas in winter it is deep blue with less light reflected out of the eye. The blue reflection in winter is associated with significantly increased retinal sensitivity compared with summer animals. The wavelength of reflection depends on TL collagen spacing, with reduced spacing resulting in shorter wavelengths, which we confirmed in summer and winter animals. Winter animals have significantly increased intra-ocular pressure, probably produced by permanent pupil dilation blocking ocular drainage. This may explain the collagen compression. The resulting shift to a blue reflection may scatter light through photoreceptors rather than directly reflecting it, resulting in elevated retinal sensitivity via increased photon capture. This is, to our knowledge, the first description of a retinal structural adaptation to seasonal changes in environmental light. Increased sensitivity occurs at the cost of reduced acuity, but may be an important adaptation in reindeer to detect moving predators in the dark Arctic winter.
Address Department of Arctic and Marine Biology, University of Tromso, , Tromso, Norway, Institute of Ophthalmology, University College London, , 11-43 Bath Street, London EC1V 9EL, UK, Moorfields Eye Hospital, , London, 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 0962-8452 ISBN Medium
Area Expedition Conference
Notes PMID:24174115; PMCID:PMC3826237 Approved no
Call Number LoNNe @ kyba @ Serial 1636
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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 82 Issue (up) 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
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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 83 Issue (up) 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
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:24102189 Approved no
Call Number IDA @ john @ Serial 83
Permanent link to this record