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Author Wiltschko, W.; Munro, U.; Ford, H.; Wiltschko, R.
Title Red light disrupts magnetic orientation of migratory birds Type Journal Article
Year 1993 Publication Nature Abbreviated Journal Nature
Volume 364 Issue 6437 Pages 525-527
Keywords magnetoreception; birds; animals
Abstract The transduction mechanisms and the neurophysiological basis of magnetoreception in birds are still largely unexplained, even though the role of the magnetic compass in the orientation of birds is fairly well understood. The discussion on magnetoreception in birds and terrestrial vertebrates focuses mainly on two mechanisms: small particles of magnetite and biochemical bi-radical reactions of excited macromolecules. When the bi-radical hypothesis was first proposed, magnetic resonance phenomena in the retina were suggested as the primary processes, which led to the question of whether magnetoreception was light-dependent. Homing experiments and electrophysiological evidence from pigeons have produced evidence consistent with such a mechanism. An effect of the spectral composition of light on magnetic compass orientation in amphibians has recently been described: under blue light of 450 nm and below, newts oriented as they did under the full spectrum, whereas they showed a roughly 90° counterclockwise shift when tested under wavelengths at or above 500 nm. Here we report the first orientation tests on migratory birds under light of different wavelengths; the results suggest a light-dependent process that appears to differ from that reported in newts.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-0836 ISBN Medium
Area Expedition Conference
Notes Approved (down) no
Call Number IDA @ john @ Serial 58
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Author Smit, B.; Boyles, J.G.; Brigham, R.M.; McKechnie, A.E.
Title Torpor in dark times: patterns of heterothermy are associated with the lunar cycle in a nocturnal bird Type Journal Article
Year 2011 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms
Volume 26 Issue 3 Pages 241-248
Keywords Animals; *Biological Clocks; Birds/*physiology; *Body Temperature Regulation; Ecosystem; *Feeding Behavior; Insects; *Moon; Seasons; South Africa
Abstract Many studies have shown that endotherms become more heterothermic when the costs of thermoregulation are high and/or when limited energy availability constrains thermoregulatory capacity. However, the roles of many ecological variables, including constraints on foraging opportunities and/or success, remain largely unknown. To test the prediction that thermoregulatory patterns should be related to foraging opportunities in a heterothermic endotherm, we examined the relationship between the lunar cycle and heterothermy in Freckled Nightjars (Caprimulgus tristigma), which are visually orienting, nocturnal insectivores that are dependent on ambient light to forage. This model system provides an opportunity to assess whether variation in foraging opportunities influences the expression of heterothermy. The nightjars were active and foraged for insects when moonlight was available but became inactive and heterothermic in the absence of moonlight. Lunar illumination was a much stronger predictor of the magnitude of heterothermic responses than was air temperature (T(a)). Our data suggest that heterothermy was strongly related to variation in foraging opportunities associated with the lunar cycle, even though food abundance appeared to remain relatively high throughout the study period. Patterns of thermoregulation in this population of Freckled Nightjars provide novel insights into the environmental and ecological determinants of heterothermy, with the lunar cycle, and not T(a), being the strongest predictor of torpor use.
Address DST/NRF Centre of Excellence at the Percy FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa. smitbe@gmail.com
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 0748-7304 ISBN Medium
Area Expedition Conference
Notes PMID:21628551 Approved (down) no
Call Number IDA @ john @ Serial 59
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Author Troy, J.R.; Holmes, N.D.; Green, M.C.
Title Modeling artificial light viewed by fledgling seabirds Type Journal Article
Year 2011 Publication Ecosphere Abbreviated Journal Ecosphere
Volume 2 Issue 10 Pages art109
Keywords artificial light; fallout; Hydrobatidae; modeling; Newell's Shearwater; Procellariidae; Puffinus newelli; birds
Abstract Artificial light is increasing in coverage across the surface of our planet, impacting the behavioral ecology of many organisms. Attraction to sources of artificial light is a significant threat to certain fledgling shearwaters, petrels (Procellariidae), and storm-petrels (Hydrobatidae) on their first nocturnal flights to the sea. Disorientation by light can cause these birds to crash into vegetation or manmade structures, potentially resulting in death from physical injury, starvation, dehydration, predation by introduced predators, or collisions with vehicles. We developed a GIS-based method to model the intensity of artificial light that fledgling procellariids and hydrobatids could view en route to the ocean (to estimate the degree of threat that artificial light poses to these birds) and present two models for the island of Kauai as examples. These models are particularly relevant to the federally threatened Newell's Shearwater, or `A`o (Puffinus newelli), of which >30,000 fledglings have been collected in response to disorientation by lights on Kauai during the past 30 years. Our models suggest that there are few to no portions of Kauai from which young birds could fledge and not view light on their post-natal nocturnal flights, which is concerning given evidence of a Newell's Shearwater population decline. In future work using this technique, night light intensity layers could be altered to model the effects of modified coastal light conditions on known and potential procellariid and hydrobatid breeding locations. Furthermore, certain methods presented herein may be applicable to other seabirds and additional taxa in which attraction to anthropogenic light poses a serious threat, including migratory passerines and hatchling marine turtles. Components of this modeling approach could potentially be used to spatially estimate effects of other point-source threats to ecological systems, including sound and air pollution.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2150-8925 ISBN Medium
Area Expedition Conference
Notes Approved (down) no
Call Number IDA @ john @ Serial 60
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Author Canário, F.; Hespanhol Leitão, A.; Tomé, R.
Title Predation Attempts by Short-eared and Long-eared Owls on Migrating Songbirds Attracted to Artificial Lights Type Journal Article
Year 2012 Publication Journal of Raptor Research Abbreviated Journal Journal of Raptor Research
Volume 46 Issue 2 Pages 232-234
Keywords Asio otus; Long-eared Owl; birds; Asio flammeus; Short-eared Owl; artificial light; migration; predation
Abstract
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0892-1016 ISBN Medium
Area Expedition Conference
Notes Approved (down) no
Call Number IDA @ john @ Serial 61
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Author Woods, C.P.; Brigham, R.M.
Title Common Poorwill activity and calling behavior in relation to moonlight and predation Type Journal Article
Year 2008 Publication The Wilson Journal of Ornithology Abbreviated Journal The Wilson Journal of Ornithology
Volume 120 Issue 3 Pages 505-512
Keywords birds; poorwills; Common Poorwill; Phalaenoptilus nuttallii; Arizona; moonlight
Abstract We investigated the influence of lunar and environmental factors on behavior of Common Poorwills (Phalaenoptilus nuttallii) in southern Arizona under a diverse set of natural and artificial conditions. Radio-marked poorwills were most active shortly after sunset during the new moon. Movements declined as evening progressed. Activity remained high for several hours after sunset when the moon was full. Poorwills were heard calling from March through October, but most calling occurred between early May and September. Only ambient light was correlated with number of poorwills heard calling. More poorwills responded to playbacks of conspecifics when the moon was full than when it was new. Poorwills did not change their response to conspecifics during full moon when playback of poorwill calls followed playback of Great Horned Owl (Bubo virginianus) calls but, during the new moon, fewer birds responded following the owl call. Poorwill behavior is strongly influenced by lunar conditions; their ability to detect and evade predators is important when calling advertises their location.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1559-4491 ISBN Medium
Area Expedition Conference
Notes Approved (down) no
Call Number IDA @ john @ Serial 62
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