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Author Jetz, W.; Steffen, J.; Linsenmair, K.E. url  doi
openurl 
  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 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.  
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  Series Volume Series Issue Edition  
  ISSN 0030-1299 ISBN Medium  
  Area (down) Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 48  
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Author Dominoni, D.M.; Quetting, M.; Partecke, J. url  doi
openurl 
  Title Long-term effects of chronic light pollution on seasonal functions of European blackbirds (Turdus merula) Type Journal Article
  Year 2013 Publication PloS one Abbreviated Journal PLoS One  
  Volume 8 Issue 12 Pages e85069  
  Keywords Turdus merula; European blackbird; birds; animals; Reproduction  
  Abstract Light pollution is known to affect important biological functions of wild animals, including daily and annual cycles. However, knowledge about long-term effects of chronic exposure to artificial light at night is still very limited. Here we present data on reproductive physiology, molt and locomotor activity during two-year cycles of European blackbirds (Turdus merula) exposed to either dark nights or 0.3 lux at night. As expected, control birds kept under dark nights exhibited two regular testicular and testosterone cycles during the two-year experiment. Control urban birds developed testes faster than their control rural conspecifics. Conversely, while in the first year blackbirds exposed to light at night showed a normal but earlier gonadal cycle compared to control birds, during the second year the reproductive system did not develop at all: both testicular size and testosterone concentration were at baseline levels in all birds. In addition, molt sequence in light-treated birds was more irregular than in control birds in both years. Analysis of locomotor activity showed that birds were still synchronized to the underlying light-dark cycle. We suggest that the lack of reproductive activity and irregular molt progression were possibly the results of i) birds being stuck in a photorefractory state and/or ii) chronic stress. Our data show that chronic low intensities of light at night can dramatically affect the reproductive system. Future studies are needed in order to investigate if and how urban animals avoid such negative impact and to elucidate the physiological mechanisms behind these profound long-term effects of artificial light at night. Finally we call for collaboration between scientists and policy makers to limit the impact of light pollution on animals and ecosystems.  
  Address Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, Radolfzell, Germany ; Department of Biology, University of Konstanz, Konstanz, Germany  
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  Language English Summary Language Original Title  
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  ISSN 1932-6203 ISBN Medium  
  Area (down) Expedition Conference  
  Notes PMID:24376865; PMCID:PMC3869906 Approved no  
  Call Number IDA @ john @ Serial 49  
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Author Dominoni, D.; Quetting, M.; Partecke, J. url  doi
openurl 
  Title Artificial light at night advances avian reproductive physiology Type Journal Article
  Year 2013 Publication Proceedings. Biological Sciences / The Royal Society Abbreviated Journal Proc Biol Sci  
  Volume 280 Issue 1756 Pages 20123017  
  Keywords Animals; *Lighting; Male; Molting; Photoperiod; Reproduction/*physiology; Singing; Songbirds/*physiology; Testis/anatomy & histology; Testosterone/blood; Trees  
  Abstract Artificial light at night is a rapidly increasing phenomenon and it is presumed to have global implications. Light at night has been associated with health problems in humans as a consequence of altered biological rhythms. Effects on wild animals have been less investigated, but light at night has often been assumed to affect seasonal cycles of urban dwellers. Using light loggers attached to free-living European blackbirds (Turdus merula), we first measured light intensity at night which forest and city birds are subjected to in the wild. Then we used these measurements to test for the effect of light at night on timing of reproductive physiology. Captive city and forest blackbirds were exposed to either dark nights or very low light intensities at night (0.3 lux). Birds exposed to light at night developed their reproductive system up to one month earlier, and also moulted earlier, than birds kept under dark nights. Furthermore, city birds responded differently than forest individuals to the light at night treatment, suggesting that urbanization can alter the physiological phenotype of songbirds. Our results emphasize the impact of human-induced lighting on the ecology of millions of animals living in cities and call for an understanding of the fitness consequences of light pollution.  
  Address Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, Radolfzell 78315, Germany. ddominoni@orn.mpg.de  
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  Series Volume Series Issue Edition  
  ISSN 0962-8452 ISBN Medium  
  Area (down) Expedition Conference  
  Notes PMID:23407836; PMCID:PMC3574380 Approved no  
  Call Number IDA @ john @ Serial 50  
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Author Kempenaers, B.; Borgstrom, P.; Loes, P.; Schlicht, E.; Valcu, M. url  doi
openurl 
  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  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0960-9822 ISBN Medium  
  Area (down) Expedition Conference  
  Notes PMID:20850324 Approved no  
  Call Number IDA @ john @ Serial 51  
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Author Baker, G.C.; Dekker, R.W.R.J. url  doi
openurl 
  Title Lunar synchrony in the reproduction of the Moluccan Megapode Megapodius wallacei Type Journal Article
  Year 2000 Publication Ibis Abbreviated Journal  
  Volume 142 Issue 3 Pages 382-388  
  Keywords Moluccan Megapode; Megapodius wallacei; birds; nesting; reproduction; animals; *Moon  
  Abstract The Moluccan Megapode Megapodius wallacei uses heat generated by the sun to incubate its eggs. It buries the eggs deep in the sand of sun-exposed beaches and open sandy areas on islands in the Moluccas, Indonesia. The eggs are laid at night and left to incubate for two to three months without parental care. We present evidence that the Moluccan Megapode exhibits lunar synchrony in the timing of egg-laying, its spatial distribution of egg burrows and in its behaviour at communal nesting grounds. More Moluccan Megapodes visit the nesting grounds on bright nights than during the new moon. Data collected on the spatial distribution and depth of egg burrows also exhibit lunar periodicity. On moonlit nights, the birds excavate burrows in communal groups and spend longer at the nesting ground digging deeper burrows. Lunaphilia and lunar periodicity of reproduction are rarely documented in birds. We discuss possible explanations for these behaviours in the Moluccan Megapode.  
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  Series Volume Series Issue Edition  
  ISSN 0019-1019 ISBN Medium  
  Area (down) Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 52  
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