scholarly journals Apparent Effects of Light Pollution on Singing Behavior of American Robins

The Condor ◽  
2006 ◽  
Vol 108 (1) ◽  
pp. 130-139 ◽  
Author(s):  
Mark W. Miller
Keyword(s):  
Bird Species ◽  
Population Level ◽  
Light Pollution ◽  
Artificial Light ◽  
Turdus Migratorius ◽  
Singing Behavior ◽  
Light Levels ◽  
American Robins ◽  
A Site ◽  
Avian Song

Abstract Astronomers consider light pollution to be a growing problem, however few studies have addressed potential effects of light pollution on wildlife. Sunlight is believed to initiate song in many bird species. If light initiates song, then light pollution may be influencing avian song behavior at a population level. This hypothesis predicts that birds breeding in areas with large amounts of artificial light will begin singing earlier in the day than birds in areas with little artificial light. Birds in highly illuminated areas might begin singing earlier than did birds in those same areas in previous years when artificial light levels were known to be, or were presumably, lower. Also, birds should begin singing earlier within a site on brightly lit nights. In 2002 and 2003 I documented initiation of morning song by breeding American Robins (Turdus migratorius) in areas with differing intensity of artificial nocturnal light. I compared my observations among sites and against historical studies. Robin populations in areas with large amounts of artificial light frequently began their morning chorus during true night. Chorus initiation time, relative to civil twilight, was positively correlated with amount of artificial light present during true night. Robin choruses in areas with little, or presumably little, artificial light have almost never begun during true night, instead appearing to track the onset of civil twilight. Proliferation of artificial nocturnal light may be strongly affecting singing behavior of American Robins at a population level.

scholarly journals Mimicry-dependent lateralization in the visual inspection of foreign eggs by American robins

2019 ◽  
Vol 15 (7) ◽  
pp. 20190351 ◽  
Author(s):  
Hannah M. Scharf ◽  
Katharine Stenstrom ◽  
Miri Dainson ◽  
Thomas J. Benson ◽  
Esteban Fernandez-Juricic ◽  
...  
Keyword(s):  
Visual Processing ◽  
Species Recognition ◽  
Molothrus Ater ◽  
Population Level ◽  
Brain Lateralization ◽  
Turdus Migratorius ◽  
Brain Hemispheres ◽  
Brood Parasites ◽  
Visual Hemifield ◽  
American Robins

Brain lateralization, or the specialization of function in the left versus right brain hemispheres, has been found in a variety of lineages in contexts ranging from foraging to social and sexual behaviours, including the recognition of conspecific social partners. Here we studied whether the recognition and rejection of avian brood parasitic eggs, another context for species recognition, may also involve lateralized visual processing. We focused on American robins ( Turdus migratorius ), an egg-rejecter host to occasional brood parasitism by brown-headed cowbirds ( Molothrus ater ) and tested if robins preferentially used one visual hemifield over the other to inspect mimetic versus non-mimetic model eggs. At the population level, robins showed a significantly lateralized absolute eyedness index (EI) when viewing mimetic model eggs, but individuals varied in left versus right visual hemifield preference. By contrast, absolute EI was significantly lower when viewing non-mimetic eggs. We also found that robins with more lateralized eye usage rejected model eggs at higher rates. We suggest that the inspection and recognition of foreign eggs represent a specialized and lateralized context of species recognition in this and perhaps in other egg-rejecter hosts of brood parasites.

scholarly journals Working with Inadequate Tools: Legislative Shortcomings in Protection against Ecological Effects of Artificial Light at Night

2020 ◽  
Vol 12 (6) ◽  
pp. 2551 ◽  
Author(s):  
Sibylle Schroer ◽  
Benedikt John Huggins ◽  
Clementine Azam ◽  
Franz Hölker
Keyword(s):  
Adverse Effects ◽  
Environmental Law ◽  
Population Level ◽  
Light Pollution ◽  
Artificial Light ◽  
Legal Analysis ◽  
Light At Night ◽  
Environmental Laws ◽  
Legal Obligations ◽  
Special Protection

The fundamental change in nocturnal landscapes due to the increasing use of artificial light at night (ALAN) is recognized as being detrimental to the environment and raises important regulatory questions as to whether and how it should be regulated based on the manifold risks to the environment. Here, we present the results of an analysis of the current legal obligations on ALAN in context with a systematic review of adverse effects. The legal analysis includes the relevant aspects of European and German environmental law, specifically nature conservation and immission control. The review represents the results of 303 studies indicating significant disturbances of organisms and landscapes. We discuss the conditions for prohibitions by environmental laws and whether protection gaps persist and, hence, whether specific legislation for light pollution is necessary. While protection is predominantly provided for species with special protection status that reveal avoidance behavior of artificially lit landscapes and associated habitat loss, adverse effects on species and landscapes without special protection status are often unaddressed by existing regulations. Legislative shortcomings are caused by difficulties in proving adverse effect on the population level, detecting lighting malpractice, and applying the law to ALAN-related situations. Measures to reduce ALAN-induced environmental impacts are highlighted. We discuss whether an obligation to implement such measures is favorable for environmental protection and how regulations can be implemented.

scholarly journals Assessing coastal artificial light and potential exposure of wildlife at a national scale: the case of marine turtles in Brazil

2020 ◽  
Vol 29 (4) ◽  
pp. 1135-1152 ◽  
Author(s):  
Liliana P. Colman ◽  
Paulo H. Lara ◽  
Jonathan Bennie ◽  
Annette C. Broderick ◽  
Juliana R. de Freitas ◽  
...  
Keyword(s):  
Nest Site Selection ◽  
Marine Turtle ◽  
Conservation Strategies ◽  
Brazilian Coast ◽  
Light Pollution ◽  
Artificial Light ◽  
Turtle Species ◽  
Marine Turtles ◽  
Light Levels ◽  
Nesting Beaches

AbstractCoastal areas provide critical nesting habitat for marine turtles. Understanding how artificial light might impact populations is key to guide management strategies. Here we assess the extent to which nesting populations of four marine turtle species—leatherback (Dermochelys coriacea), olive ridley (Lepidochelys olivacea), hawksbill (Eretmochelys imbricata) and two subpopulations of loggerhead (Caretta caretta) turtles—are exposed to light pollution across 604 km of the Brazilian coast. We used yearly night-time satellite images from two 5-year periods (1992–1996 and 2008–2012) from the US Air Force Defense Meteorological Satellite Programme (DMSP) to determine the proportion of nesting areas that are exposed to detectable levels of artificial light and identify how this has changed over time. Over the monitored time-frame, 63.7% of the nesting beaches experienced an increase in night light levels. Based on nest densities, we identified 54 reproductive hotspots: 62.9% were located in areas potentially exposed to light pollution. Light levels appeared to have a significant effect on nest densities of hawksbills and the northern loggerhead turtle stock, however high nest densities were also seen in lit areas. The status of all species/subpopulations has improved across the time period despite increased light levels. These findings suggest that (1) nest site selection is likely primarily determined by variables other than light and (2) conservation strategies in Brazil appear to have been successful in contributing to reducing impacts on nesting beaches. There is, however, the possibility that light also affects hatchlings in coastal waters, and impacts on population recruitment may take longer to fully manifest in nesting numbers. Recommendations are made to further this work to provide deeper insights into the impacts of anthropogenic light on marine turtles.

scholarly journals Bloodmeal, Host Selection, and Genetic Admixture Analyses of Culex pipiens Complex (Diptera: Culicidae) Mosquitoes in Chicago, IL

2019 ◽  
Vol 57 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Linda Kothera ◽  
John-Paul Mutebi ◽  
Joan L Kenney ◽  
Kali Saxton-Shaw ◽  
Michael P Ward ◽  
...  
Keyword(s):  
Culex Pipiens ◽  
Bird Species ◽  
Passer Domesticus ◽  
Genetic Admixture ◽  
Turdus Migratorius ◽  
Public Park ◽  
Point Count ◽  
Culex Pipiens Complex ◽  
American Robins ◽  
Almost All

Abstract The area in and around Chicago, IL, is a hotspot of West Nile virus activity. The discovery of a Culex pipiens form molestus Forskӓl population in Chicago in 2009 added to speculation that offspring from hybridization between Cx. pipiens f. pipiens L. and f. molestus could show a preference for feeding on humans. We collected blood-fed female mosquitoes (N = 1,023) from eight residential sites and one public park site in Chicago in July and August 2012. Bloodmeal analysis using the COI (cytochrome c oxidase subunit I) gene was performed to ascertain host choice. Almost all (99%) bloodmeals came from birds, with American Robins (Turdus migratorius L.) and House Sparrows (Passer domesticus L.) making up the largest percentage (74% combined). A forage ratio analysis comparing bird species fed upon and available bird species based on point count surveys indicated Northern Cardinals (Cardinalis cardinalis) and American Robins (Turdus migratorius) appeared to be over-utilized, whereas several species were under-utilized. Two human bloodmeals came from Culex pipiens complex mosquitoes. Admixture and population genetic analyses were conducted with 15 microsatellite loci on head and thorax DNA from the collected blood-fed mosquitoes. A modest amount of hybridization was detected between Cx. pipiens f. pipiens and f. molestus, as well as between f. pipiens and Cx. quinquefasciatus Say. Several pure Cx. quinquefasciatus individuals were noted at the two Trumbull Park sites. Our data suggest that Cx. pipiens complex mosquitoes in the Chicago area are not highly introgressed with f. molestus and appear to utilize avian hosts.

scholarly journals Anthropogenic noise, but not artificial light levels predicts song behaviour in an equatorial bird

2016 ◽  
Vol 3 (7) ◽  
pp. 160231 ◽  
Author(s):  
Adriana M. Dorado-Correa ◽  
Manuel Rodríguez-Rocha ◽  
Henrik Brumm
Keyword(s):  
Rural Areas ◽  
Traffic Noise ◽  
Day Length ◽  
Light Pollution ◽  
Artificial Light ◽  
Noise Levels ◽  
Tropical Birds ◽  
Light Levels ◽  
Zonotrichia Capensis ◽  
Singing Activity

Birds in cities start singing earlier in the morning than in rural areas; commonly this shift is attributed to light pollution. Some studies have suggested that traffic noise has a stronger influence on singing activity than artificial light does. Changes in the timing of singing behaviour in relation to noise and light pollution have only been investigated in the temperate zones. Tropical birds, however, experience little seasonal variation in day length and may be less dependent on light intensity as a modifier for reproductive behaviours such as song. To test whether noise or light pollution has a stronger impact on the dawn chorus of a tropical bird, we investigated the singing behaviour of rufous-collared sparrows ( Zonotrichia capensis ) in Bogota, Colombia at two times during the year. We found that birds in places with high noise levels started to sing earlier. Light pollution did not have a significant effect. Birds may begin to sing earlier in noisy areas to avoid acoustic masking by traffic later in the morning. Our results also suggest that some tropical birds may be less sensitive to variations in day length and thus less sensitive to light pollution.

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