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Author Longcore, T.; Rich, C.; Mineau, P.; MacDonald, B.; Bert, D.G.; Sullivan, L.M.; Mutrie, E.; Gauthreaux, S.A.J.; Avery, M.L.; Crawford, R.L.; Manville, A.M. 2nd; Travis, E.R.; Drake, D.
Title An estimate of avian mortality at communication towers in the United States and Canada Type Journal Article
Year 2012 Publication PloS one Abbreviated Journal PLoS One
Volume 7 Issue 4 Pages e34025
Keywords Ecology; Accidents/*statistics & numerical data; Altitude; Animals; Birds/*injuries; Canada; Computer Communication Networks/*instrumentation; Conservation of Natural Resources/*statistics & numerical data; *Flight, Animal; *Mortality; Regression Analysis; United States
Abstract Avian mortality at communication towers in the continental United States and Canada is an issue of pressing conservation concern. Previous estimates of this mortality have been based on limited data and have not included Canada. We compiled a database of communication towers in the continental United States and Canada and estimated avian mortality by tower with a regression relating avian mortality to tower height. This equation was derived from 38 tower studies for which mortality data were available and corrected for sampling effort, search efficiency, and scavenging where appropriate. Although most studies document mortality at guyed towers with steady-burning lights, we accounted for lower mortality at towers without guy wires or steady-burning lights by adjusting estimates based on published studies. The resulting estimate of mortality at towers is 6.8 million birds per year in the United States and Canada. Bootstrapped subsampling indicated that the regression was robust to the choice of studies included and a comparison of multiple regression models showed that incorporating sampling, scavenging, and search efficiency adjustments improved model fit. Estimating total avian mortality is only a first step in developing an assessment of the biological significance of mortality at communication towers for individual species or groups of species. Nevertheless, our estimate can be used to evaluate this source of mortality, develop subsequent per-species mortality estimates, and motivate policy action.
Address (up) The Urban Wildlands Group, Los Angeles, California, United States of America. longcore@urbanwildlands.org
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 1932-6203 ISBN Medium
Area Expedition Conference
Notes PMID:22558082; PMCID:PMC3338802 Approved no
Call Number LoNNe @ christopher.kyba @ Serial 475
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Author Duriscoe, D.M.
Title Photometric indicators of visual night sky quality derived from all-sky brightness maps Type Journal Article
Year 2016 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal JQSRT
Volume 181 Issue Pages 33-45
Keywords Skyglow; Instrumentation
Abstract Wide angle or fisheye cameras provide a high resolution record of artificial sky glow, which results from the scattering of escaped anthropogenic light by the atmosphere, over the sky vault in the moonless nocturnal environment. Analysis of this record yields important indicators of the extent and severity of light pollution. The following indicators were derived through numerical analysis of all-sky brightness maps: zenithal, average all-sky, median, brightest, and darkest sky brightness. In addition, horizontal and vertical illuminance, resulting from sky brightness were computed. A natural reference condition to which the anthropogenic component may be compared is proposed for each indicator, based upon an iterative analysis of a high resolution natural sky model. All-sky brightness data, calibrated in the V band by photometry of standard stars and converted to luminance, from 406 separate data sets were included in an exploratory analysis. Of these, six locations representing a wide range of severity of impact from artificial sky brightness were selected as examples and examined in detail. All-sky average brightness is the most unbiased indicator of impact to the environment, and is more sensitive and accurate in areas of slight to moderate light pollution impact than zenith brightness. Maximum vertical illuminance provides an excellent indicator of impacts to wilderness character, as does measures of the brightest portions of the sky. Zenith brightness, the workhorse of field campaigns, is compared to the other indicators and found to correlate well with horizontal illuminance, especially at relatively bright sites. The median sky brightness describes a brightness threshold for the upper half of the sky, of importance to telescopic optical astronomy. Numeric indicators, in concert with all-sky brightness maps, provide a complete assessment of visual sky quality at a site.
Address (up) U.S. National Park Service, Natural Sounds and Night Skies Division, 351 Pacu Lane, Bishop, CA 93514, USA; dan_duriscoe(at)nps.gov
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4073 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ ; IDA @ john @ Serial 1376
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