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Pun, C. S. J., & So, C. W. (2012). Night-sky brightness monitoring in Hong Kong: a city-wide light pollution assessment. Environ Monit Assess, 184(4), 2537–2557.
Abstract: Results of the first comprehensive light pollution survey in Hong Kong are presented. The night-sky brightness was measured and monitored around the city using a portable light-sensing device called the Sky Quality Meter over a 15-month period beginning in March 2008. A total of 1,957 data sets were taken at 199 distinct locations, including urban and rural sites covering all 18 Administrative Districts of Hong Kong. The survey shows that the environmental light pollution problem in Hong Kong is severe-the urban night skies (sky brightness at 15.0 mag arcsec(- 2)) are on average ~ 100 times brighter than at the darkest rural sites (20.1 mag arcsec(- 2)), indicating that the high lighting densities in the densely populated residential and commercial areas lead to light pollution. In the worst polluted urban location studied, the night-sky at 13.2 mag arcsec(- 2) can be over 500 times brighter than the darkest sites in Hong Kong. The observed night-sky brightness is found to be affected by human factors such as land utilization and population density of the observation sites, together with meteorological and/or environmental factors. Moreover, earlier night skies (at 9:30 p.m. local time) are generally brighter than later time (at 11:30 p.m.), which can be attributed to some public and commercial lightings being turned off later at night. On the other hand, no concrete relationship between the observed sky brightness and air pollutant concentrations could be established with the limited survey sampling. Results from this survey will serve as an important database for the public to assess whether new rules and regulations are necessary to control the use of outdoor lightings in Hong Kong.
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Schirmer, A. E., Gallemore, C., Liu, T., Magle, S., DiNello, E., Ahmed, H., et al. (2019). Mapping behaviorally relevant light pollution levels to improve urban habitat planning. Sci Rep, 9(1), 1–13.
Abstract: Artificial nighttime lights have important behavioral and ecological effects on wildlife. Combining laboratory and field techniques, we identified behaviorally relevant levels of nighttime light and mapped the extent of these light levels across the city of Chicago. We began by applying a Gaussian finite mixture model to 998 sampled illumination levels around Chicago to identify clusters of light levels. A simplified sample of these levels was replicated in the laboratory to identify light levels at which C57BL/6J mice exhibited altered circadian activity patterns. We then used camera trap and high-altitude photographic data to compare our field and laboratory observations, finding activity pattern changes in the field consistent with laboratory observations. Using these results, we mapped areas across Chicago exposed to estimated illumination levels above the value associated with statistically significant behavioral changes. Based on this measure, we found that as much as 36% of the greenspace in the city is in areas illuminated at levels greater than or equal to those at which we observe behavioral differences in the field and in the laboratory. Our findings provide evidence that artificial lighting patterns may influence wildlife behavior at a broad scale throughout urban areas, and should be considered in urban habitat planning.
Keywords: Animals; Remote Sensing; Society; remote sensing; cities; Urban planning; urban wildlife; urban ecology
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Stone, E. L., Jones, G., & Harris, S. (2009). Street lighting disturbs commuting bats. Curr Biol, 19(13), 1123–1127.
Abstract: Anthropogenic disturbance is a major cause of worldwide declines in biodiversity. Understanding the implications of this disturbance for species and populations is crucial for conservation biologists wishing to mitigate negative effects. Anthropogenic light pollution is an increasing global problem, affecting ecological interactions across a range of taxa and impacting negatively upon critical animal behaviors including foraging, reproduction, and communication (for review see). Almost all bats are nocturnal, making them ideal subjects for testing the effects of light pollution. Previous studies have shown that bat species adapted to foraging in open environments feed on insects attracted to mercury vapor lamps. Here, we use an experimental approach to provide the first evidence of a negative effect of artificial light pollution on the commuting behavior of a threatened bat species. We installed high-pressure sodium lights that mimic the intensity and light spectra of streetlights along commuting routes of lesser horseshoe bats (Rhinolophus hipposideros). Bat activity was reduced dramatically and the onset of commuting behavior was delayed in the presence of lighting, with no evidence of habituation. These results demonstrate that light pollution may have significant negative impacts upon the selection of flight routes by bats.
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