Remote sensing to map influence of light pollution on Cory’s shearwater in São Miguel Island, Azores Archipelago

Abstract

Global economic and population growth increase the extent and intensity of artificial night lighting. From an ecological perspective, this is light pollution, which causes changes in reproductive physiology, migration and foraging of many species and ultimately leads to loss of biodiversity. Some seabirds are intimately linked with the light features of their environments because they are nocturnally active. We report light-induced groundings of Cory's shearwater (Calonectris diomedea) during a 2-year study (2008 and 2009) in São Miguel Island, in the Azores archipelago, and investigate the spatial correlation of locations of grounded birds with an annual composite of remotely sensed stable lights. Results indicate that 16.7% of fledglings are attracted to lights. The exposure of shearwater colonies in the study area to artificial night lighting is low overall. Four colonies account for 87% of the grounded birds. The distance each bird was found from the closest colony was best explained by the ratio of the satellite-measured light levels at the grounding spot to the light levels at the assigned colony of origin. These results demonstrate that satellite-observed nighttime lights are sufficient to assess risk to marine birds at the scale of oceanic islands and indicate their utility for monitoring the effectiveness of programs to manage lighting to reduce risk for these species and conducting global assessments of species vulnerability. To minimize the impact on Cory's shearwater and other marine birds, we recommend measures such as reduction and control of lighting intensity near colony locations, while continuing and re-enforcing rescue campaigns.

Using observed seabird fallout records to infer patterns of attraction to artificial light

“…The findings of our study support and build upon those of a recent study, in which light intensity was positively correlated with the number of downed fledgling shearwaters (Rodrigues et al 2012). Expected numbers from the light intensity model were based only on the mean intensity of light within fallout sectors; however, given known information related to mechanics of light attraction and the biology of the species, this model carries assumptions of bird movement that were not previously discussed.…”

“…Troy et al 2011), as well as the relationship between light and seabird fallout (e.g. Rodrigues et al 2012, Rodriguez et al 2012b), on a large scale. Even if one considers the extreme assumption that all light sources on the island emit a light intensity equal to 63 relative units (the highest pixel value for the planet), meaning that differences in pixel values were only due to the number of lights within the pixel area, it is highly likely that pixelsized areas with more light sources can attract more fledglings than areas with fewer lights.…”

“…More than 30 000 Newell's shearwater fledglings have been found as victims of fallout on Kauai during the past few decades (Griesemer & Holmes 2011), and thousands of other young shearwaters, petrels, and storm-petrels from different islands around the world are downed as a result of light annually (e.g. Le Corre et al 2002, Miles et al 2010, Fontaine et al 2011, Rodrigues et al 2012, Rodriguez et al 2012b. Despite this large number of fallout observations, certain elements of this phenomenon remain unknown, including the locations along the path from nest to the ocean from which fledglings are consistently drawn off course and downed by artificial light (i.e.…”

Coastal light pollution and marine turtles: assessing the magnitude of the problem

“…The data collected by the DMSP sensors corresponded to an area greater than that of actual light sources on the ground (Rodrigues et al 2012) due to the phenomenon of 'skyglow', which refers to the dome of light projected upwards and outwards from urban areas at night (Chalkias et al 2006). Skyglow is considered to contribute significantly to ecological impacts from light pollution (Rich & Longcore 2006, Kyba et al 2011.…”

Evaluating Multi-Sensor Nighttime Earth Observation Data for Identification of Mixed vs. Residential Use in Urban Areas

“…Cuenca City is located in the mountainous southern region of Ecuador at an elevation of around 2500 m above sea level and is the capital of the Azuay province ( The use of satellite-observed nighttime lights has a long tradition in research dealing with monitoring urban areas and patterns of human and economic activity [10][11][12][13][14][15][16] as well as its impact on the environment [17][18][19]. As opposed to attempts of using nighttime lights for basic delineation of urban areas or as weights for population disaggregation, in this paper we rather aim at exploring the use and value in determining intra-urban characteristics.…”