As migratory birds travel back and forth between their breeding and wintering grounds twice each year, they face many hazards. For species that migrate during the night, one of those dangers is the disorienting influence of light pollution from cities. A new study in the journal Environmental Pollution examines how artificial light at night and urban landcover are associated with the presence of nocturnal migrants across seasons.
Scientists from the Cornell Lab of Ornithology and Colorado State University used observations from the Lab’s eBird citizen-science program to estimate the seasonal species richness of nocturnally migrating passerines within 333 well surveyed urban areas in the contiguous U.S. “Richness” is defined as the number of different species in an area.
“We modelled the relationship between species richness and the level of light pollution, the proportion of tree canopy cover, and the proportion of impervious surface, such as roads and parking lots, across urban areas” says lead author Frank La Sorte at the Cornell Lab. MORE
Header image: Seasonal species richness of nocturnally migrating passerine bird species within 333 urban areas located in the contiguous USA. Credit: Frank La Sorte, Cornell Lab of Ornithology.