Anthropogenic Illumination as Guiding Light for Nocturnal Bird Migrants Identified by Remote Sensing

Nadja Weisshaupt, Matti Leskinen, Dmitri Moisseev, Jarmo Koistinen

Research output: Contribution to journalArticleScientificpeer-review


Migrant birds rely on environmental and celestial cues for navigation and orientation during their journeys. Adverse weather, such as heavy rain or fog, but also thick layers of low-level clouds, affect visibility and can challenge birds' ability to orientate. Therefore, birds typically favour certain meteorological conditions for migration. Photopollution from artificial lights outdoors and radiated from buildings is known to negatively affect nocturnal migrants' flight behaviour and trajectories, which may lead to collisions with human infrastructure. Positive effects of artificial light have been identified in some stationary birds, e.g., for extended foraging hours, though not during migration. In the present study, we show the effect of artificial light on the concentration and flight directions of migrating birds during overcast conditions in the peri-urban woodland in Southern Finland. Overcast conditions, by low-level clouds, prompted birds to migrate at low altitudes. Instead of spatially homogenous large-scale migration patterns, birds were observed to adapt their flight directions, in accordance with the artificial lights of the urbanized area. By using dual- and single-polarisation weather radar data we were able to study small-scale patterns of bird movements under the influence of low-level cloud layers. These cases show the remarkable capability of the existing weather radar networks to study bird migration.
Original languageEnglish
Article number1616
JournalRemote Sensing
Issue number7
Number of pages13
Publication statusPublished - Apr 2022
MoE publication typeA1 Journal article-refereed

Fields of Science

  • Aeroecology
  • Doppler velocity
  • Dual-polarisation radar
  • Passerine migration
  • Photopollution
  • Remote sensing
  • 114 Physical sciences
  • 1171 Geosciences

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