Data from: Effects of experimental night lighting on the daily timing of winter foraging in common European songbirds

Main Authors: Da Silva, Arnaud, Diez-Méndez, David, Kempenaers, Bart
Format: info dataset Journal
Terbitan: , 2017
Subjects:
Online Access: https://zenodo.org/record/4994902
Daftar Isi:
  • The ecological effects of light pollution are becoming better understood, especially in birds. Recent studies have shown that several bird species can use street lighting to extend activity into the night during the breeding season. However, most of these studies are correlational and little is known about the effects of artificial night lighting on the timing of activities outside the breeding season. During winter, low temperatures and short days may limit foraging opportunities and can negatively affect survival of resident birds. However, night lighting may allow them to expand the time niche available for foraging. Here, we report on a study where we repeatedly manipulated the amount of night lighting during early winter at automated feeding stations in a natural forest. We used video-recordings at the feeders to determine the time of the first (at dawn) and last (at dusk) foraging visits for six songbird species. We predicted that all species, and in particular the naturally early-foraging species, would advance their daily onset of foraging during the mornings with night lighting, but would show minimal or no delays in their daily cessation of foraging during the lighted evenings. We found that two early-foraging species, the blue tit and the great tit, started foraging earlier during the experimentally lighted mornings. However, in great tits, this effect was weak and restricted to nights with inclement weather. The light treatment did not have any effect on the start of foraging in the willow/marsh tit, the nuthatch, the European jay, and the blackbird. Artificial night lighting did not cause later foraging at dusk in any of the six species. Overall, our results suggest that artificial light during winter has only small effects on timing of foraging. We discuss these findings and the importance of temperature and winter weather in shaping the observed foraging patterns.
  • Relative times of onset and cessation of foragingData are shown for mornings ('Dawn' tab) and for evenings ('Dusk' tab) Site: experimental sites (N = 4). Numbers are used here and in the manuscript to designate the sites Treatment: whether the morning (at dawn) or evening (at dusk) was experimentally lighted ('light') or not ('dark') Date: day of the experimental morning (at dawn) and evening (at dusk), with 1 = 1 January. Missing days are due to experimental mishap (experimental schedule file available on demand). Temperature: daily air temperature at sunrise (at dawn) and sunset (at dusk) in degrees Celsius (obtained using light/temperature loggers, used to calculate the residuals of temperature against date in the models) Weather: whether the weather in the morning (at dawn) or evening (at dusk) was clement or adverse (snow and/or strong wind was observed) Extraction: experimenter that extracted the data (ADS = Arnaud Da Silva or DAD = David Diez-Méndez) Next columns: Tab 'Dawn': Daily Onset of foraging" (in min relative to sunrise) Tab 'Dusk' "Daily Cessation of foraging" (in min relative to sunset) for: Blackbird, Great_tit, Blue_tit, Poecile, Nuthatch, and Jay (only at dawn for the latter) For 'Dawn' Blackbird_outliers are data without the outliers after sunrise and Great_tit_outliers without 5 outliers >40 min before sunrise and 2 outliers >40 min after sunrise (for secondary analyses, see last paragraph of the methods)Foragingtimes.xls