DOI: 10.5061/dryad.641d25m
title: Data from: Nest height is affected by lamppost lighting proximity in addition to nestbox size in urban great tits

description: Both natural and artificial light have proximate influences on many
 aspects of avian biology, physiology and behaviour. To date artificial
 light at night is mostly considered as being a nuisance disrupting for
 instance sleep and reproduction of diurnal species. Here, we investigate
 if lamppost night lighting affects cavity-nesting bird species inside
 their breeding cavity. Nest height in secondary cavity-nesting species is
 the result of trade-offs between several selective forces. Predation is
 the prevailing force leading birds to build thin nests to increase the
 distance towards the entrance hole. A thin nest may also limit artificial
 light exposure at night. Yet, a minimum level of daylight inside nesting
 cavities is necessary for adequate visual communication and/or offspring
 development. Against this background, we hypothesised that avian
 nest-building behaviour varies in response to a change in night lighting.
 We monitored nest height of urban great tits (Parus major) during six
 years and found that it varied with artificial light proximity. The birds
 built thinner nests inside nestboxes of various sizes in response to
 increasing lamppost night light availability at the nest. In large
 nestboxes, the nests were also thinner when a lamppost was present in the
 territory. Whether this relationship between artificial night lighting and
 nest height reflects a positive or negative effect of urbanisation is
 discussed in the light of recent experimental studies conducted in rural
 populations by other research groups.
description: Characteristics of the
 nests, nestboxes, surrounding environment, laying females and their
 clutchesLEGEND - *Collected in
 the field. **Calculated electronically. ***Lamppost map created based on
 the Mapinfo data from the city of Montpellier
 (opendata.montpelliernumerique.fr/) with the Geographic Information System
 (QuantumGis 1.7.4), and then layered with the nestbox map to determine
 lamppost presence around nestboxes. ****Computed with Delta software
 providing maps and aerial pictures of the city of Montpellier. SITE AND
 NESTBOX CHARACTERISTICS – Site: five sites in Montpellier, France (1=Font
 Colombe, 2=Grammont, 3=Mas Nouguier, 4=Mosson, 5=Zoo du Lunaret).
 Boxidentity*: nestbox number giving their identity. BoxtypeClass and
 Boxtype*: 2=small wood-concrete Schwegler versus 3=medium larch-wood
 versus 4=large larch-wood nestboxes. Year: the 6 years of study (2011 to
 2016). BIOLOGICAL MEASUREMENTS AT NEST – Nestheight*: vertical height of
 the external nest wall (to the nearest 0.25 cm). Nestvolume**: nest volume
 calculated in multiplying nest height by the internal surface of the
 bottom of the nest chamber (cm3). Firsteggdate*: laying date of the first
 egg in a clutch (Julian date from January 1). Clutchsize*: clutch size
 from the second half of March onwards till mid-July. Stage: reproductive
 stage (nest measured 1=during the week before egg-laying versus 2=during
 egg-laying versus 3=after incubation onset). Clutchtype*: clutch type
 (1=first versus 2=second breeding attempts). FemaleRing*: female ring
 number giving the identity of the female parent. FemaleAge*: female age
 (1=yearling versus 2=older). FemaleMass*: female body mass to the nearest
 0.1 g. FemaleTarsus*: female tarsus length to the nearest 0.01 mm.
 ENVIRONMENTAL MEASUREMENTS AT NEST AND TERRITORY – LamppostPresence***:
 lamppost presence (1=at least one lamppost within a 100 m radius around
 each nestbox vs. 0=none). Distance*: distance (0-50 m) between the
 entrance hole of each nestbox and the closest lamppost bulb.
 VerticalAngle*: the vertical angle (-2-90°) between the entrance hole of
 each nestbox and the closest lamppost bulb. HorizontalAngle*: the
 horizontal angle (0-180°) between the entrance hole of each nestbox and
 the closest lamppost bulb. PermanentCover*: the light-blocking, permanent
 vegetation cover (in classes of 25% from 0 to 100%) between the entrance
 hole of each nestbox and the closest lamppost bulb.
 PC1LightAvailability**: night light availability at nest from the closest
 lamppost bulb as the first principal component PC1 (explaining 38.2% of
 the total variance, with distance to lamppost bulb=0.69, vertical
 angle=-0.58, horizontal angle= 0.59, light-blocking permanent vegetation
 cover=0.60) from the correlation matrix. Vegetation****: green spaces
 within a 50 m radius around each nestbox. Trees****: tree cover within a
 50 m radius around each nestbox. Oak*: oak cover within a 50 m radius
 around each nestbox. PC1Cover**: vegetation cover as the first principal
 component PC1 (explaining 81.9% of the total variance, with green spaces
 =0.90, tree cover =0.96, oak cover = 0.86) from the correlation
 matrix.Holveck et al JAB
 data.txt