DOI: 10.5061/dryad.51c59zw68
title: Weather effects on nestling survival of great tits vary according to the developmental stage

description: Organisms change breeding investments as a function of the environment,
 thereby maximizing reproductive success. Climate change studies of avian
 life-history have long focused on plasticity of laying dates and clutch
 sizes in response to weather conditions prior to clutch initiation. By
 contrast, effects of unpredictable weather events occurring after initial
 reproductive decisions are made have largely been ignored, despite
 becoming increasingly important with ongoing climate change. We studied
 the detrimental effects of fluctuations in temperature and precipitation
 during various nesting phases of great tits (Parus major), identifying the
 developmental age windows where weather fluctuations affected hatching,
 nestling mass and fledging success. We used a longitudinal (8-year)
 dataset of great tits breeding in next boxes in southern Germany and
 applied a recently introduced explorative approach that does not require a
 priori assumptions on the time windows (range of ages) over which weather
 may affect reproductive parameters. Lower temperatures and higher
 precipitation during the nestling phase negatively affected nestling mass
 and survival: nestlings between the ages 6-9 days were most susceptible to
 this form of variation in weather. Effects of weather did not differ
 between years, i.e., there was no evidence for ‘good’ versus ‘bad’ years.
 Future research should focus on the mechanisms underpinning effects of
 weather on nestling growth and survival in other populations and consider
 whether age-dependent weather consequences occur in a wide variety of
 taxa, as specific developmental stages may serve as weak spots in a
 scenario of increasing recurrence of weather extremes.
description: This dataset has two spreadsheets: Broods
 data: one brood per row. Includes spatiotemporal and nest content
 information.<br>
 Marques-Santos_Dingemanse_JAV_broods_dryad.csv Nestling
 data: one nestling per row. Includes nestling mass, spatiotemporal
 information, brood, and parental identification.<br>
 Marques-Santos_Dingemanse_JAV_nestlingmass_dryad.csv
 Data description: FirstEggDay<br> On
 which day of the year (starting April 1 as day 1) the first egg of the
 clutch was laid. LayingGap<br> The number of days
 during laying where no egg was laid.
 ClutchSize<br> The total number of eggs laid during the
 focal breeding attempt. Hatched<br> Whether the
 clutch has hatched at least one egg; 0 = no eggs hatched.
 HatchDay<br> On which day of the year (starting April 1 as
 day 1) the first egg of the clutch hatched.
 NumberHatched<br> The number of eggs that
 hatched. Plot<br> Plot identity. Nest box
 plot-specific unique identifier. BroodYear<br>
 Year identity. In which year the clutch was laid.
 MBirdID<br> Male bird identity. Individual-specific unique
 identifier. FBirdID<br> Female bird identity.
 Individual-specific unique identifier.
 Fledged<br> Whether the clutch has fledged. When at least
 half of the remaining young at age 14 has left the box. 0 = no chicks
 fledged. NumberFledged<br> The number of
 fledglings produced during the focal breeding attempt.
 BroodID<br> Brood identity. The brood-specific unique
 identifier associated with each nest attempt.
 Day14BodyMass<br> Nestling mass (g) at age 14
 days. NA<br> Missing values (applicable to
 multiple variables listed above).