DOI: 10.5061/dryad.2bvq83c1k
title: Data from: Climate change and nest predation affect shifts in timing and duration of breeding as well as reproductive success in a migratory species

description: While it is well known that the overall timing of avian breeding in
 northern latitudes has generally advanced due to climate change, it is
 still unclear how climate warming has affected the beginning, end, and
 duration of the breeding period and reproductive success of birds. This is
 because changes in the phenological breeding metrics have often been
 studied using ringing data that are based on successful nests only and
 impacts of local factors such as nest predation have not been analysed
 simultaneously. This study used both successful and failed nesting
 attempts to estimate the annual timing and duration of breeding in common
 goldeneyes (Bucephala clangula). There was strong evidence that the
 beginning of breeding has advanced during 1995‒2022 but only weak evidence
 that the end of breeding has advanced. Consequently, the duration of the
 breeding period lengthened, although statistical evidence for the trend
 was only weak. The relative importance of climate change and nest
 predation in affecting the timing and duration of breeding as well as
 breeding success was also studied. Among-year variation in the beginning
 of breeding was mainly governed by the timing of ice breakup, an indicator
 of climate change, whereas nest predation rate in the previous year was
 the main driver of the end of breeding, the duration of breeding being
 affected by both the timing of ice breakup and nest predation rate. Annual
 nest-stage success was best explained by nest predation rate. However,
 final reproductive success (proportion of nest-left ducklings that
 survived until independence) decreased with advancing timing of ice
 breakup, suggesting that climate change has negatively affected the
 production of independent offspring in the study population. The findings
 of this study underline the importance of considering also local
 ecological factors when analysing climate change impacts on phenological
 breeding metrics and breeding success of birds.
description: I used long-term (1995-2022) population level data of both
 successful and failed nesting attempts and studied shifts in the timing
 and duration of breeding, and associated changes in breeding success, of
 the common goldeneye (<em>Bucephala clangula</em>) in relation
 to climate change-induced shifts in spring phenology (measured in terms of
 the timing of ice breakup in the breeding lakes) and among-year variation
 in nest predation rate.
description: # **Data from: Climate change and nest predation affect shifts in timing
 and duration of breeding as well as reproductive success in a migratory
 species** This dataset consists of a Data_from_Poysa_JAV-03373 Excel file.
 The data include annual (1995-2022) values for the following variables (NA
 means no data for these years and variables). YEAR START, start of
 breeding = the 5th percentile of the annual start-of-laying distribution
 (scale: …, -1 = 29 April, 0 = 30 April, 1 = 1 May,….) END, end of breeding
 = the 95th percentile of the annual start-of-laying distribution (scale:
 …, -1 = 29 April, 0 = 30 April, 1 = 1 May,…) DURATION, duration of
 breeding = the difference between START and END IOD, ice-out date = timing
 of ice breakup (scale: 1 = 1 April, 2 = 2 April, 3 = 3 April, ...)
 PREDATIONT = nest predation rate (%) in year t PREDATIONT-1 = nest
 predation rate (%) in year t-1 (note that data from year 1994 also
 included) NESTSUCCESS, nest success = the proportion eggs that produced an
 offspring that left the nest FINALSUCCESS-INCL, final reproductive success
 = the proportion of nest-left ducklings that survived to independence,
 data from a beaver-flooded lake included FINALSUCCESS-EXCL, final
 reproductive success = the proportion of nest-left ducklings that survived
 to independence, data from a beaver flooded lake excluded