DOI: 10.5061/dryad.n026d
title: Data from: Hidden survival heterogeneity of three common eider populations in response to climate fluctuations

description: (1) Understanding how individuals and populations respond to fluctuations
 in climatic conditions is critical to explain and anticipate changes in
 ecological systems. Most such studies focus on climate impacts on single
 populations without considering inter- and intra-population heterogeneity.
 However, comparing geographically dispersed populations limits the risk of
 faulty generalizations and helps to improve ecological and demographic
 models. (2) We aimed to determine whether differences in migration tactics
 among and within populations would induce inter- or intra-population
 heterogeneity in survival in relation to winter climate fluctuations. Our
 study species was the Common eider (Somateria mollissima), a marine duck
 with a circumpolar distribution, which is strongly affected by climatic
 conditions during several phases of its annual cycle. (3)
 Capture-mark-recapture (CMR) data were collected in two arctic (northern
 Canada and Svalbard) and one subarctic (northern Norway) population over a
 period of 18, 15 and 29 years, respectively. These three populations have
 different migration tactics and experience different winter climatic
 conditions. Using multi-event and mixture modelling, we assessed the
 association between adult female eider survival and winter conditions as
 measured by the North Atlantic Oscillation index. (4) We found that winter
 weather conditions affected survival of female eiders from each of these
 three populations. However, different mechanisms seemed to be involved.
 Survival of the two migrating arctic populations was impacted directly by
 changes in the NAO, whereas the subarctic resident population was affected
 by the NAO with time lags of two to three years. Moreover, we found
 evidence for intra-population heterogeneity in the survival response to
 the winter NAO in the Canadian eider population, where individuals migrate
 to distinct wintering areas. (5) Our results illustrate how individuals
 and populations of the same species can vary in their responses to climate
 variation. We suspect that the found variation in survival response of
 birds to winter conditions is partly explained by differences in migration
 tactic. Detecting and accounting for inter- and intra-population
 heterogeneity will improve our predictions concerning the response of
 wildlife to global changes.
description: Dataset_EastBay_CanadaData were collected annually in the East Bay Migratory Bird Sanctuary, Canada from 1996 to 2013. This txt file is the headed format directly usable in E-surge program (see E-surge manual and Appendix S2). Each line represents an individual capture history with 1 when it has been seen and 0 with it has not been seen. The 18 first columns are each year (e.g. A1996 for year 1996). The "S" column is the sample size (i.e. associated number of individuals) and the "RC" column is the right censoring column.Data_PrinsHeinrich_SvalbardData were collected annually on Prins Heinrich Island on the west coast of Svalbard from 1999 to 2013. This txt file is the headed format directly usable in E-surge program (see E-surge manual and Appendix S2). Each line represents an individual capture history with 1 when it has been seen and 0 with it has not been seen. The 15 first columns are each year (e.g. A1999 for year 1999). The "S" column is the sample size (i.e. associated number of individuals).Data_Grindoya_NorwayData were collected annually on Grindøya near Tromsø, northern Norway from 1985 to 2013. This txt file is the headed format directly usable in E-surge program (see E-surge manual and Appendix S2). Each line represents an individual capture history with 1 when it has been seen and 0 with it has not been seen. The 29 first columns are each year (e.g. A1996 for year 1996). The "S" column is the sample size (i.e. associated number of individuals) and the "RC" column is the right censoring column.