DOI: 10.5061/dryad.b107q48
title: Data from: Differences in seasonal survival suggest species-specific reactions to climate change in two sympatric bat species

description: Long-lived animals with a low annual reproductive output need a long time
 to recover from population crashes and are, thus, likely to face high
 extinction risk, if the current global environmental change will increase
 mortality rates. To aid conservation of those species, knowledge on the
 variability of mortality rates is essential. Unfortunately, however,
 individual-based multi-year data sets that are required for that have only
 rarely been collected for free-ranging long-lived mammals. Here, we used a
 five-year data set comprising activity data of 1445 RFID-tagged
 individuals of two long-lived temperate zone bat species, Natterer’s bats
 (Myotis nattereri) and Daubenton’s bats (Myotis daubentonii), at their
 joint hibernaculum. Both species are listed as being of high conservation
 interest by the European Habitats Directive. Applying mixed-effects
 logistic regression, we explored seasonal survival differences in these
 two species which differ in foraging strategy and phenology. In both
 species, survival over the first-winter of an individual’s life was much
 lower than survival over subsequent winters. Focussing on adults only,
 seasonal survival patterns were largely consistent with higher winter and
 lower summer survival but varied in its level across years in both
 species. Our analyses, furthermore, highlight the importance of
 species-specific time periods for survival. Daubenton’s bats showed a much
 stronger difference in survival between the two seasons than Natterer’s
 bats. In one exceptional winter, the population of Natterer’s bats
 crashed, while the survival of Daubenton’s bats declined only moderately.
 While, our results confirm the general seasonal survival pattern typical
 for hibernating mammals with higher winter than summer survival, they also
 show that this pattern can be reversed under particular conditions.
 Overall, our study points towards a high importance of specific time
 periods for population dynamics and suggests species-, population- and age
 class-specific responses to global climate change.
description: SeasonalSurvivalBats_DataSetThe file contains data on seasonal survival in bats collected at a hibernaculum in the field. The csv file has been created with the software R. It shows information about the according hibernation period (batyear; August - April of the five study years 2010/2011 - 2014/2015); the specific part of the hibernation period in detail (time_period), the season (season; winter, summer), the bat species (species; mn - Myotis nattereri, md - Myotis daubentonii), individual bats (bat_id), the sex of the individual (sex; f - female, m - male), the assigned age class of the individual (age_class; ad - adult, juv - juvenile), the presence within the specific time period (presence; 1 - has been present, 0 - has not been recorded at the hibernaculum although it has been alive) and status of survival (surv; 1 - survived, 0 - assigned dead). A more detailed description of data collection and data analyses can be find in the publication "Differences in seasonal survival suggest species-specific reactions to climate change in two sympatric bat species".