Data from: Male long-distance migrant turned sedentary; The West European pond bat (Myotis dasycneme) alters their migration and hibernation behaviour

Winter survey data, temperature data and mark recapture data of Myotis dasycneme. This study aimed to better understand the migration, mating and hibernation choices of the pond bat. The study area covered the whole of the Netherlands, Belgium and East Frisia (northwest Germany). We defined two study periods, data collected between 1930 and 1980 (Sluiter and van Heerdt) and data between 1980 and 2015 (Haarsma). All available mark and recovery data (ringing) of both the historical and recent migration research were digitized. Observations include location and date of capture, species, sex and ring number. The latest observations in the recent dataset (Haarsma) also include biometric measurements (forearm length, body mass) and information about age and reproductive status. These biometric measurements show that male pond bats are on average smaller and lighter than females (body mass (g)/ forearm length (mm) females: 18.9/47.1, males: 16.4/46.4). The dataset shows changes in the fat mass of both sexes during a year. This study also compares migration data with winter monitoring survey data. We selected winter roosts with three or more records of three or more pond bats in one or both of the study periods. Only data from sites with long-term data series (from the hibernacula in the Dutch provinces of Zuid-Holland, Gelderland and Limburg) were used to analyse trends and annual abundance. Our selection included 59 limestone mines in the province of Limburg and 16 WOII bunkers in Gelderland and 38 in Zuid-Holland. We divided the sites into 'core' and 'satellite' sites depending on the timing of first colonization. Bunker limestone mine microclimate Radiation temperature: radiation temperature of the wall, measured with a non-contact infrared thermometer How many bats: the group size of each bat/ group of bats observed, categorized as alone and group. Where: the hanging location of the observed bat, categorized as hidden (in crevice) or free (free on ceiling or wall) Date: date of the observation Xy-coord: The coordinates of the entrance of the bunker or limestone mine. The RD (Rijks-Driehoek) system is the coordinate system used by the Dutch geographical service. Type: Bunker or limestone Location description: description of the name of the site Bunker monitoring core and satellite Date: date Winter: the period between September and April is defined as the winter of the year starting in January. Location description: description of the name of the site N of pond bats: total number of observed pond bats Province: the province Type: hibernacula categorized as a core or satellite site, sites occupied by pond bats since 1977 and 1997 respectively. XY-coord: The coordinates of the entrance of the bunker or limestone mine. The RD (Rijks-Driehoek) system is the coordinate system used by the Dutch geographical service. Supporting information (as referenced in the published paper, hence also available with plos one) S1 Fig. The range of the West European pond bat population (TIF). The shaded areas indicate the areas where the bulk of the surveys were carried out. S2 Fig. The distribution of the pond bat in Europe (country boundaries are only indicative) (JPG). Within the whole range of the species distribution seven groups can be separated. A The Netherlands, Belgium and Northwest Germany (~the West European population), B Jutland Peninsula, C Central European lakelands, D The Baltic States, E Ural Mountains (hibernacula), F Volga Valley (summer nurseries), G Hungary and Romania. S3 Fig. The distribution of hibernacula used by the western pond bat population (TIF). These are sites with three or more records of pond bats in one or both study periods. We identified four roost categories: Roosts which have been used ever since 1900 (= green squares), roosts used only between 1900–1980 (= open black squares), roosts occupied after 1980 (= purple circles), roosts occupied after 1997 (= blue asterisks). Detailed maps, all with the same enlargement, of the clusters in the provinces of Zuid-Holland (1), Gelderland (1) and Limburg (3) are provided. S1 Table. Summary of the average weight of pond bats over the study period. The weight is averaged per week. The table gives average weight of females, males both adults and juveniles. Avg weight: average weight of pond bats of each sex, in a certain week Sex: male of female Week number: number of the week Age: juvenile (or young of the year). Defined as the from birth until the onset of first hibernation. Subadult or sexual immature, defined as individuals with no signs of (past) reproductive activity. Adult or sexual mature, defined as all individuals with signs of (previous) reproductive activity. N observations: number of observations within each subset. S2 Table. Mark and recapture data from the historical dataset. Ringnumber: the label of the ring Sex: male or female capture date: date of capture capture location: description of capture location x y coordinate: The coordinates of the capture location in RD. The RD (Rijks-Driehoek) system is the coordinate system used by the Dutch geographical service. recapture date: date of recapture recapture location: description of recapture location x y coordinate: The coordinates of the recapture location in RD. The RD (Rijks-Driehoek) system is the coordinate system used by the Dutch geographical service. S3 Table. Mark and recapture data from the recent dataset. Same dataset as the historical set, but now including age (see definition used in S1