Data from: Aquatic behaviour of polar bears (Ursus maritimus) in an increasingly ice-free Arctic

Three data files associated with the manuscript "Aquatic behaviour of polar bears (Ursus maritimus) in an increasingly ice-free Arctic". Data was collected by devices with a saltwater switch (and for diving, a pressure sensor) deployed on collars of female polar bears in Svalbard in 2005-2017. 1) Monthly_means.txt is a tab-separated text file with 818 records with the following columns: "id" (individual bear identifier), "month" (1-12), "year", "mean_proportion_wet" (monthly mean proportion of the time the collar recorded being submerged in water), "days" (length of recorded time this mean is based on, minimum 5 days), "reproductive_status" (whether the female had young of the year (c), yearlings (y), no cubs (n) in the preceeding april, or if this is not known (NA)), "offshore" (whether the bear made offshore excursions or not during their period of tracking). 2) Dive_depths.txt is a tab-separated text file with 51301 records with the following columns: "id" (individual bear identifier), "dtime" (timestamp, GMT), "swim_duration" (swim duration in seconds), "max_depth" (maximum recorded depth during a swim, in meters), "download_type" (if this record was transmitted over the ARGOS network (giving an unbiased sample of dives) or downloaded directly from a recovered collar (giving a complete record)). 3) Swimming_iceconc.txt is a tab-separated text file with 51301 records with the following columns: "id" (individual bear identifier), "dtime" (timestamp, GMT), "proportion_wet" (2 hour summary of proportion of time in water, centered on timestamp), "ice_concentration" (sea ice concentration in percent).本数据集关联于学术论文《海冰逐渐消融的北极地区北极熊（Ursus maritimus）的水生行为》。数据由2005年至2017年间，部署于斯瓦尔巴群岛雌性北极熊项圈上的采集设备获取：该类设备搭载盐水开关（saltwater switch），针对潜水监测需求还额外配备了压力传感器（pressure sensor）。 数据集包含3个数据文件： 1. **Monthly_means.txt**：为制表符分隔文本文件，共包含818条记录，字段包括："id"（个体北极熊识别码）、"month"（月份，取值范围1至12）、"year"（年份）、"mean_proportion_wet"（项圈记录的月度平均浸水时长占比）、"days"（计算该平均值所依据的有效记录时长，最短为5天）、"reproductive_status"（雌性个体在对应年份4月的繁殖状态：带当年幼崽（c）、带一岁幼崽（y）、无幼崽（n），或状态未知（NA））、"offshore"（追踪期间该北极熊是否开展离岸活动）。 2. **Dive_depths.txt**：为制表符分隔文本文件，共包含51301条记录，字段包括："id"（个体北极熊识别码）、"dtime"（格林尼治标准时间戳）、"swim_duration"（游泳时长，单位：秒）、"max_depth"（单次游泳过程中记录的最大深度，单位：米）、"download_type"（数据下载类型：通过ARGOS网络传输的记录（可获得无偏潜水样本），或从回收项圈直接下载的记录（可获得完整潜水记录））。 3. **Swimming_iceconc.txt**：为制表符分隔文本文件，共包含51301条记录，字段包括："id"（个体北极熊识别码）、"dtime"（格林尼治标准时间戳）、"proportion_wet"（以时间戳为中心的2小时浸水时长占比汇总值）、"ice_concentration"（海冰覆盖率，单位：百分比）。