These data represent estimates of den entrance and exit dates for female polar bears in the southern Beaufort and Chukchi Seas based on temperature sensor data obtained from satellite collars. An algorithm described in Olson et al. (2017) was used to determine whether the female entered a den and further analyses using temperature data as described in Olson et al. (2017) were used to assess den entry and emergence dates. The algorithm used identified the denning period as that during which collar temperature remained consistently above a temperature threshold. As such, users of these data should be aware that bear behavior can affect den entrance and exit date. If a bear moves in and out of a den frequently, the algorithm identifies that bear as not denning. Den substrate was determined by examining satellite locations from collars during the identified denning period and classify dens as occurring on landfast ice, pack ice, or land. This data set also includes direct observations of females post-den emergence to ascertain whether or not she was accompanied by cubs as an indicator of reproductive success. The den IDs provided in this data set correspond with those identified in the USGS den catalog (Durner 2010, Durner et al 2020) additional information about the dens in this data set may be found in the catalog.

This dataset contains specific activity measures of deuterium oxide and oxygen-18, body mass, and blood biochemistry (blood urea nitrogen and creatinine) data for 9 female polar bears without dependent young in the southern Beaufort Sea in April 2014-2016.

These were data collected from polar bears from the southern Beaufort Sea during the spring between 2004 and 2016. Data include individual bear identification, age and sex class, capture date, capture year, open water season lengths, melt season length, and diet composition (expressed as a percentage of prey species). These data were used to determine whether polar bear diets have recently changed or remained stable over time.

This dataset includes measures collected on polar bears captured in the Chukchi and Beaufort Seas, 1981-2017 by the U.S. Geological Survey and U.S. Fish and Wildlife Service. Data collected include body length, body mass, axillary girth, skull width and tail lengths. Bears were also aged as described in the methods. For some bears, an adipose tissue sample was collected and percent lipid content was measured, percent body fat was measured via bioelectrical impedance analysis, and/or recent feeding behavior was assessed via gut palpitation or blood urea and creatinine levels, all of which are further described in the methods.

This dataset is one table with data collected and derived from polar bears sampled in Alaska's southern Beaufort Sea during 2015-2019. Data include demographic and morphometric information from each sampled polar bear, gut microbiome diversity indices derived from fecal DNA metabarcoding, and the proportion of prey species detected in individual bear diets derived from quantitative fatty acid analysis (QFASA). The presence of prey items in the diet of polar bears was also assessed using fecal DNA metabarcoding. Note that cetacean data obtained via DNA metabarcoding was not analyzed and is not presented in this data release. Only southern Beaufort Sea population data are included in this USGS data release. All DNA sequence data have been submitted to the NCBI Short Read Archive (accession bioproject ID: PRJNA773176).

This dataset is one table with time-linked behavior data derived from video camera collars on polar bears on land near Churchill, Manitoba, Canada. Eighteen polar bears were equipped with video-camera collars (Vertex Plus collar with camera option, Vectronic Aerospace GmbH, Berlin, Germany) for 19 - 23 days in 2019, 2021, and 2022.

This dataset is one table with demographic, morphometric, and blood analyte measurements from whole blood and serum samples taken from a subset of polar bears sampled in Alaska's southern Beaufort Sea during 1989-2012. The measured blood analytes include: blood urea nitrogen, creatinine, glucose, total protein, hemoglobin, red blood cell count, packed cell volume, and hemoglobin A1c (HbA1c).

This dataset is one table with archival logger data containing measures of tri-axial acceleration and ambient temperature measured at 16 Hz in collars (Vertex Plus collar with camera option, Vectronic Aerospace GmbH, Berlin, Germany) attached to 20 polar bears that were instrumented on land near Churchill, Manitoba, Canada for 19 - 23 days in 2019, 2021, and 2022.

This data set is one table with observations of polar bears located during aerial surveys along the coast and barrier islands of the southern Beaufort Seas during fall, 2010-2013. Survey flights were conducted using A-Star B2 and Bell 206 helicopters at an average altitude of 300 feet AGL and an average speed of 50 miles per hour. Survey crews searched for polar bears using coastal and inland transects and over-flights of all coastal barrier islands.

This dataset contains measures of oxygen consumption from an adult female polar bear resting in a metabolic chamber.