Rode, Karyn D. (ORCID: 0000-0002-3328-8202) Douglas, David C. (ORCID: 0000-0003-0186-1104) Atwood, Todd C. (ORCID: 0000-0002-1971-3110) Durner, George M. (ORCID: 0000-0002-3370-1191) Wilson, Ryan R. (ORCID: 0000-0001-7740-7771) Bromaghin, Jeffery F. (ORCID: 0000-0002-7209-9500) Pagano, Anthony M. (ORCID: 0000-0003-2176-0909) Simac, Kristin (ORCID: 0000-0002-4072-1940) 20221031 tabular digital data Anchorage, Alaska U.S. Geological Survey, Alaska Science Center Suggested Citation: Rode, K.D., Douglas, D.C., Atwood, T.C., Durner, G.M., Wilson, R.R., Bromaghin, J.F., Pagano, A.M., Simac, K., 2022, Polar bear Continuous Time-Correlated Random Walk (CTCRW) location data derived from satellite location data, Chukchi and Beaufort Seas, July-November 1985–2017: U.S. Geological Survey data release, https://doi.org/10.5066/P9XEOBWV https://doi.org/10.5066/P9XEOBWV This dataset consists of one table with estimated locations of adult female polar bears during July-November 1985-2017, used for quantifying changes in summer land use over time. Locations were estimated with a Continuous Time-Correlated Random Walk (CTCRW) model fit to satellite tracking from radio-collared adult female polar bears. All bears included in this data set were captured and instrumented in the Beaufort or Chukchi Sea. These data were used to estimate trends in land use patterns of polar bears in response to changing sea ice conditions. These data were gathered as part of on-going long-term research by the U.S. Geological Survey in the Beaufort Sea and the U.S. Fish and Wildlife Service in the Chukchi Sea to understand the ecology and behavior of polar bears and their seasonal use of terrestrial and sea ice habitats. 19850701 20171130 observed Complete None planned Beaufort and Chukchi Seas 144.0864 -111.104 83.901 63.383 USGS Metadata Identifier USGS:ASC491 ISO 19115 Topic Category Biota Environment NASA GCMD Earth Science Keyword Thesaurus Animals/Vertebrates Mammals Carnivores Bears Species Life History Use/Feeding habitat Telemetry USGS CSA Biocomplexity Thesaurus Marine mammals Threatened species USGS Thesaurus Wildlife Coastal ecosystems Marine ecosystems Animal behavior Biogeography None Satellite Transmitter Argos PTT GPS Polar bear Ursus maritimus USGS Geographic Names Information System (GNIS) Alaska Beaufort Sea None Animals Mammals Vertebrates Carnivore ITIS Integrated Taxonomic Information System Unknown online database online ITIS-North America Taxonomic details retrieved April 21, 2023 from the Integrated Taxonomic Information System online database https://www.itis.gov https://doi.org/10.5066/F7KH0KBK Species were identified by skilled observers in the field based on general appearance. Polar bears are not easily confused with other species. Taxonomy is complete for all samples. No voucher specimens were collected. Kingdom Animalia Subkingdom Bilateria Infrakingdom Deuterostomia Phylum Chordata Subphylum Vertebrata Infraphylum Gnathostomata Superclass Tetrapoda Class Mammalia Subclass Theria Infraclass Eutheria Order Carnivora Suborder Caniformia Family Ursidae Genus Ursus Species Ursus maritimus Polar Bear TSN: 180542 No access constraints. No use constraints. We request that the suggested citation of this USGS data release be included in any publications that reference or utilize these data. U.S. Geological Survey, Alaska Science Center Mailing and Physical

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Anchorage Alaska 99508 USA 907-786-7000 gs-ak_asc_datamanagers@usgs.gov Rode, K.D. Douglas, D.C. Atwood, T.C. Durner, G.M. Wilson, R.R. Pagano, A.M. 2022 journal article Global Ecology and Conservation 40:e02319 online Elsevier Rode, K.D., Douglas, D.C., Atwood, T.C., Durner, G.M., Wilson, R.R., Pagano, A.M., 2022., Observed and forecasted changes in land use by polar bears in the Beaufort and Chukchi Seas, 1985–2040. Global Ecology and Conservation 40:e02319. https://doi.org/10.1016/j.gecco.2022.e02319 https://doi.org/10.1016/j.gecco.2022.e02319 We used a continuous time-correlated random walk (CTCRW) model to estimate polar bear locations every 6 hr at 00:00, 06:00, 12:00, and 18:00 Coordinated Universal Time (UTC) based on the Argos and subsampled-GPS locations. The CTCRW model provides standard error estimates for the average estimated locations based on the estimated error for Argos Location Classes and GPS locations, and the elapsed time differences between the sequential empirical tracking locations. Attribute values fall within expected ranges. No CTCRW model estimated locations were generated for periods when the elapsed time between sequential tracking locations exceeded fourteen days. Details of the criteria used to filter the Argos locations prior to entry to the CTCRW model are provided in the Methodology and Process Steps sections of this metadata record. All polar bear satellite locations collected between 1986–2003 were Doppler-shift derived and estimated by the Argos system (CLS; https://www.argos-system.org/manual/ ). The data were filtered by the Douglas Argos-filter (DAF) algorithm (Douglas et al 2012) distance-angle-rate algorithm (MAXREDUN = 10 km, MINRATE = 10 km/hr ). Douglas et al. (2012) estimated the 68th percentile for the horizontal error of post-filtered Argos location classes 3, 2, 1, 0, A, B and Z as, respectively, 0.4, 1.0, 2.5, 6.8, 4.1, 7.6, and 4.7 km. Most polar bear locations collected after 2003 were derived by on-board global positioning system (GPS) receivers whose horizontal accuracy has been estimated as 30 m (Adams et al. 2013). We did not filter GPS locations. GPS location error estimates were used in CTCRW modeling described below. Adams, A.L. Dickinson, K.J.M. Robertson, B.C. van Heezik, Y. 2013 journal article PLoS One 8(7):e68496 online PLoS One Adams, A.L., Dickinson, K.J.M., Robertson, B.C., van Heezik, Y. 2013. An evaluation of the accuracy and performance of lightweight GPS collars in a suburban environment. PLoS ONE 8(7):e68496 doi:10.1371/journal.pone.0068496 https://doi.org/10.1371/journal.pone.0068496 journal article 2013 publication date Adams et al 2013 Describes the use of the horizontal accuracy of on-board geographic positioning system (GPS) receivers. Douglas, D.C. Weinzierl, R. Davidson, S.C. Kays, R. Wikelski, M. Bohrer, G. 2012 journal article Methods in Ecology and Evolution 3:999-1007 Online John Wiley and Sons, Inc. Douglas, D.C., Weinzierl, R., Davidson, S.C., Kays, R., Wikelski, M., Bohrer, G. 2012. Moderating Argos location errors in animal tracking data. Methods in Ecology and Evolution 3:999-1007 doi:10.1111/j.2041-210X.2012.00245.x https://doi.org/10.1111/j.2041-210X.2012.00245.x journal article 2012 publication date Douglas et al 2012 Describes the use of the "Douglas Argos Filter" (DAF) for flagging implausible locations. Durner, G.M. Douglas, D.C. Nielson, R.M. Amstrup, S.C. McDonald, T.L. Stirling, I. Mauritzen, M. Born, E.W. Wiig, Ø. DeWeaver, E. Serreze, M.C. Belikov, S.E. Holland, M.M. Maslanik, J. Aars, J. Bailey, D.A. Derocher, A.E. 2009 journal article Ecological Monographs 79(1):25-58 online Ecological Society of America Durner, G.M., Douglas, D.C., Nielson, R.M., Amstrup, S.C., McDonald, T.L., Stirling, I., Mauritzen, M., Born, E.W., Wiig, Ø., DeWeaver, E., Serreze, M.C., Belikov, S.E., Holland, M.M., Maslanik, J., Aars, J., Bailey, D.A., Derocher, A.E. 2009. Predicting 21st-century polar bear habitat distribution from global climate models. Ecological Monographs 79(1):25-58. doi:10.1890/07-2089.1 https://doi.org/10.1890/07-2089.1 journal article 2009 publication date Durner et al 2009 Describes the use of the deployment and tracking data from satellite radio-collared polar bears. Johnson, D.S. London, J.M. Lea, M.-A. Durban, J.W. 2008 journal article Ecological Monographs 79(1):25-58 online Ecological Society of America Johnson, D.S., London, J.M., Lea, M.-A., Durban, J.W. 2008. Continous-time correlated random walk model for animal telemetry data. Ecology 89(5):1208-1215. doi:10.1890/07-1032.1 https://doi.org/10.1890/07-1032.1 journal article 2008 publication date Johnson et al 2008 Describes the use of a continuous time-correlated random walk (CTCRW) model to predict locations on standard intervals. Olson, J.M. Rode, K.D. Eggett, D. Smith, T.S. Wilson, R.R. Durner, G.M. Fischbach, A. Atwood, T.C. Douglas, D.C. 2017 publication Olson, J.M., Rode, K.D., Eggett, D., Smith, T.S., Wilson, R.R., Durner, G.M., Fischbach, A., Atwood, T.C., Douglas, D.C. 2017. Collar temperature sensor data reveal long-term patterns in southern Beaufort Sea polar bear den distribution on pack ice and land. Marine Ecology Progress Series 564:211-224. doi:10.3354/meps12000 https://doi.org/10.3354/meps12000 journal article 2017 publication date Olson et al 2017 Describes the identification of winter maternal denning events in polar bears using collar temperature sensor data. R Core Team 2018 application/service R Core Team. 2018. R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna. https://www.R-project.org Digital and/or Hardcopy 2018 publication date R Core Team Software used to run the continuous time-correlated random walk (CTCRW) model (Johnson et al. 2008) to estimate locations on a 6-hour interval at 00:00, 06:00, 12:00, and 18:00 Coordinated Universal Time (UTC) based on the filtered Argos and GPS locations. The R package 'crawl', version 2.2.3, was used for the CTCRW modeling. METHODS - FIELD: From 1985 to 2017, biologists captured adult female polar bears in the southern Beaufort Sea and Chukchi Sea and equipped them with collar platform transmitter terminals (PTTs) that provided Doppler-derived or GPS locations. Collars additionally recorded temperature and activity sensor data. We restricted our analysis to data from radio-collared adult female polar bears because adult male and sub-adult polar bears cannot wear radio collars, and the vast majority of tracking data has been of adult females (Durner et al 2009). Unknown Raw tracking data were obtained through the Argos System (www.argos-system.org) or the Iridium satellite system (Iridium Satellite Communications, McLean, VA, USA). Unknown All polar bear satellite locations collected between 1985–2003 were Doppler-shift derived and estimated by the Argos system (CLS; https://www.argos-system.org/manual/ ). We performed an initial filter to remove implausible Doppler locations using the Douglas Argos-filter (DAF) algorithm (Douglas et al. 2012). DAF retained all standard-quality locations (Argos location classes 3, 2, and 1), and auxiliary location classes (0, A, B and Z) when corroborated by a consecutive location within a 10 km radius, or when movement rates were <10 km hr-1 and the internal angles (α, in degrees) formed by preceding and subsequent vectors (of lengths d1 and d2 km) were not suspiciously acute (α > -25 + β × ln[minimum (d1,d2)], where β = 15). We assigned β = 15 because it performed well for our specific tracking data across seasons and regions. Most polar bear locations collected after 2003 were derived by on-board global positioning system (GPS) receivers whose horizontal accuracy has been estimated as 30 m (Adams et al 2013). Argos locations collected after 2003 were also filtered as described above. To standardize location intervals across all annual tracking data subsets, we used continuous time-correlated random walk (CTCRW) model to estimate a single location every 6 hr at 00:00, 06:00, 12:00, and 18:00 Coordinated Universal Time (UTC) based on the filtered Argos and GPS locations. The CTCRW model further provides standard error estimates for the average estimated locations based on the estimated error for Argos Location Classes and GPS locations, and the elapsed time differences between the sequential empirical tracking locations. Unknown LITERATURE CITED: Cuffney, T.F., Gurtz, M.E., Meador, M.R., 1993. Guidelines for the processing and quality assurance of benthic invertebrate samples collected as part of the National Water-Quality Assessment Program: U.S. Geological Survey Open-File Report 93-407, https://doi.org/10.3133/ofr93407 Merritt, R.W., Cummins, K.W., Berg, M.B., 2008. An Introduction to the Aquatic Insects of North America 4th edition, Kendall Hunt Inc., Dubuque, IA Unknown Point 0.0001 0.0001 Decimal degrees World Geodetic System of 1984 (WGS84) World Geodetic System of 1984 (WGS84) 6378137 298.257223563 polarBear_CTCRW_Locations_ChukchiAndBeaufortSea_1985-2017.csv Table containing continuous time-correlated random walk (CTCRW) estimated locations (geographic latitude/longitude WGS84) during the months of July-November, derived from satellite location data from adult female polar bears captured in the Beaufort and Chukchi seas, 1985–2017. Presented in a Comma Separated Value (CSV) formatted table. Author defined UniqueAnimalID A unique identifier assigned to each bear in the dataset. Author defined 1 541 none timestamp The date and time associated with the CTCRW model-derived location coordinates, Coordinated Universal Time (UTC). Author defined 1985-07-01 00:00:00 2017-11-30 18:00:00 Date and time (YYYY-MM-DD HH:MM:SS; UTC) mu_lat Estimated latitude derived by the CTCRW model for the given timestamp. Author defined 63.3830 83.9014 Decimal degrees (WGS84; EPSG:4326) mu_lon Estimated longitude derived by the CTCRW model for the given timestamp. Author defined -179.9999 179.9998 Decimal degrees (WGS84; EPSG:4326) se_mu_x Standard error of the average estimated location (mu_lon and mu_lat) by the CTCRW model based on the estimated error for the Argos Location Classes and GPS locations, and the elapsed time differences between the sequential empirical tracking location data. Author defined 11 66766 Meters se_mu_y Standard error of the average estimated location (mu_lon and mu_lat) by the CTCRW model based on the estimated error for the Argos Location Classes and GPS locations, and the elapsed time differences between the sequential empirical tracking location data. Author defined 11 66766 Meters U.S. Geological Survey USGS ScienceBase Team Mailing and Physical

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Denver Colorado 80225 USA 1-888-275-8747 sciencebase@usgs.gov The U.S. Geological Survey, Alaska Science Center is the authoritative source of these data, distributed by ScienceBase (a USGS Trusted Digital Repository). Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data for other purposes or on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. CSV Tabular data in CSV format; FGDC metadata in XML and HTML formats. https://doi.org/10.5066/P9XEOBWV None 20250109 U.S. Geological Survey, Alaska Science Center Mailing and Physical

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Anchorage Alaska 99508 USA 907-786-7000 gs-ak_asc_datamanagers@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata (CSDGM) FGDC-STD-001.1-1999