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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...
The imagery and annotations presented here were generated while testing an aerial photographic survey design to improve repeatability, transparency, and estimation of variance for annual population estimates of geese staging at Izembek Lagoon, Alaska. This dataset includes 1) 131,031 .JPG images captured from a small fixed-wing occupied aircraft, usually at an altitude of about 457 m, over Izembek Lagoon; 2) annotations of objects (geese, ducks, and gulls) assigned by an automated algorithm, and 3) manually corrected annotations that were edited by project staff for only those photos automatically identified as containing geese of any species. The photos were captured at predetermined points to systematically sample...
This dataset provides an orthorectified aerial photo mosaic derived from airborne fodar data acquired in 2021 on August 31 over the Totatlanika River in central Alaska. The term “fodar” is a portmanteau of foto and lidar, coined by Matt Nolan, which describes a method of quantifying the color and elevation of Earth’s surface via airborne small-format digital camera photography.
Categories: Data,
Image;
Tags: Alaska,
Alaska Range,
Buzzard Creek,
California Creek,
DIGITAL ELEVATION/TERRAIN MODEL (DEM),
These are geospatial data that characterize the distribution of polar bear denning habitat on the National Petroleum Reserve–Alaska (NPR-A), the 1002 Area of the Arctic National Wildlife Refuge and the coastal plain of northern Alaska between the Colville River and the Alaska/Canada border.
This dataset is one table with results of tests to determine exposure of Chukchi Sea polar bears to a suite of pathogens. Results are serological tests for antibodies and tests of fecal samples for presence of parasites. Serologic assays were conducted for Toxoplasma gondii, Neospora caninum, Francisella tularensis, Coxiella burnetii, Leptospira spp., Brucella canis, Brucella abortus/suis, and canine distemper virus. Parasitology analyses were conducted for presence of Giardia cysts and Cryptospiridium oocysts in fecal samples. Polar bears were sampled on sea ice in the Chukchi Sea between mid-March and early May 1987-1994 and 2008-2017. The dataset includes relevant information about the bears that were captured...
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.
These data were part of a pilot tracking study of three adult female caribou from the Fortymile Herd in Alaska. The dataset is comprised of two comma separated values (.csv) files. Data includes: 1) processed (i.e., erroneous locations removed) GPS locations for caribou, received once per hour for 6 months (October 1998 to April 1999), and 2) spatial, temporal, and biological attributes of three female caribou tracked during the study.
This data release is composed of seven datasets regarding colonial seabirds and forage fish at two seabird nesting colonies on Gull and Chisik Islands in lower Cook Inlet, Alaska. These data were collected to detect changes in the breeding population of Black-legged Kittiwakes and Common Murres on two nesting colonies in lower Cook Inlet and to compare those counts to baseline counts from 1995-1999. They are part of an ongoing study in lower Cook Inlet, Alaska to assess the recent status of forage fish and seabirds (2000-2020).
This dataset contains isotope results of stable isotope (δ13C and δ15N) and radicoarbon (F14C) analyses of muscle tissue from fish collected in the nearshore Beaufort Sea, Alaska in summers 2017-2019.
This data package includes 17,014 pairs of raster geotiffs. Each pair is made up of two geotiff rasters derived from historical observations from Landsat satellites (04-09) over the Yukon, Kuskokwim, and Tanana rivers in Alaska. One raster reports estimated mid-day water surface temperature (ST) in degrees Celsius (deg_Cc). The second raster reports the surface temperature quality assessment (sST_QA_c) and provides the ST product uncertainty (also in degrees). The period of observation is May through October for the years 1984-2022.
This dataset consists of one table with annual nesting productivity estimates for Black-legged Kittiwakes and Common Murres at two seabird nesting colonies on Gull and Chisik Islands in lower Cook Inlet, Alaska.
These data are serum urea nitrogen and creatinine levels for polar bears captured in the southern Beaufort Sea 1983-2016 and the Chukchi Sea 1987-1993. The dataset includes relevant information about the bears that were captured including the latitude and longitude of their capture location, capture date, age class and sex, the age and number of cubs accompanying an adult female, and whether the bear denned during the previous winter or exhibited signs of being engaged in mating behavior at the time of or just prior to capture.
Categories: Data;
Types: Citation;
Tags: Beaufort Sea,
Chukchi Sea,
animals/vertebrates,
behavior,
biota,
These data are the data for spring body composition and energy content for adult female brown bears from Gates of the Arctic, Lake Clark, Kodiak, and Katmai, Alaska, 2014-2017.
This data package presents legacy data on Emperor Goose, Cackling Goose, Black Brant, and Greater White-fronted Goose, breeding biology, behavior, and morphology collected at study sites near Kokechik Bay on the Yukon Delta National Wildlife Refuge (previously Clarence Rhodes National Wildlife Refuge), Alaska during the summers of 1982 through 1988. These data were collected to provide a basis for the evaluation of long-term changes in Emperor Goose and other waterfowl biology on the Yukon-Kuskokwim Delta, Alaska.
This dataset consists of one table with Area Backscattering Coefficient (ABC) data from hydroacoustic transect surveys collected around two seabird nesting colonies on Gull and Chisik Islands in lower Cook Inlet, Alaska.
Categories: Data;
Tags: Acoustic backscatter,
Alaska,
Aquatic Sciences and Fisheries,
Biota,
Coastal ecosystems,
This dataset consists of sample details and radiocarbon age data of tree-ring samples collected near Girdwood, Alaska, and analyzed at the National Ocean Sciences Accelerator Mass Spectrometry Facility.
These data include water chemistry from headwater streams to large rivers that have recently turned orange and reference rivers that have not. These samples were collected in two national parks in Arctic Alaska: Kobuk Valley National Park, and Noatak National Preserve.
Since the late 1950s, the USGS has maintained a long-term glacier mass-balance program at three North American glaciers. Measurements began on South Cascade Glacier, WA in 1958, expanding to Gulkana and Wolverine glaciers, AK in 1966, and later Sperry Glacier, MT in 2005. The Juneau Icefield Research Program has measured surface mass balance on Lemon Creek and Taku Glacier since the mid-1940s, with USGS providing complimentary seasonal measurements of Lemon Creek beginning in 2014 (JIRP; Pelto and others, 2013). Direct field measurements of point glaciological data are combined with weather and geodetic data to estimate the seasonal and annual mass balance at each glacier in both a conventional and reference surface...
These data are part of the Gulf Watch Alaska (GWA) long-term monitoring program and describe bivalve count and size sampling and observations conducted at intertidal soft-sediment sampling sites in the northern Gulf of Alaska. This dataset consists of five comma separated files (.csv): 1) bivalve taxonomy table, 2) bivalve sampling site table, 3) bivalve count table, 4) bivalve size table, and 5) list of Gulf Watch Alaska principal investigators and collaborators.
These data are in two tables relating to fall age ratios (number of juvenile birds : total birds aged) of Black Brant (Branta bernicla nigricans) staging in Izembek Lagoon, Alaska, since 1963. The first table is observation data for the age classes of Black Brant during surveys, and associated survey characteristics. The second table contains model-based estimates of age ratios by year along with Standard Error (SE), and 95% Bayesian credible intervals around estimates.
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