Ruthrauff, Daniel R. (ORCID: 0000-0003-1355-9156) Pohlen, Zachary M. (ORCID: 0009-0001-8043-142X) Wilson, Heather M. (ORCID: 0009-0000-6387-0829) 20201015 tabular digital data Aerial Surveys of Shorebirds at Pre-migratory Staging Sites in Western Alaska, 2018-2019 ver 2.0, January 2022 Anchorage, Alaska U.S. Geological Survey, Alaska Science Center Suggested Citation: Ruthrauff, D.R., Pohlen, Z.M., and Wilson, H.M., 2020, Aerial surveys of shorebirds at pre-migratory staging sites in western Alaska, 2018-2019 (ver 2.0, January 2022): U.S. Geological Survey data release, https://doi.org/10.5066/P9ZS5Y6N https://doi.org/10.5066/P9ZS5Y6N The data in this table document the numbers of four species of shorebird counted during aerial surveys of coastal sites in western Alaska. Survey regions encompassed coastline between the mouths of the Kuskokwim and Yukon rivers, and the northern coast of the Alaska Peninsula from the mouths of the Kvichak and Naknek rivers to Nelson Lagoon. Surveys were flown from 7-9 September 2018 and 20-22 August 2019. Also provided are two Keyhole Markup Language (KML) files with the start and end points of the aerial survey transect segments, and copies of the aerial survey images from which the counts were derived. These data were collected to document the distribution and abundance of four species of shorebirds at migratory staging sites in western Alaska. 20180907 20190822 observed Complete None planned Coastal sites in western Alaska. Specifically, coastal regions from the mouth of the Kuskokwim River north to the mouth of the Yukon River, and coastal sites along the Alaska Peninsula from the mouth of the Kvichak River south to Nelson Lagoon. -168.049 -156.775 63.283 55.756 USGS Metadata Identifier USGS:ASC323 ISO 19115 Topic Category Biota Environment NASA GCMD Earth Science Keyword Thesaurus Animals/vertebrates Birds Waders/gulls/auks and allies USGS CSA Biocomplexity Thesaurus Migratory birds Aerial surveys Seasonal distribution USGS Thesaurus Wildlife Coastal ecosystems Aerial photography Migratory species None Shorebirds Bar-tailed Godwit Hudsonian Godwit Marbled Godwit Whimbrel USGS Geographic Names Information System (GNIS) Alaska Alaska Peninsula Egegik Bay Ugashik Bay Port Heiden Hook Lagoon Nelson Lagoon USGS Protected Areas Database of the United States (PAD-US) Yukon Delta National Wildlife Refuge None Bar-tailed Godwit Hudsonian Godwit Marbled Godwit Whimbrel ITIS Integrated Taxonomic Information System Unknown online database online ITIS-North America Taxonomic details retrieved October 9, 2020 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 size, shape, behavior, and patterns of flight. Taxonomy is completed for all samples. No voucher specimens were collected. Kingdom Animalia Subkingdom Bilateria Infrakingdom Deuterostomia Phylum Chordata Subphylum Vertebrata Infraphylum Gnathostomata Superclass Tetrapoda Class Aves Order Charadriiformes Family Scolopacidae Genus Limosa Species Limosa lapponica Bar-tailed Godwit TSN: 176687 Species Limosa haemastica Hudsonian Godwit TSN: 176690 Species Limosa fedoa Marbled Godwit TSN: 176686 Genus Numenius Species Numenius phaeopus Whimbrel TSN: 176599 No access constraints. No use constraints. These data are marked with a Creative Common CC0 1.0 Universal License and are in the public domain. It is requested that this USGS data release be cited for any subsequent publications that reference or utilize these data. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. 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 U.S. Fish and Wildlife Service, Migratory Bird Management, Anchorage, AK 99508 Ruthrauff, D.R. Pohlen, Z.M. Wilson, H.M. Johnson, J.A. 2021 journal article Wader Study 128(3):255-264 online International Wader Study Group Ruthrauff, D.R., Pohlen, Z.M., Wilson, H.M. and Johnson, J.A. 2021. Bar-tailed Godwits Limosa lapponica in Alaska: revisiting population estimates from the staging grounds. Wader Study 128(3):255-264. https://doi.org/10.18194/ws.00251 https://doi.org/10.18194/ws.00251 Aerial surveys were conducted by trained personnel with extensive experience identifying shorebirds and conducting aerial surveys. During surveys, observations were collected via a voice-enabled tablet linked to a GPS, and surveys were downloaded and transcribed after each flight to a digital spreadsheet. The size of each flock was estimated by the primary observer, and the secondary observer attempted to photograph each flock for later correction of flock-size estimates. We collected high resolution digital photos for use in the digital enumeration process. Photos were zoomed to allow for accurate species identification and enumeration, and we used a software-generated grid to systematically search each image. These photo-verified counts are much more accurate than counts based on estimates alone, but no formal methods (i.e., double observer counts, etc.) were employed to assess the accuracy of the digitizing process. Nearly 90% of all flocks were photographed and flock sizes manually verified via this process. For all observations of birds, an estimate of the number of individuals is presented for each observation ('best_est'), either reflecting an estimate from the primary observer ('est_num') or a count derived from a photo collected of the flock during the survey ('actual_num'). Blank cells indicate that information was not collected (e.g., situations where a flock was not seen by the primary observer but was photographed and recorded by the secondary observer) or was not relevant (e.g., no observation for start or end of transects; see Attribute Definitions for details). Values were checked for outliers and proofed for accuracy. Data set is complete. No data were omitted and there are no missing data. Positions reflect location of plane when flock was detected. Positions were determined by the survey plane's on-board GPS; accuracy estimated to be within 3 m. Horizontal positions are specified in geographic coordinates to the nearest 0.001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is World Geodetic System of 1984. Ersts, P.J. 2020 1.5.1 software online American Museum of Natural History Ersts, P.J. DotDotGoose (version 1.5.1, May 2020). American Museum of Natural History, Center for Biodiversity and Conservation. Available from https://biodiversityinformatics.amnh.org/open_source/dotdotgoose https://biodiversityinformatics.amnh.org/open_source/dotdotgoose software 2020 access date Ersts 2020 Software for digitizing and counting individual birds in photos taken during aerial surveys. FIELD: Following approaches detailed by Gill and McCaffery(1999), surveys were conducted by pilot-biologist H. Wilson of the US Fish and Wildlife Service's office of Migratory Bird Management in a Cessna 206. Surveys were conducted at speeds of approximately 100 knots at altitudes of about 150 feet. D. Ruthrauff (U.S. Geological Survey) and Z. Pohlen (U.S. Fish and Wildlife Service) served as observers, and Z. Pohlen and C. Gelasso (U.S. Fish and Wildlife Service) were secondary observers/photographers. Surveys were timed to coincide with periods when the majority of individuals from the target species were believed to be present at migratory staging sites along mudflats in western Alaska (late August / early September). Survey routes followed the coast, and were timed with daytime periods of high tides. High tides serve to group the birds into flocks that are easily detected during surveys. The four species of shorebirds detailed in this data release are large-bodied and display diagnostic plumage characteristics that facilitate easy identification by trained observers. Unknown In the evening following each day's survey, audio transcripts of aerial surveys were transcribed to a digital database that linked observations with the survey plane's GPS-flight path, a system that georeferenced each observation. The start and end of each transect were noted in the database to provide the spatial extent of the surveys. Photos collected during the surveys were downloaded and reviewed each evening as well, but photo verification did not occur until a later date due to time constraints. Ersts 2020 Unknown Prior to each day's survey, we synchronized the clocks in the plane GPS and the camera in order to facilitate linking the survey estimates with photos. We also directly transcribed photo identification numbers into the aerial survey voice transcript to further ease in linking observations. To count the individual birds in each photo, we used two software packages, 'CountThings.com' https://countthings.com/ and 'DotDotGoose' (Ersts 2020). Both packages allow users to load photos, apply a grid to each image to enable systematic searching, and digitize objects in images via mouse clicks. Both software packages allow for the counting of multiple classes of objects in each image, so we were able to count any of the four target species in each image. The software packages tally species-specific totals in each image, and export totals to a comma separated file for subsequent analysis. We saved each digitized image with species-specific colored dots highlighting individual birds for ease of future reference. Unknown LITERATURE CITED: Gill, Jr., R.E., McCaffery, B.J. 1999. Bar-tailed Godwits Limosa lapponica in Alaska: a population estimate from the staging grounds. Wader Study Group Bulletin 88:49-54. Unknown Area names are listed to describe generalized field survey locations. Point 0.001 0.001 Decimal degrees World Geodetic System of 1984 World Geodetic System of 1984 6378137 298.257223563 godwit_aerialSurvey_westernAlaska_ruthrauff_2018_2019.csv Table with aerial survey details and counts of four species of shorebirds at sites in western Alaska, 2018 and 2019. Presented in a Comma Separated Value (CSV) formatted table. Author defined year Year survey was conducted. Author defined 2018 2019 Year (YYYY) month Month survey was conducted. Author defined 8 9 Month (MM) day Day of month on which survey was conducted. Author defined 7 22 Day (DD) obs_loc Location in survey plane where primary observer was seated. Author defined frontRight Front seat, right side of plane. Author defined observer Initials of primary observer. Author defined DRR Dan R. Ruthrauff Author defined ZMP Zak M. Pohlen Author defined area Name of survey area Author defined YKD Yukon-Kuskokwim Delta Author defined AKP Alaska Peninsula Author defined transect Uniquely numbered/named transect unit Author defined Section of each survey area's coasts were delimited by unique numbers (YKD) or site names (AKP). wind_dir Direction of prevailing wind during survey period. Blank cell indicates that no information was recorded. Author defined N North Author defined NW Northwest Author defined NE Northeast Author defined W West Author defined wind_speed_kts Wind speed (knots) during survey. Blank cell indicates that no information was recorded. Author defined 5.0 15.0 Knots ceiling Condition and altitude of cloud ceiling Author defined unlimited No clouds Author defined 5000 Ceiling at 5,000 feet Author defined 2500 Ceiling at 2,500 feet Author defined 500 Ceiling at 500 feet Author defined partly cloudy Broken ceiling Author defined obs_conditions Subjective observation conditions based on ceiling, winds, tide level, etc. Author defined excellent Excellent observation conditions. Author defined tide too low Tide too low to effectively group birds, but conditions otherwise good. Author defined good Good observation conditions. Author defined ok Observation conditions less than good, but still manageable. Author defined tide Relative tide position during survey. Author defined falling Tide falling. Author defined high Tide high. Author defined rising high Tide rising and approaching high limit. Author defined low Tide low. Author defined rising Tide rising. Author defined lat Location of plane during observation, north latitude. Author defined 55.934 62.541 Decimal Degrees long Location of plane during observation, west longitude. Author defined -166.182 -157.046 Decimal Degrees gps_time Time of observation based on plane's GPS clock. Author defined 11:57:53 6:36:00 HH:mm:ss species Species observed or start/end of transect. Taxonomic details provided in the Taxonomy section of this metadata record. Author defined begin_tran Beginning point of transect. Author defined end_tran Ending point of transect. Author defined Bar-tailed Godwit Observation relating to Bar-tailed Godwit(s). Author defined Marbled Godwit Observation relating to Marbled Godwit(s). Author defined Whimbrel Observation relating to Whimbrel(s). Author defined Hudsonian Godwit Observation relating to Hudsonian Godwit(s). Author defined est_num Estimated number of bird(s) in observation. Blank cells indicate that information was not collected (e.g., situations where a flock was not seen by the primary observer but was photographed and recorded by the secondary observer) or was not relevant (e.g., no observation for start (begin_tran) or end (end_tran) of transects. Author defined 1 7000 Birds actual_num Actual number of bird(s) in observation as verified by counts derived from photo taken during survey. Blank cells indicate that information was not collected (e.g., situations where a flock was not seen by the primary observer but was photographed and recorded by the secondary observer) or was not relevant (e.g., no observation for start (begin_tran) or end (end_tran) of transects. Author defined 1 29937 Birds best_est Best estimate of bird(s) in observation. For flocks that were photo-verified, this value equals the value of 'actual_num'; for flocks without photo verification, this value equals the value of 'est_num'. Blank cells indicate that information was not collected (e.g., situations where a flock was not seen by the primary observer but was photographed and recorded by the secondary observer) or was not relevant (e.g., no observation for start (begin_tran) or end (end_tran) of transects. Author defined 1 29937 Birds image_id Filename of image (.jpg or .tif) from which count value in 'actual_num' field is derived. All images are provided in the folder "godwit_aerialSurveyImages_westernAlaska_ruthrauff_2018_2019" included with this data package. File naming convention: YYYYMMDD_TRANSECT_nn: where YYYY = survey year, MM = month, DD = day, TRANSECT = transect name or number, and nn = two-digit sequential number of image along each transect Author defined Filename of image godwit_aerialSurveyImages_westernAlaska_ruthrauff_2018_2019 Folder (with sub-folders) containing digital aerial imagery from shorebird surveys in western Alaska. Sub-folders are grouped by year and region. Each survey folder contains the digital photos from the survey flight. Photos that were enumerated using the CountThings software have dots indicating the location of each bird that was counted in the image. File naming convention: YYYYMMDD_TRANSECT_nn: where YYYY = survey year, MM = month, DD = day, TRANSECT = transect name or number, and nn = two-digit sequential number of image along each transect Author defined godwit_aerialSurveyTransects_YKDelta_ruthrauff_2018_2019.kml Keyhole Markup Language (KML) file with the start and end point of aerial survey transects along the coast of the Yukon-Kuskokwim River Delta. Author defined transect Number of the aerial survey transect segment Author defined Number of the aerial survey transect segment name Name of general geographic area of the aerial survey transect segment Author defined Name of the aerial survey transect segment LAT Latitude of start and end points of each survey transect segment (Decimal degrees). Author defined Latitude of start and end points of each survey transect segment (Decimal degrees). LON Longitude of start and end points of each survey transect segment (Decimal degrees). Author defined Longitude of start and end points of each survey transect segment (Decimal degrees). godwit_aerialSurveyTransects_AKPeninsula_ruthrauff_2018_2019.kml Keyhole Markup Language (KML) file with the start and end point of aerial survey transects along the north coast of the Alaska Peninsula. Author defined transect Name of the aerial survey transect segment Author defined Name of the aerial survey transect segment lat Latitude of start and end points of each survey transect segment (Decimal degrees). Author defined Latitude of start and end points of each survey transect segment (Decimal degrees). long Longitude of start and end points of each survey transect segment (Decimal degrees). Author defined Longitude of start and end points of each survey transect segment (Decimal degrees). start_end Label for the start or end of each survey transect segment. Author defined BEGT Label for the start of each survey transect segment. Author defined ENDT Label for the end of each survey transect segment. Author defined 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, KML, JPG Tabular data in CSV format; Spatial data in KML format; Aerial images in JPG format; FGDC metadata in XML and HTML formats. https://doi.org/10.5066/P9ZS5Y6N None 20250422 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