Kloecker, Kimberly A. (ORCID:0000-0002-2461-968X) Esslinger, George G. (ORCID:0000-0002-3459-0083) Monson, Daniel H. (ORCID:0000-0002-4593-5673) 20240321 tabular digital data Anchorage, Alaska U.S. Geological Survey, Alaska Science Center Suggested Citation: Kloecker, K. A., Esslinger, G.G., and Monson, D.H., 2024, Glacier Bay National Park and Preserve sea otter forage data, 1993-2019: U.S. Geological Survey data release, https://doi.org/10.5066/P9T6UB5G https://doi.org/10.5066/P9T6UB5G These data describe observations of sea otter foraging behavior in Glacier Bay National Park and Preserve. Data consist of dive and surface times, success in prey retrieval, prey item, prey quantity, and size. Additionally, location of observations, and age class, sex, and pup status of the focal sea otter were also recorded. The purpose of these data was to allow comparison of a set of sea otter forage data metrics across time and geographic location. Metrics include: foraging success rate, composition of prey, mean size and/or size frequency distribution of common prey, number of prey items per dive, and energy intake rate. Comparisons include metrics from one location over time or from one time across locations. 1993 2019 ground condition Complete None planned Glacier Bay National Park and Preserve -137.1533 -135.6702 59.0857 58.3008 USGS Metadata Identifier USGS:ASC609 ISO 19115 Topic Category Biota Environment NASA GCMD Earth Science Keyword Thesaurus Animals/Vertebrates Animals/Invertebrates Marine environment monitoring USGS CSAS Biocomplexity Thesaurus Foraging behavior Prey Marine ecology Coastal ecosystems Prey selection USGS Thesaurus Wildlife Macroinvertebrates Benthic ecosystems Coastal ecosystems Marine ecosystems None Sea otters Enhydra lutris Marine benthic invertebrates USGS Geographic Names Information System (GNIS) Alaska Gulf of Alaska Protected Areas Database of the United States (PAD-US) Glacier Bay National Park and Preserve None Sea otters Enhydra lutris ITIS Integrated Taxonomic Information System Unknown online database online ITIS-North America Taxonomic details retrieved February 28, 2024, from the Integrated Taxonomic Information System online database https://www.itis.gov https://doi.org/10.5066/F7KH0KBK World Register of Marine Species (WoRMS) Unknown online database online WoRMS Editorial Board Taxonomic details retrieved February 28, 2024, from the World Register of Marine Species online database https://www.marinespecies.org https://doi.org/10.14284/170 Prey species were identified by trained observers in the field using physical characteristics. Prey were identified while the otter was handling the items at the water's surface. Observers use binoculars (10x42) and spotting scopes (field model scope, Questar Corp, New Hope, PA) to note identifying features of prey as well as characteristic handling methods that assist in identification. Provided in table "GLBA_SEOT_forage_taxonomy_1993-2019.csv" is the classification of marine invertebrates and vertebrates to the taxonomic rank of phylum, class, order, family, genus, or species. Prey items are varied and often not identified to species so broader groupings are used when applicable. Sea otters consume a wide variety of prey, primarily benthic invertebrates from hard and soft substrates, but also fish such as sand lance or lumpsuckers on occasion. Often prey cannot be identified and is entered as 'uni' for unidentifiable. 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 Mustelidae Subfamily Lutrinae Genus Enhydra Species Enhydra lutris Subspecies Enhydra lutris kenyoni 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

4210 University Drive

Anchorage Alaska 99508 USA 907-786-7000 gs-ak_asc_datamanagers@usgs.gov The original data are stored as a Microsoft Access database in a Windows operating environment. Data are exported as comma separated text files (.csv) for dissemination. Leach, C.B. Weitzman, B.P. Bodkin, J.L. Esler, D. Esslinger, G.G. Kloecker, K.A. Monson, D.H. Womble, J.N. Hooten, M.B. 2024 journal article Ecosphere 15(12):e70084 online Ecological Society of America Leach, C.B., Weitzman, B.P., Bodkin, J.L., Esler, D., Esslinger, G.G., Kloecker, K.A., Monson, D.H., Womble, J.N., Hooten, M.B., 2024. The dynamics of sea otter prey selection under population growth and expansion. Ecosphere 15(12):e70084. https://doi.org/10.1002/ecs2.70084 https://doi.org/10.1002/ecs2.70084 The number of prey items per dive is more accurate for larger items (e.g., octopus compared to mussels). Finally, size class of prey items is based on visual comparison of item to the width of the otter's paw (average in Alaska is 52 millimeters). We complete lengthy quality assurance-quality control (QAQC) procedures for foraging data. Rows are checked against field data sheets for missing values, outliers, and inconsistencies. Prey codes and uniqueness of bout identifiers are verified. Observer and otter locations are plotted and checked for validity. Due to the observational nature of collecting foraging data, there will always be missing data. Some fields are not relevant to deriving meaning, e.g., observer, or can be assigned, e.g., unique bout identifier. Other fields are more critical to analyses and users must decide how to treat missing data before conducting analyses. This data set has been checked, however, where missing data could be assigned, it was completed. Focal otter foraging locations are based on estimated distance and angle from observers and features marked on GPS base maps (e.g., emergent rocks, easily distinguished points on islands) and therefore should be considered accurate within 100 meters. FIELD: Experienced personnel observed tagged or untagged foraging sea otters from terrestrial vantage points throughout the study regions. Using 10x42 binoculars, Questar Field Model 53x89 spotting scopes and stopwatches, the observers followed single "focal" sea otters through successive dives, collectively referred to as a bout. They recorded the apparent sex and age class of the focal otter, the start and end time of observations, sea otter dive times, surface intervals, foraging success and the type, number and size of prey items, with size quantified relative to the focal otter's paw width. Handling time for prey consumption and portion lost, stolen, or given to a pup was also recorded. Focal otter locations were obtained by moving the map panning arrow on the handheld GPS to the focal otter's location and recording the coordinates. Locations for pre-GPS foraging bouts were estimated by using marine charts. Time of day was obtained from the GPS or observer's/recorder's watch. Dive times and surface times were obtained from the stopwatch. Raw data were recorded on data sheets by the observer or a data recorder while in the field and transcribed to an electronic format after returning from the field. Unknown DIGITIZATION: Prior to 2014, field data were entered into Microsoft Excel spreadsheets from paper data sheets and then imported into a Microsoft Access database. After 2014, raw field data were entered directly into a Microsoft Access database from paper data sheets after the field season. Raw field data were entered into Microsoft Access database using a data entry form with built in validations. Access data were exported as the csv file described here. Unknown LITERATURE CITED: Bodkin, J.L., 2011. SOP for collecting sea otter forage data, v. 3.2, Southwest Alaska Inventory and Monitoring Network. Natural Resource Report NPS/SWAN/NRR—2011/394. National Park Service, Fort Collins, Colorado. https://irma.nps.gov/DataStore/DownloadFile/428470 Gorbics, C.S., Bodkin, J.L., 2001. Stock structure of sea otters (Enhydra lutris kenyoni) in Alaska. Marine Mammal Science 17(3):632-647. https://doi.org/10.1111/j.1748-7692.2001.tb01009.x Unknown Regions and areas in this data set are described without coordinates, e.g., Southeast Alaska, Glacier Bay National Park and Preserve. Sites are described with site names and refer to a general location. Sites are typically assigned based on focal otter coordinates or observer coordinates if no otter coordinates were recorded. In some cases, site names were recorded but not otter or observer coordinates. Focal otter locations are described either with location names, e.g., Sita Reef, and/or coordinates. Point 0.00000001 0.00000001 Decimal degrees World Geodetic System of 1984 World Geodetic System of 1984 6378137 298.257223563 GLBA_SEOT_forage_taxonomy_1993-2019.csv Table providing species codes, names, and the taxonomic classification of all observed sea otter prey items in this data package. Presented in a Comma Separated Value (CSV) formatted table. Author defined preytype_cd Three-letter species code used during the sea otter foraging study. In most instances, a concatenation of the first two letters of the Genus and first letter of the species. Author defined Three-letter species code used during the sea otter foraging study. common_name Common name of the prey species or group of species sampled. Author defined Common name of the prey species or group of species sampled. phylum Identity of prey items at the Phylum level. Blank cells indicate that the taxa is unspecified. Integrated Taxonomic Information System (ITIS) or World Register of Marine Species (WoRMS) Identity of prey items at the Phylum level. class Identity of prey items at the Class level. Blank cells indicate that the taxa is unspecified or the Class is unknown. Integrated Taxonomic Information System (ITIS) or World Register of Marine Species (WoRMS) Identity of prey items at the Class level. order Identity of prey items at the Order level. Blank cells indicate that the taxa is unspecified or the Order is unknown. Integrated Taxonomic Information System (ITIS) or World Register of Marine Species (WoRMS) Taxonomic identification of prey at the Order level. family Identity of prey items at the Family level. Blank cells indicate that the taxa is unspecified or the Family is unknown. Integrated Taxonomic Information System (ITIS) or World Register of Marine Species (WoRMS) Taxonomic identification of prey at the Family level. genus Identity of prey items at the Genus level. Blank cells indicate that the taxa is unspecified or the Genus is unknown. Integrated Taxonomic Information System (ITIS) or World Register of Marine Species (WoRMS) Taxonomic identification of prey at the species level. scientific_name Identity of prey items at the Species level. Blank cells indicate that the taxa is unspecified or the Species name is unknown. Integrated Taxonomic Information System (ITIS) or World Register of Marine Species (WoRMS) Identity of prey items at the Species level. ITIS_TSN A Taxonomic Serial Number (TSN) is a unique, persistent, non-intelligent identifier for taxa in the context of the Integrated Taxonomic Information System (ITIS). Blank cells indicate that the taxa is not present in the ITIS database. Integrated Taxonomic Information System (ITIS) Integrated Taxonomic Information System Taxonomic Serial Number. AphiaID AphiaID is a unique and stable identifier for each available taxa in the World Register of Marine Species (WoRMS) database. Blank cells indicate that the taxa is not present in the WoRMS database. World Register of Marine Species (WoRMS) AphiaID is a unique and stable identifier for each available taxa in the World Register of Marine Species (WoRMS) database. notes Notes regarding prey taxonomy such as Scientific name changes. Author defined Notes on prey taxonomic changes. GLBA_SEOT_forage_bouts_1993-2019.csv Table with year-specific information on focal sea otter foraging behavior observations and prey selection in Glacier Bay National Park and Preserve. Each record (row) represents one prey item or in the case of an unsuccessful dive, no prey items- retrieved by foraging sea otters. The unit of analyses is the unique bout which is comprised of one or more dives and each dive is comprised of one or more rows of prey retrieved. Each record also holds additional information about the focal otter, bout, dive, and/or prey item. Presented in a Comma Separated Value (CSV) formatted table. Author Defined bout_id Unique identifier of each sea otter foraging bout. Unique identifier 1 is assigned to the first observed bout. The next foraging bout, whether the same otter or a different otter receives unique identifier 2, etc. The bout identifier changes every time there is a break in the dive sequence. Observers identify unique bouts on their field data sheets, then data entry should ensure unique bout number within file. This data set contains various bout identification schemes have been used in the original spreadsheets and transferred to the compilation. Author defined Bout identifiers are unique to each actual bout. Typically, they are comprised of a concatenation of bout date, observer initials, and a sequential number for the observer for the day. study_cd Unique identifier for the study. Sea otter foraging data is collected for a variety of studies at different locations. Author defined GLB Glacier Bay (approximately 58.8946N, 136.8195W) before-after-control-impact study. Impact refers to sea otters, control refers to areas without sea otters or areas with a short timeline of sea otter presence. This study code is used for all sea otter foraging data collected in Glacier Bay National Park. Author defined bout_date Date observations were made in the field, formatted as YYYYMMDD. Author defined 19930417 20190424 Date (YYYYMMDD) start_time Time of day (Alaska time) that observers began collecting foraging data for the recorded bout. Blank cells indicate that no data was collected. Author defined 06:40 21:12 hh:mm (24-hr) end_time Time of day (Alaska time) that the observer finished collecting foraging data for the recorded bout. Blank cells indicate that no data was collected. Author defined 6:58 21:21 hh:mm (24-hr) obs_lat Latitude of the observer at the time of data collection during a bout. Blank cells indicate that no data was collected. Author defined 58.37545875 59.06636 decimal degrees obs_long Longitude of the observer at the time of data collection during a bout. Blank cells indicate that no data was collected. Author defined -136.77757 -135.56727222 decimal degrees otter_lat Focal sea otter latitude for the bout, may be different for each dive (see 'dive_otter_lat') but often is one location for an entire bout. Blank cells indicate that no data was collected. Author defined 58.122833 59.06584 decimal degrees otter_long Focal sea otter longitude for the bout, may be different for each dive (see 'dive_otter_long') but often is one location for an entire bout. Blank cells indicate that no data was collected. Author defined -136.77783 -135.009906 decimal degrees sex_cd Sex code of focal sea otter observed during the foraging bout. Author defined u Unknown sex or sex not recorded. Author defined f Female sea otter Author defined m Male sea otter Author defined ageclass_cd Field estimate of age class of focal sea otter. Author defined u Unknown age-class or age-class not recorded. Author defined a Adult, approximately 3-10 year old sea otter based on size, grizzle, behavior. Author defined o Aged Adult, geriatric sea otter, approximately older than 10 years based on appearance. Author defined j Juvenile sea otter, older than a weanling or pup, but not yet subadult, approximately 6 months to 1 year based on appearance and behavior. Author defined s Subadult, independent sea otter, but not yet full grown or having full adult abilities. Author defined p Pup sea otter, still dependent and with mother. This age designation is only used if the pup is the focal otter that feeding observations are being collected on. Approximately less than 8 months based on appearance and behavior. Author defined pupsize_cd A code indicating if the focal sea otter had a pup and if so, what was the general size of the pup? Blank cells indicate that no data was collected or for unknown sex, male otters, or females too young to bear pups. The code "u" is only used if the pup status of an adult female is unknown. Author defined u Unknown, undetermined, or not recorded for adult, female focal sea otter. author defined y Yes, focal female sea otter does have a dependent pup but the age of the pup was not determined or recorded. author defined n No, focal female sea otter does not have a dependent pup. author defined l Focal sea otter has a large pup. Pup size based on visual appearance and behaviors. Author defined m Focal sea otter has a medium size pup. Pup size estimate based on visual appearance and behavior. Author defined s Focal sea otter has a small pup. Pup size estimate based on visual observations and behaviors. Author defined d Focal sea otter has a dead pup. Author defined territorial_male_flg Flag indicating if male focal sea otter is a territorial male or not. Not territorial also includes unknown territorial status. This is not easy to determine in unmarked otters, but can sometimes be deduced by the otter's behavior patterns, such as patrolling, dominance over other males, consorting with females, and checking on all the otters in the area. Blank cells indicate that the sea otter was identified as female or unknown sex. Author defined 0 Not a territorial male or unknown status Author defined 1 Territorial male Author defined region_cd Largest spatial category for sea otter foraging data. Gorbics and Bodkin 2001 SEA Southeast Alaska Gorbics and Bodkin 2001 area_cd A smaller geographic designation than region for sea otter foraging data. Author defined GLBA Glacier Bay National Park and Preserve (approximately 58.8902N, 136.8186W). Author defined SICY Waters of Icy Strait, south of the main entrance to Glacier Bay National Park and Preserve (approximately 58.2733N, 135.6507W). Author defined site_name Smallest designated spatial scale. In 2019, authors divided Glacier Bay into broad sites and categorized each sea otter foraging bout. See 'GLBA_SEOT_forageSites_lumped2024.jpg' provided with this data release package. Author defined Adams Adams Inlet (approximately 58.8806N, 135.9387W) in GLBA area. Author defined Bartlett Bartlett Cove vicinity (approximately 58.4533N, 135.9203W) in GLBA area. Author defined Berg Berg Bay (approximately 58.5165N, 136.1704W) in GLBA area. Author defined Boulder Boulder Island and Reef vicinity (approximately 58.5686N, 135.9952W) in GLBA area. Author defined Caroline/Garforth Caroline Shoal and Garforth Island vicinity (approximately 58.7739N, 136.1065W) in GLBA area. Author defined Carolus Point Carolus vicinity (approximately 58.3639N, 136.0529W) in GLBA area although some sea otter locations may technically be beyond the border of Glacier Bay National Park and preserve. Author defined Drake/Francis Drake and Francis Islands vicinity (approximately 58.6575N, 136.2565W) in GLBA area. Author defined Dundas Dundas Bay (approximately 58.3462N, 136.3417W) in GLBA area. Author defined Fingers Fingers Bay (approximately 58.5785N, 136.1985W) in GLBA area. Author defined Flapjack Flapjack reef vicinity (approximately 58.6153N, 136.0202W) in GLBA area. Author defined Geikie Geikie Inlet (approximately 58.6155N, 136.4638W) in GLBA area. Author defined Gustavus Point Gustavus vicinity (approximately 58.3809N, 135.9216W) in GLBA area, although some otter locations may technically be beyond the border of Glacier Bay National Park and preserve. Author defined Inner Beardslee Eastern portion of the Beardslee Island vicinity (approximately 58.5334N, 135.8666W) in GLBA area. Author defined Leland Leland Island (approximately 58.6499N, 135.9834W) in GLBA area. Author defined Marbles North and south Marble Islands (approximately 58.6567N, 136.0565W) in GLBA area. Author defined Muir Muir Inlet (approximately 59.0587N, 136.2862W) in GLBA area. Author defined Outer Beardslee Western portion of the Beardslee Island vicinity (approximately 58.5174N, 135.9486W) in GLBA area. Author defined Rush/Ripple Along the western shore of the lower bay, in the vicinity of Rush Point and Ripple Cove (approximately 58.4722N, 136.0780W) in GLBA area. Author defined Russel/Reid Russel Island and Reid Inlet vicinity (approximately 58.8935N, 136.7686W) in GLBA area. Author defined Sandy/Sturgess Sandy Cove and Sturgess Island vicinity (approximately 58.7082N, 136.0211W) in GLBA area. Author defined Scidmore/Hugh Miller Scidmore Bay and Hugh Miller Charpentier Inlets (approximately 58.7653N, 136.5710W) in GLBA area. Author defined Sita/Strawberry Sita reef and Strawberry Island vicinity (approximately 58.5209N, 136.0221W) in GLBA area. Author defined Willoughby Willoughby Island vicinity (approximately 58.6058N, 136.1533W) in GLBA area. Author defined Althorp Waters, islands, and islets in Port Althorp (approximately 58.1488N, 136.3391W) in the SICY area. Author defined Inian Inian Islands vicinity (approximately 58.2439N, 136.3476W) in SICY area. Author defined Idaho Waters, islands, and islets in Idaho Inlet (approximately 58.1702N, 136.2206W) in the SICY area. Author defined specific_location_txt The smallest spatial scale at which foraging data are defined. Author defined The smallest spatial scale at which foraging data are defined. The list of specific locations will vary by observer. It is recommended to use latitude and longitude or region/area/site for grouping in analyses rather than this field. visibility_cd Code for visibility, in this data a term for the observer's confidence in their observations. The term is a subjective, bout specific, assessment of items that affect an observer's ability to collect foraging data: distance of focal otter, elevation of observer, precipitation, surf/surge/chop, is the otter surfacing in kelp or amongst wash rocks, light level and quality, and any other conditions that are impacting the data collection effort. Author defined un Unknown or unrecorded visibility Author defined ex Excellent visibility Author defined vg Very good visibility Author defined go Good visibility Author defined fa Fair visibility Author defined po Poor visibility Author defined bout_comment_txt Text field containing comments about the foraging bout. Blank cells indicate that no comments were recorded. Author defined Many notes are made here but most common are reasons for ending a bout, information about the focal otter or location. dive_otter_lat Focal sea otter latitude for the dive, which may be different for each dive but often is one location for an entire bout (see 'otter_lat'). Blank cells indicate that no data was collected. Author defined 58.159317 59.06584 decimal degrees dive_otter_long Focal sea otter longitude for the dive, which may be different for each dive but often is one location for an entire bout (see 'otter_long'). Blank cells indicate that no data was collected. Author defined -136.99945 -135.8625 decimal degrees dive_num Sequential integer number assigned to each dive within a bout. Each bout begins with its own dive number 1. The current protocol calls for recording 20 dives within each bout but often the bout ends early because the focal otter leaves the vicinity, finishes feeding or is interrupted by another animal. Bouts may have more than 20 dives because some foraging protocols recommend watching all dives. Author defined 1 66 integer dive_time Time in seconds spent by focal sea otter searching for or retrieving prey, underwater or off emergent rocks or in kelp canopy. Dive time is recorded even if no prey is retrieved. Blank cells indicate that no data was collected. Author defined 1 335 seconds surface_time Surface time, time in seconds that focal otter spends on surface, including time spent handling prey, consuming prey, grooming, interacting with other non-focal otters, moving locations, etc. Surface times in excess of 600 seconds, if not directly associated with feeding, generate the end of the bout. Blank cells indicate that no data was collected. author defined 1 962 seconds success_cd A code indicating if a sea otter successfully retrieved prey after a dive. In some other foraging data sets this is called 'dive outcome'. Author defined u Unknown, undetermined, or unrecorded dive outcome. Author defined y Yes, successful retrieval of prey. Author defined n No, not successful prey retrieval. Author defined c Carryover, a prey item that was dropped or partially consumed was re-retrieved. Author defined t Travel, observer decides dive was a travel dive not a foraging dive. Author defined x Non-feeding dive, observer decides dive was not a feeding dive. This often occurs when a focal otter is interrupted by another otter. Author defined i Non-feeding dive, focal otter is interacting with another otter. Author defined dive_comment_txt Any comments the observer feels are relevant to the specific dive. There are other comment fields for the bout and individual prey items. Blank cells indicate that no comments were recorded. Author defined Any comments the observer feels are relevant to the specific dive. preytype_cd Three-letter code for prey item retrieved on successful or carry over dives. Blank cells indicate that all dives that are not foraging dives (travel, unknown, interacting, evasive) or are unsuccessful or unknown success. All successful foraging and carryover dives should have a prey code, including "uni" for unidentified prey. Author defined Three-letter code for prey item retrieved on successful or carry over dives. See table 'GLBA_SEOT_forage_preyTaxonomy.csv' included with this data release for a list of all prey species type codes. prey_qty Number of each prey item retrieved by the sea otter. Blank cells indicate that no data was recorded, it was a non-foraging dive, or the dive was unsuccessful. Author defined 1 135 count preysize_cd Estimated size, relative to otter paw width, of each prey item. Analysis steps translate the size code to actual millimeters based on averages of paw measurements of captured otters. See 'GLBA_SEOT_preySizeCode.jpg' for a visual explanation of size codes. Blank cells indicate no data for non-foraging or unsuccessful dives. Bodkin 2011 1a Prey less than or equal to one-third of the paw width of the focal otter. Author defined 1b Prey larger than one-third paw width but smaller than the larger third of the paw. Author defined 1c Prey that is larger than two-thirds of the paw width of the focal otter, but less than or equal to one full paw width. Author defined 2a Prey larger than one full paw width but less than or equal to one and one-third of the paw width of the focal otter. Author defined 2b Prey larger than one and one-third paw width but smaller than the larger one and a third of the paw width. Author defined 2c Prey that is larger than one and two-thirds of the paw width of the focal otter, but less than or equal to two full paw widths. Author defined 3a Prey larger than two full paw widths but less than or equal to two and one-third of the paw width of the focal otter. Author defined 3b Prey larger than two and one-third paw widths but smaller than the two and two-thirds of the paw width. Author defined 3c Prey that is larger than two and two-thirds of the paw width of the focal otter, but less than or equal to three full paw widths. Author defined 4z Prey larger than three paw widths of the focal otter; observer should try to estimate prey size in centimeters if possible. Author defined 9z Unknown prey size Author defined 1z Prey is smaller than 1 paw width but observer could not distinguish further. Also used for data from older studies when a, b, c categories were not in use. Author defined 2z Prey is smaller than 2 paw widths but observer could not distinguish further. Also used for data from older studies when a, b, c categories were not in use. Author defined 3z Prey is smaller than 3 paw widths but observer could not distinguish further. Also used for data from older studies when a, b, c categories were not in use. Author defined prey_size_cm For large prey items, observers may choose to estimate the overall largest size in centimeters of the item. 'Prey_size_cd' should be blank if 'pre_size_cm' is used. Author defined 14 155 centimeter not_eaten_pct Proportion of prey not consumed by the focal sea otter. Blank cells indicate no data for non-foraging or unsuccessful dives. Author defined 0.02 1.0 decimal fraction not_eaten_reason_cd A description of why the prey wasn't consumed by the focal sea otter. Blank cells indicate that no data was recorded or all the prey was consumed. Author defined p Prey provided to pup, prey not consumed by the focal otter was given to or taken by the focal otter's pup. Author defined s Stolen, the prey not consumed by the focal otter was stolen by another otter that is not the pup of the focal otter Author defined d Dropped, prey not consumed by the focal otter that is dropped rather than stolen or given away Author defined u Unknown reason why an otter did not fully consume a prey item. Author defined handling_time Handling time, the amount of time in seconds that the focal sea otter uses to manipulate and consume each prey item. Usually equal to surface time unless the otter spends more than 10 seconds grooming or engaging in activity other than prey handling and consumption. 'Handling_time' is set to a blank cell unless the observer records a specific handling time on the field data sheet. Author defined 2 510 seconds prey_comment_txt Observer comments about a specific prey item. Blank cells indicate that no comments were recorded. author defined Observer comments about a specific prey item. GLBA_SEOT_preySizeCode.jpg Graphic showing the size of sea otter prey in relation to the average sea otter paw size. Author Defined GLBA_SEOT_forageSites.jpg Graphic showing the location of sea otter foraging bout observations from 1993-2019. Sites located in Icy Strait are not shown on the graphic. 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 Tabular data in CSV format; FGDC metadata in XML and HTML formats. https://doi.org/10.5066/P9T6UB5G None 20241205 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