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Tool-use frequency by individual sea otters in California


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Tinker, M.T., 2017, Tool-use frequency by individual sea otters in California: U.S. Geological Survey data release,


Sea otters are well-known tool users, employing objects such as rocks or shells to break open invertebrate prey. We used a series of generalized linear mixed effect models (GLMEs) to examine observational data on prey capture and tool use from 211 tagged individuals from five geographically defined study areas throughout the sea otter’s range in California. Our best supported model was able to explain 75% of the variation in the frequency of tool-use by individual sea otters with only ecological and demographic variables. In one study area, where sea otter food resources were abundant, all individuals had similar diets focusing on preferred prey items and used tools at low to moderate frequencies (4-38% of prey captures). In the remaining [...]


Point of Contact :
M. Tim Tinker
Originator :
M. Tim Tinker
Metadata Contact :
William M Perry
Publisher :
U.S. Geological Survey, Western Ecological Research Center
Distributor :
U.S. Geological Survey - ScienceBase
USGS Mission Area :
SDC Data Owner :
Western Ecological Research Center

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sea otter using a tool with a clam .jpg thumbnail 100.22 KB
Tool use frequency by individual sea otters in California.csv 124.85 KB


All data were collected as part of population studies led by the U.S. Geological Survey, in collaboration with the Monterey Bay Aquarium, UC Santa Cruz and California Dept. of Fish and Wildlife, with the overall goal of understanding factors affecting population recovery. Separate research studies were conducted under this broader umbrella research program, whose goals were often more specific (e.g. understanding the impacts of specific stressors in particular areas of the sea otters range). By tagging and monitoring individual sea otters over multiple years, the researchers were able to identify individual foraging preferences and tool-use behavior.


The authors of these data require that data users contact them regarding intended use and to assist with understanding limitations and interpretation. 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 (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, 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.
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  • USGS Western Ecological Research Center



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DOI doi:10.5066/F78050S9

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