With funding support from the Grant County Public Utility District of Washington State (Grant PUD) and Oregon State University (OSU), this Caspian tern tracking project is one of many collaborative efforts between researchers with OSU, the US Geological Service – Oregon Cooperative Fish and Wildlife Research Unit, and Real Time Research, Inc., which is collectively known as Bird Research Northwest (BRNW). This partnership began in 1997 to investigate the impacts of avian predation on juvenile salmonids in the Columbia River Basin.
We are using 12 gram, solar-powered ARGOS satellite telemetry tags, manufactured by Microwave Telemetry Inc., to track adult Caspian terns during their breeding season and opportunistically throughout the rest of the annual cycle. These tags have an expected life span of one or more years, and are allowing us to explore not only the activity of terns within the Columbia Basin (the specific management interest), but also tern migration and wintering patterns in the Pacific Flyway region. We deployed 28 of these tags on terns captured at Goose Island in Potholes Reservoir near Othello, Washington in April of 2014. The following year, we deployed an additional 18 tags on terns captured at Goose Island, and 28 tags on terns captured at Crescent Island in the McNary Pool of the Columbia River, near the Tri-cities area of Washington.
The satellite tags are programmed to collect data on a 32 hour duty cycle, with 6 hours on and 26 hours off. This duty cycle allows us to collect locations during both daylight and nighttime periods, providing information on foraging, roosting, and potential nesting sites. The accuracy of the locations ranges from ≤ 150 m to over 1000 m, depending on satellite positioning and atmospheric conditions.
Along with satellite tags, we also used plastic leg bands with engraved “field readable” alphanumeric codes to individually mark the Caspian terns prior to their release. These bands will stay on longer than the satellite tags, and allow us to identify the birds even after the tags have fallen off. We have been banding Caspian terns with these field readable bands in Oregon, Washington, and California since 2005, and have banded about 6400 individuals. If you see one of our leg banded Caspian terns you can report them and help us keep track of their movements. Just click here or on the “Have you seen me?” icon to the right to go to our band reporting site. Banded birds can also be directly reported to the Bird Banding Laboratory.