Trumpeter Swans on Kirner Pond at dawn - Photo: Bob Phreaner
Late Autumn 2020 Update
by Laura Davis and Liam Antrim
Hats off to all of our volunteers! With both experienced volunteers and new recruits – thirty strong – we survey foraging fields weekly, plus study overnight usage at roosting sites. Foraging surveys started the last week of October with two Trumpeter Swans counted. As of November 25, we have ramped up to 163 Trumpeter swans; roughly 15% are juveniles. We have, in addition, a single juvenile Tundra swan. At this time of the year, the swans are attracted mostly to remnant kernels of corn in harvested fields.
Starting its third year now, our OPAS roosting study is motivated by the team's interest in identifying locations and habitats used overnight by adult swans and families with juveniles – tracking any changes in usage over time. We accumulate these data in a consistent manner, but continue to assess and keep the efforts of this special study meaningful as well as sustainable over time for our volunteers. Freshwater habitats used for roosting by swans are not abundant in our area and some features of roosting sites can present real or perceived hazards to the swans. When collisions with powerlines are observed, we record the conditions that may trigger the impact and consult with WDFW on mitigations.
Dawn on Kirner Pond - Photo: Bob Phreaner
This year, “site monitors” have been recruited to watch nearby wetlands for overnight swan use. They keep daily notes on numbers and timing of arrivals and departures. These neighbors add another dimension and additional value to this OPAS citizen-science project.
In preparation for this survey season, we spoke with Martha Jordan of the Northwest Swan Conservation Association (NWSCA) and Kyle Spragens, the Wildlife Section Manager at WDFW. WDFW is currently using last season's OPAS swan data to test integration of Trumpeter Swans with a database that supports analysis of wildlife population trends over time: the Wildlife Survey and Data Management (WSDM) database. This is typically used for species of special concern (e.g. endangered or threatened) or species that are hunted in Washington State; the swans are neither. Previously, our data was integrated only into WDFW's Priority Habitats and Species (PHS) database, which is used primarily as a planning tool for local communities to identify habitat types and species distributions.
Trumpeter Swan - Photo: Dee Renee Ericks
Although the population of winter swan residents here is not as high as in counties north of Seattle, WDFW sees the OPAS swan surveys as an outstanding example of Citizen Science work generating quality data. Currently, OPAS is the only non-governmental team in the Pacific Northwest conducting regular swan surveys and generating data of sufficient quality for agency databases.
Our swan team also expects to contribute this year to the state-wide, mid-winter swan census that is conducted every five years. This winter’s data will be especially important for population trend analysis because the summer breeding ground census of swans is no longer supported by the Canadian government.