Trumpeter Swans - Photo: Wendy Feltham
2023–2024 Season Summary
OPAS Swan Team's 2023–2024 data-analysis graphics here
by Liam Antrim and Laura Davis
While our 2023–24 monitoring of overwintering swans in the lower Dungeness Valley followed the patterns of a typical season, strong differences in the weather made that winter unique. Through thirteen years of this study led by OPAS volunteers, we have learned that there is no typical year. On October 24, we appreciated a stunningly successful Trumpeter Swan family with six juveniles who had arrived early and targeted the Kirner Pond roosting site north of Woodcock Road. Across the area the next morning we witnessed many waterfowl overhead and flying southeast in strong winds, including nearly 100 Tundra and Trumpeter Swans. Their autumn migration had reached our area, and some Trumpeters stopped to overwinter with us. Swans remained in our area through early April – a 169-day winter season.
Two groups of Trumpeter Swans on Kirner Pond, October 2023, the family with six juveniles in the foreground. Photo: Bob Phreaner
El Niño was expected for the winter months and, as forecasted, produced temperatures warmer than normal throughout fall and early winter. According to Washington Department of Fish and Wildlife's (WDFW) Kyle Spragens, warmer conditions allowed Trumpeter Swans to overwinter further inland and north than usual as freshwater habitats remained ice free and accessible. Swan distribution was less compressed, and fewer swans reached our coastal location.
A major weather anomaly for this winter was the severe cold snap and snow that broke through the El Niño weather in mid-January 2024. Subfreezing temperatures lasted about three days, yet ice persisted for a couple of weeks on ponds and wetlands (Kirner Pond/Gaskell Slough, a pond in Happy Valley, Cat Lake and the Gierin Marsh at Graysmarsh Farm) affecting roosting, foraging and freshwater supply for swans in the lower Dungeness area. The regional extent and severity of the freezing conditions tested the swans' resilience and certainly concerned us. However, swan-team members found them on saltwater bays, primarily in Dungeness Bay (high count of 61), but also Washington Harbor and off Jamestown Beach. After landscapes thawed out, approximately the same number of swans remained in our area and returned to the freshwater roosting locations.
Figure 1: Numbers of Swans Counted during Midday Surveys, 2023–24
All tallied, our seasonal average of 56 swans observed foraging at midday weekly was 40% of the average of 143 swans from the previous five winters (Figure 2). Our high foraging count for the winter was 89 swans. The majority of swans left us between March 13 and 19, with only a few swans lingering east of the Sequim-Valley airport on pasture and green, winter-planted grain.
Figure 2: Thirteen Seasons of Swan-Foraging Counts, 2011–2024
Numbers of migratory swans were low this past winter throughout northwest Washington and lower here than we'd ever seen. WDFW, Northwest Swan Conservation Association, and partners conduct a single annual mid-January survey count after the lengthy period of fall migration, when the overwintering swans populations are most stable. For 2024, their count of approximately 7,700 Trumpeter Swans (TRUS) in the survey area was 60% of the average for the preceding four years. WDFW considers that low regional swan counts these past two years, 2022–24, compared with 2016–22, were likely influenced by a combination of factors including poor warm-season nesting conditions, expanded wintertime distribution, HPAI (highly pathogenic avian influenza) and the unusual weather conditions from breeding to overwintering grounds experienced by the TRUS Pacific Coast Population.
During the two coldest weeks of January, we assisted with WDFW's mid-winter survey and broadened the extent of our surveys east to Chimacum Creek in Jefferson County and west to the Wa'atch River near Neah Bay. While we counted 76 Trumpeter Swans in the lower Dungeness, 90 Trumpeters and one Tundra Swan foraged on rain-flooded pasture adjacent to Chimacum Creek where, during this icy spell, it was warmer than the lower Dungeness by five degrees Fahrenheit. This is our first known record of a higher count of swans on that valley's watery agricultural landscape than in our rain-shadow location. Two adult TRUS were seen both weeks at the Wa'atch River west of Neah Bay.
Amidst the snow and ice, Trumpeter Swans found water and pasture for forage in the Chimacum Creek drainage at Short's Farm. Photo: Wendy Feltham
Habitat and Adjacency – Through our six years of studies of both foraging and roosting locations used by swans, it has become increasingly clear that swans adjust their usage to minimize the energy expended flying between their day and night-time locations. In mid-January when Kirner Pond was frozen and unavailable for roosting, swans also stopped foraging efforts on nearby fields. When swans roosted on Dungeness Bay, we saw them heading to daytime forage on a fallow carrot field at the nearby Clapp Farm. Swans roosting at Gierin Marsh were tracked to a field just north of the marsh or immediately east to the Mid-Valley Farm on Sequim-Dungeness Way. Similarly, we followed swans foraging in Agnew to nearby roosting at Solmar Lake.
Foraging – Both well-managed grass pastures and harvested corn fields with actively growing winter-grain cover crop are what swans found and chose for forage in the lower Dungeness area. Figure 3 presents swan foraging preferences summarized over the entire winter season and Figure 4, below, shows how forage preferences changed over the course of the winter.
Figure 3: Observed Swan Habitat Usage during Midday Surveys, 2023–24
From late October through early January, most swans were foraging east of the Dungeness River on harvested corn fields and pasture grasses. Throughout the area, harvested corn fields turned green with over-planted winter grain and attracted foraging swans by mid-December. By January, swan foraging shifted westward and swans were distributed across both sides of the river – their focus remaining on fields of pasture grass and the winter grain growth on harvested corn fields.
Figure 4: Week-by-week Observed Swan Habitat Usage during Midday Surveys, 2023–24
A significant change from past years was that very few swans were seen on fields adjacent to Schmuck Road and Port Williams Road; swans were there only during the last two weeks of January. It seems unlikely that forage was inadequate as fields with pasture and corn/winter cover crop were available in this area. Another curious location use occurred in March, when swans were seen for the first time on an irrigation pond adjacent to Spath Road; we spotted swans repeatedly flying there during the day from foraging fields east of the airport though they never stayed on the pond for night roosting. We suspect it offered a valued nearby daytime source of the drinking water needed for digestion.
Farming practices – On January 8 we became concerned for foraging swans after we noticed herbicide had been applied to the portion of pasture southeast of Towne and Woodcock roads. This field had hosted the majority of foraging swans in December. Swans were periodically seen here as plants turned orange and died. Over time, the number of swans foraging on this treated pasture decreased, with the last sighting of two Trumpeters on January 23.
Just west of Towne and Woodcock roads, a short distance further from Kirner Pond, farmers planted a new carrot field on the recently conserved “No-Goat Farm”. We monitored this field for swan usage out of concern that swans would discover and consume the crop or strike the power lines above both roads. When mid-January sub-freezing temperatures were forecasted the farmer shielded the crop with fabric row covers to both protect from the potential damage of freezing conditions and swans. Fortunately for the farmer and we human consumers, no swans were ever seen near the carrots, even with some roots exposed and visible.
During the first two surveys of February, we spotted swans on Graysmarsh-owned fields east of Wilcox Lane. Pulling at a patch of tall Brussels sprouts adjacent to a grain and winter wheat field, the swans did move on and we never heard of any crop damage.
Trumpeter Swans foraging in a Brussels sprouts field were challenging to count due to the topography. Photo: Steve Koehler
Roosting – We gather valuable, detailed roosting data from dedicated volunteers who observe ponds on a more-or-less daily basis at Kirner Pond, near Happy Valley, Three Crabs Road, and between Sequim and Port Angeles. Observations at Kirner Pond often numbered from two to four dozen swans roosting overnight prior to the cold front; relatively few swans returned after waters thawed. In the Happy Valley area, up to 28 swans were roosting in late October to early November, but their numbers dropped by mid-November to only a few swans. At Roberta's Pond at Three Crabs Road, swans were only seen two mornings immediately following the arctic front, plus a single dawn early in spring migration. No swans were observed at the pond between Sequim and Port Angeles this season.
Our teams completed four dawn surveys of all known roosting sites monthly from December to March. In early December, we found most swans roosting on Kirner Pond and adjacent Gaskell Slough. In early January, the usage extended to the Northern Conservation Farm – the waterfowl-hunting ponds west of Olympic Game Farm. With mid-January's cold snap, swans abandoned frozen waters of Kirner Pond for a couple weeks; few returned to Kirner after the ice cleared. A few swans were seen throughout these monthly surveys at Cat Lake. In early February and early March, most swans roosted on Gierin Marsh (Graysmarsh) and Northern Conservation Farm. Immediately after the February roosting survey, seeing swans on Agnew pasture led us to track the swans to our first documentation of swan-roosting at Solmar Lake.
Roosting and foraging swan counts this year varied by 3 to 7 swans within the same week for several reasons, including swans moving or hidden from view and limitations on the area we survey.
Cat Lake was covered in snow and ice and inaccessible to swans in mid-January 2024. We survey this Miller Peninsula roosting site at dawn monthly, but also for the Christmas Bird Count and the mid-winter regional survey. In this photo taken by drone camera, surveyors Steve Koehler and John Gussman are dwarfed near the edge of the lake (foreground, center). Photo: John Gussman
Advocacy – The Port of Port Townsend recently purchased the 253-acre Short’s Family Farm in the Chimacum Creek Valley of Jefferson County and have worked to prepare a farm plan meeting targeted objectives of agricultural land conservation and drainage. Following consultation with Jefferson Audubon, the OPAS swan team submitted comments focusing on the importance of the site's wetland habitats to swans and other migratory waterfowl.
Two Trumpeters on the poorly drained Short's Farm pasture – attractive to migratory waterfowl. Photo: Steve Hampton
Injuries/mortalities – There were three reported swan mortalities in the lower Dungeness Valley this past winter. Highly pathogenic avian influenza (HPAI) was not indicated in any of them, nor were there any known cases in Clallam or Jefferson County. There was, however, an early season outbreak of HPAI in cackling geese on an irrigation pond near Schmuck and Port Williams Roads. Early in the season a Trumpeter died after crashing into a home west of Cat Lake; this swan tested negative for HPAI. In mid-December, a pile of swan feathers was found near Palo Alto Road but too little remained to determine cause of death. Lastly, in late March, an electrocuted TRUS was found under the power lines along Cook Road. A few days after WDFW reported this incident to Clallam PUD, line markers were added to all power lines of concern in the area to mitigate the risk of future collisions.
For further information on the 2023–24 swan season, see our Conservation Matters column from the March–April edition of Harlequin Happenings.