Trumpeter Swans - Photo: John Gussman

Autumn 2022 Update

This Conservation Matters column is from the November - December 2022 Harlequin Happenings newsletter.

by Laura Davis and Liam Antrim

It's mid-autumn migration for birds – time to attune our ears and glimpse upwards then around the bend in the road, following the sounds and the line of trees into the field. The Trumpeter Swans, encouraged by nighttime freezes in the boreal forests of Alaska, are flying toward us – guided by their previous seasons' successes here. The Trumpeters won’t travel further south than needed, and we are at the southern edge of their core winter range. And in the end, it will be the healthy pairs returning to the breeding grounds that will win the survival contest. That means not going any further south than necessary. Last year, the swans had arrived in three distinct migrational waves by mid-winter.

After their long journey, the swans look for carbohydrates and fats to replenish reserves and then continue to sustain them through the worst of winter. Every acre of forage is not nutritionally equivalent and they look for sites that meet their caloric needs efficiently. Efficiency is fundamental for these large, flying birds. Even local movement from foraging to roosting grounds burns a lot of calories.

We have pairs of roosting and foraging sites that foster regular patterns of daily back and forth. Commutes typically occur shortly after sunrise, and then, well after sunset. The latter is a challenging time for many of us at the darkest time of year. So too with the swans who in unfamiliar places or conditions run a risk of collisions with power lines. Throughout the season there is reason to adjust foraging and roosting locations due to food and water availability, windy or icy weather, feelings of safety or harassment: what circuit of sites will least exhaust their energy resources? The swans need enough water and grit to process their diet – both day and night, even if that means a lesser quality food. Permanent water is also essential to nighttime safety. Making adjustments throughout the season, the life of a swan isn't so predictable.

In other areas of their range, the swans might hop over to their roosting sites for a midday drink; thus far, our studies have not seen that activity here. In our area, swans may find low areas where puddles of dew or drizzle accumulate and contribute fluids to their midday grazing. Learning about swan behavior in other ares helps us be alert to and observant of additional behavioral clues.

Adult Trumpeter Swans find pools of water in pasture grasses along Schmuck Road. *Photo: John Gussman*

Our study is dynamic and observations lead to more questions. With over a decade of surveys, our OPAS swan team continues to ride the momentum of our amazing volunteers' efforts. We invite you to learn more. Attend the OPAS members' meeting on November 16 where you will hear and see illustrated our insights into the swans' use of our area, see the population changes from year-by-year, and the usages of different food stuffs and sites through the year. See, too, our OPAS Swan Study webpage for our report and details on the 2021–22 season.

You may find that joining our team is the most engaging way to learn about the swans and the habitats that our agricultural landscapes provide. Please contact OPAS if you're interested. We survey weekly at midday for the five months the swans are here. In addition, once a month, some of our volunteers are out before dawn for a simultaneous count at the roosting sites. The more volunteers we have for our dawn surveys, the more we can learn.