Overwintering bald eagles have long since departed the Squamish River watershed. Many of these migrant birds have dispersed back to their breeding territories, nested, and are now producing the next generation of eagles. The non-breeding population will navigate around new or familiar regions over the course of the summer in pursuit of nature’s countless other bounties. Luckily, we can still enjoy resident bald eagles year-round in Squamish!
Since we counted overwintering bald eagles last January, we’ve been compiling our data to provide you with our end of season results and update.
The 2022/2023 EagleWatch season began on Saturday, November 5th, 2022 and ran until Sunday, January 1st, 2023. The 27th season of EagleWatch was eight weeks and one day in length, 57 days in total, making it the shortest season from the last three years (though by only a few days). EagleWatch continued into the program’s third modified season as a citizen science initiative with the twice-daily eagle count and monitoring schedule that was created in 2020/2021. Daily morning monitoring shifts ran from 10:00 am to 11:00 am, and afternoon shifts ran from 2:00 pm to 3:00 pm. A total of 116 counting shifts were offered this season, and each survey day had at least one shift covered by a dedicated volunteer, so the number of eagles in the region was counted on each and every survey day throughout the entire season.
The highest eagle count of the 2022/2023 EagleWatch season occurred during a morning counting shift on Tuesday, December 8th when 171 bald eagles were counted (109 adults and 62 juveniles). (This was the highest hourly count recorded since December 8, 2012.) The lowest count of the season occurred during a morning counting shift on Thursday, November 17th where a total of 2 bald eagles were counted (2 adults and 0 juveniles). During the 2022/2023 season, there were no shifts producing counts with 0 eagles, or even shifts with only one single eagle being detected. Though there are various reasons for low count numbers throughout the span of a season, weather is usually a major factor.
Annual comparisons can now be made between three seasons of EagleWatch and significant trends can be noticed, especially with more than two data sets. We can further confirm the time period where the highest number of overwintering bald eagles can be viewed in the region, also known as peak viewing season. Peak is considered to be the time period where 30 or more eagles can be observed at a time, and when this number is first and last reached over the season. Two other trends discovered over the years are: more adult eagles are detected than juveniles (typically due to low juvenile survival rates), and more eagles are detected in the morning than in the afternoon (roosting eagles have yet to move around for the day).
Peak Viewing Season
2020-2021 November 15 to December 12
2021-2022 November 6 to November 30
2022-2023 November 16 to January 1
Number of Eagles Detected by Season
2020-2021 1836 eagles
2021-2022 1336 eagles
2022-2023 4098 eagles
The most notable weather event of the EagleWatching season actually occurred before the counting even began. In past EagleWatch seasons, weather events such as atmospheric rivers affected our counts. This year was quite the opposite wherein many areas of southern British Columbia experienced a significant fall drought. During months that would normally see the transition into the rainiest time of the year, many southern regions, including Squamish and Brackendale, were going on nearly three months without any prolonged periods of precipitation. It wasn’t until around October 23rd that the Squamish area received a notable bout of rain.
These dry conditions resulted in lower water levels, creating a complex in some areas throughout the Squamish River watershed where salmon did not have enough water to continue migrating upstream to spawn. This complex even resulted in low salmon returns to the Tenderfoot Creek hatchery, which can be an indicator reflecting other areas of the the Squamish River watershed. Unlike in past EagleWatch citizen science seasons, where too much rain and high water levels washed out the valuable salmon carcasses that the eagles require to feed on, the dry conditions delayed and stalled the salmon altogether. We believe that many were delayed in initiating their migrations or were held up in abundance further downstream within the Brackendale region for the eagles to feed upon, therefore bolstering EagleWatch count numbers from the Eagle Run Dike. The Squamish River is a delicate system: although natural annual fluctuations within the ecosystem are necessary, sudden or extreme changes and events can have both short and long-term effects on the species that inhabit the region. This includes bald eagles and salmon, and the relationship they have.
EagleWatch concluded on New Year’s Day and shortly after that we squeezed in one more count, the biggest of them all: the 37th Annual Brackendale Winter Eagle Count on Sunday, January 8th, 2023.
The Squamish Environment Society and EagleWatch would like to extend a tremendous thank you to all 28 of our volunteer EagleWatchers. Long-term monitoring data such as this does not come easily and requires boots on the ground and eyes looking through binoculars to collect. Thank you so much: we appreciate your dedication and effort.
The 2023/2024 EagleWatch season will commence on Saturday, November 4th, 2023. Come count with us! We’re welcoming new and experienced EagleWatch volunteers. To inquire, please contact eaglewatch@squamishenvironment.ca, or send us a message on social media! You can also visit our SES booth at the Brackendale Fall Fair on Saturday, September 9 to find out more about EagleWatch and all of our programs and projects.
Photo above by Brian Aikens: One of our resident pairs of eagles was setting up housekeeping in Squamish this spring.