I learned a couple of new things the other day while reading through a new book by Richard Beamish and Gordon McFarlane (The Sea Among Us).
I was of the impression that the Salish Sea was just an alternate name for the Strait of Georgia, but in fact the Strait of Georgia is just one component of the Salish Sea which also includes Puget Sound and Juan de Fuca Strait. The second bit of trivia I learned was that roughly 75 population of British Columbia’s population lives near the Salish Sea.
There is an interesting coincidence to do with the Salish Sea with regard to human and bald eagle populations in that about 75 per cent of the population of the entire west coast Bald Eagle population reside in the Salish Sea area during the winter.
Bald eagles have gone through a lot over the last 100 years, being subject to DDT and other harmful chemicals combined with direct persecution where bounties were paid to eliminate completion for “our fish.” By the late 1950s, bald eagle numbers had diminished significantly, threatening to disappear. Since we started treating them better, bald eagles have made a miraculous recovery. According to research by Elliot et al. (2011), wintering and resident eagle populations in the Salish Sea quadrupled between the early 1980s and late 1990s and have since stabilized.
So why do we get so much of the bald eagle population localized in our back yard over the winter? The short answer is food and temperature. Coastal bald eagles have adapted to follow salmon runs. Shortly after bald eagle fledglings have left the nest (early to mid-August), salmons runs begin in Alaska, and on the mid and north coast of British Columbia. Many of our resident eagles will migrate northward to take advantage of the early salmon runs. As the salmon runs progress in a southward direction, the Alaskan eagles (and our wayward resident eagles) follow the salmon runs down to the Salish Sea. Bald eagle winter populations in the Salish Sea tend to be highest when there is a combination of low temperatures in Alaska, and high chum salmon returns in the Salish Sea.
Like bears preparing for winter hibernation, bald eagles need to prepare for a winter period of sparse food.
The majority of bald eagle mortality occurs during mid-winter between the last Chum Salmon runs in December and the annual arrival of spawning Herring mid to late February. Between that period, eagles will often be forced to hunt less desirable prey species or increase scavenging.
- Eagle Festival 2015
After a long winter period with little food, the arrival of spawning herring is literally a life saver for many eagles. It is this anniversary that we celebrate with the Bald Eagle Festival each year in Campbell River. In fact, MARS will be hosting the 10th annual “Bald Eagle Festival” in Campbell River at the Maritime Heritage Centre on Saturday, Feb. 21. Make sure to mark this on your calendar as this is a great family event and an important fund raising event for MARS. The theme this year is “The Rearing Period” highlighting the struggles birds face rearing their young. Please watch for further details over the next few weeks.
To report injured wildlife please call 250-337-2021. To read our latest updates and upcoming events visit www.wingtips.org. Please consider volunteering or donating monthly to MARS; we rely heavily on your investments in wildlife.