How bird populations have changed on the BC central coast, new study
New paper shows how historical natural history data can improve our understanding of ecological phenomena, particularly when evaluated with contemporary Indigenous and place-based knowledge.
On the islands of Yáláƛi, the Goose Island Archipelago, on British Columbia’s central coast, the composition of birds singing their forest melodies has changed over the last seven decades.
This area has been important to both birds and to the Haíɫzaqv (Heiltsuk) since time immemorial.
Read this new open access journal article in Ecology and Evolution.
We used data on bird occurrences collected in 1948, and comparing it with contemporary surveys conducted by the Haíɫzaqv-led CoastWatch, Simon Fraser University researchers, and eBird contributors in recent years. We found changes in species communities over time.
For instance, while only one species of warbler was found in 1948, today at least six warbler species populate the islands, along with a dramatic relative increase in thrushes. Meanwhile, previously dominant species like the Red Crossbill and Dark-eyed Junco are no longer as prevalent.
But why have these distributions shifted so much?
In this paper, we use place-based, Haíɫzaqv Knowledge to help answer this question.
First, there have been big changes in the mammal communities on Yáláƛi, from the arrival of deer (and subsequently Goose Island’s famous coastal wolves), to smaller mammals like river otters and mink. These animals can have a drastic influence on island vegetation and bird habitat. Second, human activity has changed. Not only has declining deer abundance in recent years meant that Haíɫzaqv hunters aren’t frequenting the island as much, but the increased length of time since European colonization has meant that the impacts on bird communities of a larger Haíɫzaqv population is further in the past. Lastly, a tsunami in 1964 altered the physical landscape by removing the sandy, shore-bird friendly substrate in the large lagoon.
Why does it matter?
Increasing marine traffic in the territory due to natural resource extraction is a huge threat to both the ecosystems in the area and to the food sovereignty of the Haíɫzaqv People, which are intricately connected. This study originally came about in response to a proposed pipeline project in the early 2010s. While the pipeline in question was never built, a major diesel spill in Seaforth Channel at Q̓vúqvái (Gale Creek) in 2016, and a close call in 2017 when a fuel barge nearly ran aground onto the Gosling rocks during a storm, made it clear that it is crucial to have detailed baseline biodiversity data for this area.