- The types of birds that visit and thrive on the islands of Yáláƛi, the Goose Island Archipelago, a Canadian Important Bird Area, have changed dramatically in the past 70 years.
- The Haíɫzaqv people, stewards of the land for millennia, and academics have analyzed ecosystem data and traditional knowledge to uncover the drivers of change.
- The discovery that varying patterns of mammals, human use and natural disasters has reshaped biodiversity on the archipelago offers vital lessons for stewardship elsewhere on Haíɫzaqv territory.
In the summer of 1948, naturalist Charles J. Guiguet spent four months on the Goose Island Archipelago, a cluster of tree-covered islands with wild, rocky beaches located off the central coast of British Columbia, Canada. He noted the birds and animals he spotted in his field notebook. That summer, Guignet saw an abundance of orange-crowned warblers, dark-eyed juncos and red crossbills, but nowadays visitors would see far fewer of those birds in comparison with other species such as bald eagles or Pacific wrens.
“It’s scary to look at how fast things are changing,” said Dúqva̓ísḷa William Housty, director of the Heiltsuk Integrated Resource Management Department (Heiltsuk is the anglicized version of Haíɫzaqv. “We know what sort of conditions certain birds prefer, and they are conditions we haven’t seen in a long time.”
Haíɫzaqv First Nation stewards partnered with scientists to compare Guiguet’s findings with contemporary surveys and citizen science data gathered in the last 15 years. Their collaboration revealed dramatic shifts in bird populations and pointed to drivers of change.
“The collaboration helped highlight what is happening and how to respond to those changes,” Housty said. “And it is allowing us to learn lessons on how we need to care for the rest of our territory.”


Establishing a baseline
In 2010, the energy company Enbridge Inc. applied to build the Enbridge Northern Gateway Pipelines project, which would have increased oil tanker traffic in Haíɫzaqv territory. Concerned about the impacts of possible oil spills on local ecosystems, the Haíɫzaqv stewards surveyed forests and seabirds and simultaneously collected data on wolves, deer, mink, river otters and other sea mammals on Goose Island (also called Yáláƛi), part of their territory, to establish a baseline biodiversity dataset.
“We wanted to take an inventory of what was there so we could assess the impacts of a spill,” Housty said.
Although the pipeline wasn’t built, the Haíɫzaqv stewards and scientists collaborated to monitor biodiversity on the archipelago moving forward. In 2011 and 2015, Simon Fraser University researchers conducted similar surveys and the team also gathered data between 2010 and 2023 from eBird contributors who keep track of bird sightings.
To uncover the drivers of change, the collaborators looked to Indigenous knowledge that was passed down through generations as well as the contemporary Indigenous knowledge held by Haíɫzaqv community members.
“One of the really cool things about this study is how Indigenous local knowledge has opened our eyes to some of the different factors that have impacted bird communities that we probably wouldn’t have stumbled onto,” said lead author ecologist Debora Obrist, previously at Simon Fraser University and now at the British Columbia Ministry of Forests.

Insider knowledge
The team found that some types of birds were more abundant according to the data collected between 2010 and 2023, such as different species of warblers, whereas other bird species — like the red crossbill (Loxia curvirostra) and dark-eyed junco (Junco hyemalis) — appeared to be less prevalent on the islands in comparison with 70 years ago. They published their findings in Ecology and Evolution.
So, what caused the changes?
The team found clues in the Haíɫzaqv Traditional Use Study, a compilation of interviews with Haíɫzaqv elders who had spent up to eight months of the year living on the islands. “It represents the experiences of people who lived through the same conditions as other species on Goose Island,” Housty said. “And it is not just one generation of people that supplied the data. They also talk about what they were taught, and their ancestors were taught, so it goes a long way back in time.”
The researchers used Indigenous knowledge and the survey data to identify several key factors influencing biodiversity. Black-tailed deer (Odocoileus hemionus columbianus), which arrived after the naturalist Guiguet’s stay, reduced vegetation that songbirds rely on. Wolves, appearing after 2004, have since helped the understory recover by preying on deer. Mink and river otters, also absent in 1948 until they returned for unknown reasons, now prey on ground-nesting birds.
The Haíɫzaqv elders talked about harvesting seaweed, geese, ducks, deer, halibut and cod on the island, but the Haíɫzaqv have visited the island much less in the last two decades, Housty said. While none of the surveys showed a reduction in geese or ducks, contemporary Indigenous knowledge revealed few of these birds in the popular hunting areas anymore.
“This example shows how local knowledge shines a light on ecological changes that you would miss as an external scientist,” Obrist said.
A model for conservation
The elders also talked about the impacts of a 1964 tsunami that changed the islands’ shores from sandy to rocky and muddy, impacting which birds, or prey, were able find food or habitats. “The study really highlighted how many different things can impact birds outside of industrialization,” Obrist said. “And we need to consider these factors in ecological studies.”
Yáláƛi is a place the nation has deep, millennia-old and extensive knowledge of, stretching to current times, said environmental biologist Kyle Artelle of the Center for Native Peoples and the Environment in New York, who was not involved in the study. “This paper adds the collaborators’ knowledge and expertise to that existing and deep knowledge base, providing even more information the nation can use to support their governance, use and stewardship of the land,” Artelle said.
The outside collaborators would have likely missed key ecological insights had they not followed Haíɫzaqv direction and guidance, Artelle said. Instead, it uncovered the complexities of ecosystem changes and revealed factors that can influence bird populations and biodiversity shifts elsewhere on Haíɫzaqv territory.
“Understanding biodiversity change is very difficult, and collaborative work like this shows a successful way in interpreting environmental change over time,” said conservation biologist Brian Starzomski of the University of Victoria. “In a complex world, collaboration and combining ways of knowing leads to deeper understanding.”
As such, the collaboration has emphasized the value of traditional ecological knowledge in understanding dynamic systems to the academic community, Housty said.
“The dovetailing of Western science and traditional knowledge was able to tell a powerful tale of some valuable species in an important part of the territory,” Housty said.
Banner image: A Pacific wren (Troglodytes pacificus). Image by John Reynolds.
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Citation:
Obrist, D. S., Pendray, E. J., Field, R. D., Housty, W., Dennert, A. M., Scoville, G. W., … Reynolds, J. D. (2024). Comparing historical and contemporary observations of avian fauna on the Yáláƛi (Goose island) archipelago, British Columbia, Canada. Ecology and Evolution, 14(12). doi:10.1002/ece3.70464