In June 2025, routine monitoring of the Western purple martin (Progne subis subis) nest box structure in the Squamish River Estuary turned into an unexpected and rewarding discovery. Among the familiar swirls of activity at the colony was a single subadult purple martin bearing a leg band, a small detail that would spark a six-week quest for answers led by project facilitator and volunteer John Buchanan.
Spotting a banded bird is exciting. Reading the band, however, is another matter entirely. John took on the challenge with determination, spending countless hours stretched out in long meadow grasses, quietly staking out the nest boxes with his camera. Most days ended with little to show for the effort. To capture the band number, he had to get close enough for his zoom lens to focus, all while the bird hopped, perched, and took flight. As John put it, “It’s like trying to read a license plate, except it’s round, hops about, and the letters are the size of a pea.”
Eventually, patience paid off. With the band code finally deciphered, John began the next phase: tracking down the bird’s origin. That search proved more difficult than expected. The code was shared with numerous organisations and purple martin experts, but weeks passed with no clear answers.
Nearly six months later, the breakthrough arrived. The North American Bird Banding Program, a partnership between the US Geological Survey and the Canadian Wildlife Service, confirmed the bird’s history. The subadult purple martin observed in Squamish had been banded on August 1, 2024, near Fort Langley, BC, when it was still a flightless chick. Less than a year later, after completing its first migration to South America and back, the young purple martin had returned to British Columbia, choosing Squamish, rather than its natal site, as its first breeding location. The bird settled into Box C, laid five eggs, and successfully fledged two chicks.
Why This Matters: Understanding Purple Martin Migration and Settlement
Purple martins spend their nonbreeding season in South America, undertaking long and dangerous migrations each year. Age plays a key role in when they return and where they settle. Older adults typically arrive first in May and show strong site fidelity, returning to colonies where they’ve nested successfully before. Subadults, or yearlings, arrive later in June and must select a nesting site for their first breeding season, often choosing new or growing colonies.
This makes subadults especially important to colony stability. Each one that successfully recruits strengthens the future of the population.
The Bigger Picture: Nest Boxes and Community Conservation
This single bird’s journey also highlights the importance of British Columbia’s long-running, volunteer-driven artificial nest box program. Initiated in 1986, the program began at a critical moment; by that time, purple martins in BC had declined to just 10 individuals province-wide.
Through decades of coordinated effort, that trajectory has been dramatically reversed. Today, British Columbia supports over 1,200 breeding pairs across more than 120 colonies, with nearly all of these birds relying on human-built nest box structures.
The Squamish colony, now managed by Nature Squamish, began in 2015 through an initiative led by the Squamish River Watershed Society with the installation of its first nest boxes. Since then, dedicated volunteers and targeted habitat enhancements have allowed the colony to steadily grow, making it an appealing destination for dispersing subadults like this remarkable Fort Langley bird.
This blog post was written by Davina Dubé, Purple Martin Recovery Project Coordinator.