By Alexandre Terrigeol
Occasionally, certain observations stand out for their exceptional nature and scientific significance. They testify to the work of numerous researchers and enthusiasts united around the same objective: to better understand migratory birds. An unlikely sighting, a ring identified, a migration traced over several years and thousands of kilometers… and here’s a story that exceeds even the most optimistic expectations.
A “recapture” by photo
On July 12, 2025, Frédérick Lelièvre observed a young Bicknell’s Thrush at one of its few known nesting sites in the province—at the summit of Mount St. Joseph, in Mont-Mégantic National Park.
Québec is home to nearly 50% of the world’s population of this species, which is listed as Threatened under Canada’s Species at Risk Act, and Vulnerable under Québec’s Act Respecting Threatened or Vulnerable Species.
To his surprise, the fledgling was being actively fed by an adult wearing both a leg band and a radio transmitter. Thanks to the photos taken during the observation, the band number was identified, allowing researchers to trace the associated data. Yet this is not the first time this individual has been discovered in this location, and his story is even more incredible.
The importance of bird banding
On June 7, 2024, Camille Bégin-Marchand and Vincent Lamarre captured a Bicknell’s Thrush that was already banded, as part of a research project led by the Canadian Wildlife Service aimed at better understanding the migratory connectivity of this declining species.
To fully appreciate how exceptional this story is, one must understand that passerine recaptures away from their original banding site are extremely rare—about 1 in 1,000—and typically occur when a bird is found dead, often due to a window collision or an unfortunate encounter with a domestic cat.
It is a common misconception that bird banding is mainly intended to obtain recapture data. In reality, it provides access to a wealth of otherwise unavailable information: age, sex, health status, presence of disease, and various morphometric measurements.
At the heart of a collaborative research project
In this case, the bird had been banded in January 2022 in the Dominican Republic—its main known wintering area—by a research team from the Vermont Center for Ecostudies, collaborators on the same research project!
Camille and Vincent then fitted the bird with a lightweight radio transmitter to continue tracking it throughout its annual cycle. These ultra-light devices (approximately 1.25 g in this case) must be detected by Motus stations distributed across the landscape in order to monitor the bird’s movements.
One such Motus station is currently operating at the summit of Mont-Mégantic to determine whether individuals fitted with transmitters will return to the same breeding site. Thanks to this collaboration, this is the first documented connection between a wintering area and a breeding site in Québec for this species.
The importance of tracking bird migration
Frédérick’s observation, then, answers their question. Not only did the transmitter provide valuable data, but the bird also returned to the exact same location… and is breeding there!
This project also builds on Camille’s master’s research at Université Laval, supervised by André Desrochers and conducted in collaboration with the Tadoussac Bird Observatory. Her work focused on the migratory strategies of three thrush species, including Bicknell’s Thrush.
Since then, the Motus network, supported by Birds Canada has expanded—along with our understanding of migratory routes and strategies—enhancing our ability to conserve hundred of species in decline. This knowledge enables us to target priority areas throughout the bird’s life cycle, in order to conserve these endangered species more effectively.
