A surge of migrating owls has researchers at the Mugaha Marsh Banding Station working extra hours as the birds travel through northern B.C. in numbers not seen for years. Jeannine Randall, a bird biologist for the Mackenzie Nature Observatory, located about 200 kilometers north of Prince George, described the year as exceptional. Normally, around 100 owls are captured, but this season they have already caught 266 with two weeks left, setting a new record.
The sudden increase in owl numbers created an unexpected challenge: a shortage of the regulated tracking bands required for monitoring the birds. Randall explained that they were particularly running low on one size of bands due to a delay in the delivery of bands for saw-whet owls, the primary species they target.
Despite reaching out to other organizations for assistance, they found that many stations were experiencing similar shortages due to the widespread owl boom. Randall attributed the spike in numbers to an abundance of small rodents, the main prey of the owls, with most of the captured owls being hatchlings from this year.
While the spike in owl numbers at Mackenzie is positive, it may not reflect the overall trend for owl species in the province. According to Rémi Torrenta, a biologist with Birds Canada, many owl populations have been declining over the past 25 years, including the northern saw-whet owls.
Torrenta suggested that the high owl volume observed this year is likely part of a documented four-year cycle, where an excess of owls leads to a subsequent crash in the rodent population. This results in owls migrating farther south in search of food, known as a mass eruption.
To monitor these trends, Birds Canada oversees the Nocturnal Owl Survey, a citizen science program that relies on volunteers nationwide to track owl numbers each spring. This initiative helps track owl populations and migration routes, providing valuable insights into owl conservation efforts.
The banding project at the Mackenzie Nature Observatory plays a crucial role in broader scientific research by offering essential data for monitoring owl populations and migration patterns. Recently, the station recaptured an owl banded in Victoria in 2024, shedding light on the species’ travel behaviors and emphasizing the importance of ongoing research for effective species management.
Overall, the surge in owl numbers in northern B.C. this year highlights the complex interactions between owl populations and their prey, underscoring the need for continued monitoring and conservation efforts.