A significant number of migrating owls have kept the Mugaha Marsh Banding Station researchers busy, with a remarkable influx passing through northern British Columbia, a rare occurrence in recent years.
Jeannine Randall, a bird biologist at the Mackenzie Nature Observatory, located approximately 200 kilometers north of Prince George, expressed excitement over the extraordinary year they have had. Typically capturing around 100 owls, they have already caught 266 this season, with two weeks remaining, setting a new record.
The surge in owl numbers posed a unique challenge as there was a shortage of the specific tracking bands required to monitor the birds closely. The station faced a scarcity of larger bands, crucial for saw-whet owls, the primary species they focus on, as these were on back-order from the bird banding office.
Despite reaching out to other organizations for assistance, it became evident that the owl population increase was a widespread phenomenon, causing similar shortages at many other stations. Randall attributed the rise in numbers to an abundance of small rodents, the main prey for the owls, particularly young birds hatched this year.
While the spike in owl numbers in Mackenzie is promising, Rémi Torrenta, a biologist at Birds Canada, highlighted a contrasting trend, noting a decline in many owl species’ populations over the past 25 years. He mentioned that while some species remain stable or show growth, the majority, including northern saw-whet owls, are on a declining trajectory.
Torrenta explained that the current surge is likely part of a documented four-year cycle, where an excess of owls leads to a subsequent crash in the rodent population, prompting owls to migrate south in search of food. This pattern, known as a mass eruption, is a natural occurrence in owl behavior.
To monitor these trends effectively, Birds Canada coordinates the Nocturnal Owl Survey, a citizen science initiative engaging volunteers nationwide to track owl numbers each spring. These programs play a vital role in understanding and conserving owl populations.
Randall emphasized the significance of the Mackenzie Nature Observatory banding project in contributing essential data for studying owl populations and migration patterns. Moreover, the recent recapture of an owl banded in Victoria in 2024 provided valuable insights into the species’ movement patterns, highlighting the importance of ongoing research for informed conservation efforts.