A significant surge of migrating owls has put researchers at the Mugaha Marsh Banding Station in overdrive, with a remarkable number of birds passing through northern B.C., marking an unusual event not witnessed in years.
Jeannine Randall, a bird biologist at the Mackenzie Nature Observatory, located approximately 200 kilometers north of Prince George via major highways, described the season as exceptional. Typically, around 100 owls are captured, but this year, they have already caught 266 with two weeks remaining, setting a new record.
The sudden increase in owl numbers posed a challenge due to a shortage of the specific tracking bands needed to monitor the birds accurately. The station faced a scarcity of larger bands crucial for saw-whet owls, the primary species targeted, 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 influx was widespread, causing various stations to encounter similar band shortages. According to Randall, the rise in owl numbers is likely linked to prey availability, with most of the captured owls being young birds hatched this year, thriving on an abundance of small rodents such as mice, deer mice, and voles.
While the heightened owl presence at Mackenzie is promising, it may not reflect the overall situation for owl species in the province in the long run. Rémi Torrenta, a biologist at Birds Canada, pointed out that several owl populations have been declining over the past 25 years. He indicated that while some species like barred owls are stable or increasing, many others, including northern saw-whet owls, are on a downward trend.
Torrenta explained that the surge in owl numbers observed this year is likely part of a well-documented four-year cycle, where an overabundance of owls leads to a subsequent crash in the rodent population the following year, forcing owls to migrate farther south in search of food, known as a mass eruption.
To better monitor these trends, Birds Canada oversees the Nocturnal Owl Survey, a citizen science initiative involving volunteers nationwide to track owl populations each spring. Such programs help in tracking owl numbers and trends across the country, providing valuable insights into owl behaviors and movements.
The banding project at the Mackenzie Nature Observatory plays a crucial role in broader scientific research, offering essential data for monitoring owl populations and migration routes. Recently, the station recaptured an owl originally banded in Victoria in 2024, shedding light on the species’ travel patterns and emphasizing the importance of such monitoring efforts for informed conservation decisions and species understanding.