A significant number of migrating owls has resulted in a busy period for researchers at the Mugaha Marsh Banding Station in northern British Columbia, with an unprecedented influx not seen in years.
Jeannine Randall, a bird biologist from the Mackenzie Nature Observatory, located approximately 200 kilometers north of Prince George, expressed astonishment at this year’s owl migration. Typically, the station catches around 100 owls, but this season they have already caught 266 with two weeks remaining, marking a record-breaking year.
The surge in owl numbers has posed a unique challenge, causing a shortage of the specific tracking bands required to monitor the birds. According to Randall, the station faced a shortage of larger bands used for saw-whet owls due to back-ordered supplies.
Despite reaching out to other organizations for assistance, it became evident that the owl population surge was widespread, leading several stations to encounter similar band shortages. Randall attributes the increase in owl numbers to a plentiful prey base, mainly consisting of small rodents such as mice, deer mice, and voles.
While the spike in owl numbers at the Mackenzie station is promising, it may not reflect the overall trend for owl species in the province. Rémi Torrenta, a biologist with Birds Canada, highlighted that many owl populations have been declining over the past 25 years, with some species stable or increasing, like barred owls, while others, including northern saw-whet owls, are decreasing.
Torrenta explained that the current abundance of owls is likely part of a documented four-year cycle, where a surplus of owls leads to a subsequent crash in the rodent population, forcing owls to migrate south in search of food—a phenomenon known as a mass eruption.
To track owl populations and trends, Birds Canada coordinates the Nocturnal Owl Survey, a citizen science program that relies on volunteers nationwide to monitor owl numbers each spring. This volunteer effort aids in better understanding owl populations and migration patterns across the country.
The banding project at the Mackenzie Nature Observatory plays a vital role in scientific research, providing essential data for monitoring owl populations and migration routes. Recently, the station recaptured an owl originally banded in Victoria in 2024, offering insights into the species’ travel behaviors.
Randall emphasized the importance of gathering such information for making informed conservation decisions and enhancing species understanding.