A significant number of migrating owls have been keeping researchers at the Mugaha Marsh Banding Station busy, passing through northern British Columbia in unusually high numbers. Jeannine Randall, a bird biologist at the Mackenzie Nature Observatory, located about 200 kilometers north of Prince George, described this year as exceptional. Typically, around 100 owls are caught during the season, but this year, they have already captured 266 with two weeks remaining, setting a new record.
The surge in owl populations caused a shortage of the specific tracking bands required for monitoring the birds. According to Randall, the station faced a scarcity of larger bands primarily used for saw-whet owls, the main targeted species, as they were on backorder from the bird banding office.
As the station sought assistance from other organizations, they discovered that the owl boom was a widespread phenomenon, leading to similar shortages at many stations. Randall attributes the increase in owl numbers to a plentiful supply of small rodents this year, the main prey for these birds, such as mice, deer mice, and voles.
Although the high owl count at Mackenzie is promising, it may not reflect the overall trend for owl species in the province. Rémi Torrenta, a biologist at Birds Canada, highlighted that many owl populations have declined over the past 25 years, with some stable or increasing species like barred owls. This decline is likely affecting various owl species in British Columbia, including the northern saw-whet owls.
Torrenta explained that the spike in owl numbers this year is likely part of a well-documented four-year cycle. When owl populations increase significantly, there is a subsequent crash in the rodent population the following year, leading to a mass migration of owls in search of food. This phenomenon, known as a mass eruption, drives owls to migrate southward to find sustenance.
To monitor these trends effectively, Birds Canada coordinates 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 patterns, providing valuable data for scientific research.
The banding project at the Mackenzie Nature Observatory plays a crucial role in this broader research effort by providing essential data on owl populations and migration routes. Recently, the station recaptured an owl that was originally banded in Victoria in 2024, shedding light on the species’ travel behaviors and patterns.
Understanding these dynamics is essential for effective conservation and management decisions. By analyzing such information, researchers can gain insights into owl behavior and populations, aiding in the protection of these fascinating birds.