Bluebird Boxes
Once a rare sight in Ontario due to habitat loss and competition from invasive species, the Eastern Bluebird (Sialia sialis) is now a vibrant success story at Hullett Marsh. We maintain a sprawling network of over 150 nesting boxes strategically positioned across our sun-drenched grasslands and hayfields. These boxes are carefully designed to mimic natural tree cavities, providing the perfect vantage points for these insect-eaters to hunt while offering a secure "primary residence" that protects them from larger competitors. To ensure the highest success, we often "pair" our boxes; this clever strategy allows territorial Tree Swallows (Tachycineta bicolor) to claim one box while leaving the neighboring one free for a pair of Bluebirds to nest in peace. Because Bluebirds are sensitive to their environment, their nesting success serves as a direct biological "report card" on the health of our grassland ecosystems, often allowing healthy pairs to raise two separate broods in a single summer.
Blue is gold...
The health of our Bluebird program depends on the rigorous stewardship we perform during the winter months. Because these boxes are scattered across thousands of hectares of meadow, our team spends the season navigating the property to inspect every site, clearing out old nesting material and sanitizing the interiors to prevent the spread of parasites. During this time, we act as citizen scientists by meticulously documenting the remnants of the previous season—counting unhatched eggs and successful nests to calculate the annual productivity of the program. This "forensic" data is vital, as it allows us to identify shifting habitat trends and relocate boxes that have been impacted by invasive species. We finish our winter rounds by orienting boxes away from prevailing winds and reinforcing predator guards, ensuring that when the "sky-blue" males return in early spring, they have a clear, safe flight path to raise the next generation.