Here's the rest. They've put up hundreds of nesting boxes here in Southern and Central Alberta for the Mountain Bluebirds which the Tree Swallows use, just as they use old Woodpecker cavities.
Some birds. A flock of migrating Seagulls and a family of Robins. Our Robins here have two to three broods a year.
The attrition rate must be huge or we'd be overrun with them.