On 5/20/2022 we peeked into the nest box, and found several eggs. Not countable, because of the feathers in the box meant to hide the eggs from predators. Since then I have peeked several times more.

The female adult was incubating the eggs.  I noticed the adults going in and out of the box on June 3 since  the eggs had hatched and they were bringing food to the hatchlings.  After two weeks in the box the nestlings had grown enough so they were full size and had gained some flight feathers.  On June 21 most young fledged out of the box, ready to learn how to fly and hunt for their own food: flying insects.

On June 22 the adults coaxed the last young bird to fly.  A few days later, we saw 3 of them perching on a branch looking over the pond.