We are happy to have Western Bluebirds nesting in our front yard again. Although there's no way to be totally certain, based on their habits and tolerance of us, they seem to be the same pair from last year. They were great parents, and raised 15 fledglings in 3 broods.
The female spent about 10 days building the nest. Most of the nest was made of weeds and fine grass that she pulled from our yard and the neighbors' yards, and pampas grass seed tufts. She worked in a few dead leaves and short pieces of plastic twine.
This morning, she laid her first egg, same date as last year. The attached photo shows the view using a bicycle mirror and a spotlight to see inside the nest.