Bluebirds in the Vineyard

We have been involved in canopy management ever since fruit set. Recently, when we were doing our leaf pulling detail, we came across a row with 2 bluebird nests. Earlier, I had seen an empty nest and then more recently a nest with 3 fledgling bluebirds! This makes it the most bluebird nests that we have ever seen in the vineyard.
I think that our tall grafted vines provided the right kind of scaffold for the bluebird to build it's nest. It is a tiny but beautiful nest. Here is one with three eggs that I saw on July 30th.
In order to learn more about the bluebirds, I went to a site that told me all about Bluebirds from Egg to Empty Nest. I was interested to know when the eggs would hatch. I went back to the nest several times from July 30th until August 6th when I saw the tiny, tiny bluebirds. Here are my photos:

Seeing all these bluebirds got me interested in knowing where the phrase "bluebird of happiness" came from. I looked up many sites on the Internet but I liked this the best from Anne Koplik:
Spotting a bluebird is usually recognized as a symbol of joy and happiness that you’ll be expecting in the future. The symbol of the bluebird is found in many cultures and dates back thousands of years. It can also represent hope, cheerfulness, prosperity, good health, and renewal coming your way!