A couple of years ago I found out that a work colleague was also into birding and that he had a mountain bluebird nest box monitoring run. For those not familiar with this program, it started in the 1970’s when mountain bluebird numbers were on the decline due to loss of nesting habitat. They typically nest in tree cavities at the edge of wooded areas and are quite particular about where they nest.

There is also a lot of competition for nest locations amongst other birds