Bluebird Building Behavior

 While the male bluebird is all about attracting the female to the nest, that's about the extent of his contribution to the nest building activity.

 Picture from Oklahoma Birds & Butterflies

In the comical, typical male fashion, the male bluebird brings nesting material to the hole, but that's where his contribution to nest building ends.  He'll pop in and out, waving his wings while perched above the hole, but it's the female bluebird who actually builds the nest an incubates the eggs.