Eastern bluebird behavior (1 Viewer)

[greygarious]

New recruit here; apologies if this post is in the wrong pew. I know that these birds live in my suburban Boston town but until I expanded from November to April birdfeeding in 2024, I had never seen one. Literally, one bluebird on a handful of Spring days, on one of which there were two at the same time. Two days ago, to my surprise and delight, there were at least six in the "waiting room": an overgrown arborvitae just outside my living room, where Brome feeders hang from the soffit above the windows, which are 9-10 feet above the ground. They jousted with the everpresent team of goldfinches for seats at the bar. The day was blustery, 30-ish degrees, with intermittent rain. They ignored the whole black oil sunflower, preferring the sunflower hearts/chips. I am now disabled, spending most of my day seated a few feet from the windows, often glancing at the birds there. Since it is well out of migration season, I assume these bluebirds live nearby and am puzzled that they appear so sporadically. A couple of acres of woods, with oaks, maples, and huge pine trees abut my lot on two sides. Sadly, neighbors felled trees on their property in recent years, but there has been no major land clearing, nor construction, in decades.
Can anyone explain why the bluebirds visit so unpredictably?
Thanks in advance, Erica