Miriam - your information about House Wrens preferring edge habitats for nesting is correct; but wrens also have a habit of filling boxes with false nests which they never use just to keep would be competition at bay. Perhaps this explains your wren's behavior, or you have a crazy, aggressive wren.
I checked today 55 nest boxes that I monitor near Schenectady, NY for swallows, bluebirds and wrens. Several partial swallow clutches, only one complete; most bluebird clutches complete; but despite several wren nests, no eggs yet. The most advanced wren nesting was one box with a lined deeply cupped twig nest. All others were just collections of twigs, some of which were built atop prior, this-season attempts made of grass/pine needles by swallows or bluebirds.
House Wrens are not good communal citizens in a large nest box colony. If you have one in a lone box in your garden, enjoy the loquacious song and energetic activity of what seem like model avian citizens. Otherwise, they are a scourge to swallows and bluebirds in larger settings.
From: Miriam Lawrence <[log in to unmask]>
To: VTBIRD <[log in to unmask]>
Sent: Mon, May 14, 2018 2:26 pm
Subject: [VTBIRD] House Wren demolition crew
I was playing around with my scope yesterday, enjoying the activity around
our nestboxes, when I caught a bit of a drama - a House Wren systematically
removing the contents of a Tree Swallow nest from a box, while the current
occupants tried, and failed, to resist. I got some of this on video, which
I've edited together. Sorry for the quality - this was all handheld and at
a good distance away. A good iPhone scope attachment is on my wish list!
What I find most interesting is that this box is in the middle of a field,
just a tree or two around (and not close to the box), and we've never had
wrens near it before that I've seen. And, we've got another box in another
location, also quite exposed and not in a transitional zone, that has been
claimed by a different pair of wrens. That female was hard at work bullding
yesterday while her mate sang away nearby. No mother's day relaxation for
her! I got a little video of that too.
Am I misinformed that HOWR prefer to nest near edge? Or did these guys
just not get that memo?
-- Miriam Lawrence, Monkton