Kroodsma and Verner 2014).
I suspect these wrens are males, but there is no way of telling for sure. In any event, the wren in the bottom photo is one angry bird. This singing bird almost stood on its head, pointed its tail at us, and let us know what it thought of our being in its territory. Alternatively, this wren may have been upset at the presence of the Marsh Wren in the first photo.