Tree Swallow
(Tachycineta bicolor)
I happen to believe that the Tree Swallow is the most attractive of all the swallows in this part of the world, but I have to say they are complete bullies when it comes to stealing homes from bluebirds, especially man-made nesting boxes. Most of the swallow species are slightly smaller than Eastern Bluebirds, but the Tree Swallow is a bluebird's worst nightmare when it comes to possession and bragging rights over nesting boxes. Even if a bluebird has already occupied a nest box, a Tree Swallow will harass the bluebird until it gives up its home and moves elsewhere. I've seen this happens dozens of times over the years at the Cold Creek Conservation Area in King Township. The ousted bluebirds have to take what's left over and often it is not what they prefer. Wary and timid bluebirds like to nest in wide open spaces where they can keep an eye on things. They do not prefer to be hidden away in shrubby bushes or short trees where they cannot see all around their nesting sight.
Please comment if you wish.
BarrytheBirder