This "snag tube" is based on a design tested and recommended by researchers at Cornell. http://www.birds.cornell.edu/
We have 3 of these tubes placed in the quiet seclusion of the wild woods.
We positioned this tube about 12 feet up, in a young Ash tree that grows among Elm, Bitternut Hickory, and Boxelder trees. Wild Grape vines and pesky Buckthorn provide additional coverage in the understory.