WHAT IS A BLUEBIRD NEST BOX?
There are many good Bluebird nest box designs. Such as Peterson’s, Gilbertson’s, NABS, slot box, and the many variations of these boxes. What constitutes a good box is primarily a box that the bluebird’s will use, you can monitor, and the predators can’t get into. The entrance hole for Eastern and Western Bluebirds should be one and one-half inches in diameter (the Peterson Box hole size is an oval (1&3/8″ x 2&1/4″) and Mountain Bluebirds should have a one and nine-sixteenths inch hole or (Peterson, 1&1/2″ x 2 1/4″). Not to confuse the issue but a well respected bluebirder, Keith Kridler, makes the following comments on the use of the oval Peterson entrance: “Well the Peterson Oval entrance 1&3/8” wide is a KNOWN AND PROVEN entrance that allows starlings from all over north America to “easily enter and leave nestboxes.” The last is a quote from Kevin Berner’s article! For the last 70 years bluebird conservationists have fought to educate the public to use an entrance hole to “positivel
