Nest box paint: yes or no? The results are in!

By Steven Shumborski

Grey fill around the number in table indicates a painted box, Tan colour is a bare plywood box.

In November 2017 I installed 21 new nest boxes on the Birds Eye Ranch east of Waterton Park. The land owners have seen bluebirds in the area but there have not been any nest boxes in the area for many years.

Ten of the boxes were new plywood, 11 of the boxes were painted grey. The boxes were alternated painted-unpainted along a road distance of 4.1 miles. The average spacing is 310 metres with a range from 260 to 640 m.

In the 2018 nesting season the bluebirds nested in seven of the 11 painted nest boxes, and one of the 10 unpainted boxes.

The 2019 nesting results from the Birds Eye Ranch show equal numbers of bluebirds nesting in painted and unpainted boxes.

Five bluebird nests in painted boxes, five bluebird nests in unpainted boxes. By the second nesting season the painted and unpainted boxes are chosen equally by the bluebirds for nest sites.

I continue to paint the new boxes with flat finish grey stain or paint to protect the plywood and extend the life of the box.