In 2010 I decided to
develop and run a series of tests to determine how exterior colors and
heat shields affect temperatures inside bird nest boxes. In the
beginning I used 4 boxes. Dark brown, gray (to simulate a weathered
box), light tan painted and a light tan painted with light tan PVC
shields. All boxes are identical in size, shape and design. Results indicated that the light colored boxes were cooler as
seen in the data below. An additional 2°F-3°F of cooling can be obtained
by adding light colored heat shields to a light colored box. Other boxes
were hotter. At 4:30PM with ambient temperature at 87.8°F the dark brown
test box was 108.68°F. At 4:30PM the gray box was 105.08°F.
Then in 2011 I was able to
obtain several weathered boxes from the builder (Thanks Greg Seaford of
NC) and also added a new unpainted box to the tests. In addition a
weathered box with dark shields was added to see how it would perform
since some people might not want a light colored box in their yard. All
boxes are identical in size, shape and design. Results of these
tests show that weathered boxes do not perform well in direct sun and
are potentially dangerous to baby birds. At 4:00PM with ambient
temperature at 88.9°F the weathered test box was 105.8°F. All data was collected and then
entered into charts and graphs to make it easier to analyze. Also all
tests were videotaped and links to videos are also included.
May 25, 2011 Test
Weather Conditions: Clear
The most important factor to
reduce heat is color of nest box. On sunny hot days light colored heat
shields can be added to light colored boxes to reduce temperatures
Use a light colored paint and/or heat
shields to protect your nest boxes.
There was a question about ventilation in
these boxes. There is a 1/2in high 4in long vent in the front and also a
pair of vents in the upper back. See photos below.