Nest Box Heat Shield And Color Tests

By Neil Yeager


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 2F-3F 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 87.8F the dark brown test box was 108.68F. At 4:30PM the gray box was 105.08F.


Video Link:


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 88.9F the weathered test box was 105.8F. 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 and Sunny

Video Link:



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 another 2F-3F.



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.