Georgians are well aware of the fact that during the summer the temperature soars into the high 90s and above. However, this year the thermometer seems to be reaching these lofty numbers more often than ever before. While these temperatures put us under a lot of stress, they are especially harmful to eastern bluebirds trying to nest during these difficult times.
Bluebirds nest in Georgia from February into September. During this time, bluebirds can produce up to three broods.
Consequently, there is a good chance untold numbers of bluebirds are currently trying to nest during these torrid temperatures.
For many of these birds, one factor that will play a key role as to whether or not these nesting efforts are successful is the color on the exterior of the nest box they are using. Let me explain.
The temperature inside a nesting box can reach 120ºF or more. In addition, these temperatures can 20º higher than the air outside a box. One way you can moderate the temperature in inside a box is to paint the outside of the box a light color. Boxes painted white and other light colors absorb less light than those than darker colors such as brown.
This is critical to the success of the nesting attempt because eggs develop best in temperatures ranging from 96.8 to 104.8º. In addition, bluebird’s eggs and nestlings simply cannot survive when the temperatures rise above 107º.