Recently a bluebird landlord told me that when he recently checked his bluebird nesting boxes, he found three dead bluebird hatchlings.  Since there were no apparent clues that revealed the cause of their deaths, he wanted to know that since the birds he found the young birds during a stretch of unseasonable cold weather, could the frigid temperatures inside the box could be responsible for the birds’ untimely deaths. He also wanted to know if plugging the ventilation holes found on each box would help preventing this from happening again.

       The answer to both questions is yes; extremely cold weather can cause the death of bluebird hatchlings.  In Georgia, bluebirds typically begin nesting in late February and early March.  This means that bluebirds are nesting in the latter stages of winter. As such, there is a good chance that we will experience cold weather before spring arrives on March 20.  For example, just two nights ago, after a weekend when temperatures soared to 80ºF, the temperature dropped to 22ºF.

       The North American Bluebird Society recommends that temporarily plugging ventilation holes during both cold and wet weather can benefit the hatchlings.

       Keep in mind, that the ventilation holes are designed to prevent overheating.  As such, once there is little chance that exceptionally cold weather will return, uncover the ventilation holes.