Although this nestbox was located in prime bluebird habitat (open, mowed grass with some scattered trees for perching), the wooden post it was mounted on offers easy access to mice. More baby mice were inside the “nest”. (This is one reason why you don’t want to stick your bare hand in a box while monitoring.) Mice will eat bird eggs, so if an unfortunate bird did nest here, their attempt to reproduce would be jeopardized. Mice will also urinate inside boxes (yuck!) and can spread Hanta virus, although this is rare.
Mammalian scratches were visible on these posts and boxes. Cats have killed chickadee parents here, leaving a nest full of dead babies behind. These boxes have since been removed.
MORE INFORMATION:
“Dr. Bobby Corrigan, noted rodentologist and award-winning pest management consultant, states that if you can put a #2 pencil into a hole, a mouse would be able to get through it as well. Others like to use the dime as an example of the width a mouse can exploit. Basically, we’re talking about a space that is roughly ¼-inch across.”
– VictorPest.com
