Interesting. I know that other birds do raid nests and carry baby birds away, which is why I assumed that maybe the bluebirds do their own cleanup when a chick dies.
Sounds like they are very territorial, and almost like what happens when a new male lion takes over a pride, they kill the previous male's cubs to force the females into heat again. The females seem to have no problem with this, which never fails to disturb me...but then we can't put human feelings onto animals.
My ceramic bluebird house does have a trap at the bottom for cleaning it out, and air holes on the top. I think it is very attractive, but then, I am not a bluebird. I also wonder if it might be too hot inside, compared to wood houses... Not only have no birds of any kind ever nested in this thing, but I have never once in several years even seen any just checking it out. They take more time rummaging through and inspecting my hanging plants as potential nest spots. It is like this thing is invisible. Oh well. I wish I could think of something else to do with it, it is pretty much useless.
