QUESTION: We had a pair of bluebirds nest in the box in our backyard, and produced 4 babies. I checked on them regularly, and things were going well until about 2 weeks after they hatched. I noticed that one of the babies was not moving, and the others did not respond when I opened the box to check on them. They were still breathing, but did not try to "feed" as they usually did. Today, I opened the box and realized that there was one fledgling who had died on top of another who was more decomposed. The "top" baby already had put out its blue feathers, so it was ready to fledge....Can you give me an idea about what might have happened? This is the first time this has happened over the several years we have had this box.
ANSWER: Unfortunately this happens sometimes. A predator gets one or both of the adults and the babies starve. They have many predators, and although sometimes this upsets us it is part of natures plan. One Bluebird pair can raise 15 or more young in a season, and if yhey all survived we would be up to our hips in Bluebirds and they would be running out of food. Predators usually get the sick, the slow and the dumb, thus keeping the species strong. If you will send your mailing address to me at email@example.com I will send you my free Bluebird book that will make you an expert. Good luck, Bluebird Bob Walshaw. PS - See page 19 for why you should have more than one box.
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QUESTION: I failed to mention that both parents were very diligent in coming to the box to feed the babies, when I suspect at least one was already dead..... I think the mother was unable to figure out how to get the deceased one out of the box...., but she and the male continued to fly in and out of the box.
That is odd. Usually the situation is how I outlined. We do find dead young in boxes after the others have fledged with no explanation. Sometimes a baby will choke on a too big insect. Also if there has been some pesticide spraying in the area insect food can be contaminated. And sometimes we just don't know. Don't forget to send for your free bluebird book - mailing address to me at firstname.lastname@example.org