Do male Eastern Bluebirds ever successfully hatch the eggs?

In one of our boxes, we had four eggs with no sight of the mama. After several days, a male has started sitting on the eggs. Is this just wishful thinking on his part, or might a male actually hatch the eggs?

Unlikely to succeed, but not impossible. If you keep a good supply of mealworms handy so he can grab a quick bite to eat without being away from the eggs for long, it'll help a lot.

Resin

Thanks for the reply! I didn't feel that this was natural behavior. Doesn't the female have a special spot on her breast to keep the eggs warm? Too, the eggs sat unattended for at least a week before the male started sitting on them. I do put mealworms out early morning and late afternoon. We have a chickadee with one baby and another bluebird box with five babies.

The males of most songbirds also have a brood patch - they will usually do some spells on the nest, and need it for that.

If the eggs were unattended for a week, that isn't good news. Don't get your hopes up!

Resin

Do you know for sure he is sitting on them and not just checking on them or guarding them? Do you have a nest cam?


I don't consider myself an expert but I do participate in several forums that specialize in bluebirds and for five years I have hosted bluebirds in my yard. I observe their behavior every day.

With Eastern bluebirds there are very defined roles between the sexes. For example, I have never heard of a male bluebird building a nest or incubating the eggs. I have never seen even a picture of a male bluebird with a brooding patch. Loss of a mate during nesting, on the other hand, is quite common, and can result from many diffierent things, such as her being taken by a preditor or killed by a house sparrow, or being hit by a car, or as twice in my case, arrival of a new female that fought with and drove the sitting female away. That last possibility is not likely in your case since you are not seeing any female around.

I agree with Resin that with birds many things are possible, but it is an extremely long shot. My guess is that the male likes the real estate and while looking for a mate he is protecting his interest in the nest box. When a new female shows up, be ready to remove the old nest. Otherwise she will remove or simply build on top of the eggs.

Dave