It is not too late. Many Bluebirds are still searching for nesting cavities. However, it is not alright to put the box on a tree. Even if you haven't seen them, there are many things that will enter the box and eat the eggs or young. There are snakes, squirrels, raccoons, etc. Please visit the Sialis website to learn the proper kind of box, hole size, placement, and baffling options to ensure they have a safe place to nest.

Here is a link that might be useful: Sialis website

It is never to late to put up a nestbox but it is also never ok to put one on a tree or a fence. Boxes should be mounted on slick metal poles with predator baffles at least 15 feet away from fences or trees. Raccoons are everywhere, even if you don't see them. Like Kendra said, snakes, squirrels even cats can get into boxes mounted on fence posts or trees. Sialis.org is the best place to learn how to properly host bluebirds or other native cavity nesting birds.

OK, I guess I'll just be content with watching them as passerbys in my yard. Funny how many bluebird boxes I see around here on fence posts, and even in a state park nearby they are fixed on wood posts with no baffle or guard on them.

Hi, I have 3 nest boxes. Two on my fence and one on a tree. I live near a wooded area with a cleared section for homes. I have had multiple famiies in my boxes and the only predator I have encountered was a house wren who trashed the nest because it was too close to the woods. I would not be discourged about putting up a box on your fence. It is worth a try. The bluebirds really are looking for a home and if you see them in your yard, there is a good chance they will make a nest there. There are predators wherever the birds make their homes. It is always nice to help them out when you can. Good luck

mothraeve...you are so wrong. It is better to not put up birdhouses then to put poorly mounted houses which put the birds in danger. Houses should be mounted on slick metal poles with predator baffles. Why on earth would you want to put up a house just to have birds move in and then have the eggs or babies eaten????? Do you realize an incuating female is also in danger if a raccoon finds your houses? A raccoon can and will eat an incubating female bird if it raids the nest at the right time. You need to check out sialis.org for information on properly offering nestboxes. Just because you havn't had a problem yet doesn't mean it won't happen. In nature like it a natural cavity if a predator gets a bird, well that is nature. If it happens in a poorly mounted nestbox, that isn't nature, it is the fault of the person putting up the nestboxes. Just because lots of people put them up improperly and endanger the birds by doing so doesn't mean that you should give advice that it is ok to do this. It isn't ok to put birdhouses on trees of fences! You should take your boxes down if that is the way you think. Plus unless you actually monitor your nestboxes you would have no way of knowing if the nesting actually succeeded or not.

If you provide housing it is your responsibility to make it safe.