I’ve seen an Eastern Bluebird (Sialia sialis) flying around the nest box which is near our house, so I knew it was time to get out and start this year’s nest box trail checks.

We lost one of our nest boxes last year in the great Halloween flood. The fence post it was attached to was in the path of 4 feet of rushing water. Only the back of the box was left and that was gone when the fence was repaired. We’ve yet to replace it, so the hike today consisted of 7 nest boxes.

Our nest box trail wraps around our property and each box is mounted on a fence post which we installed or was part of an existing fence. The nest boxes have to be a few hundred feet apart because the bluebirds are territorial and won’t use the boxes if they are too close together. We also try to place them on an edge, between grassland and woods, and with the opening facing south. We have no control over what species of bird will use the boxes, so we try to maximize our chances by making them as attractive as possible.

Out of our 7 nest boxes, only 2 were empty. One of these looked like it might have the start of a nest in it, but I don’t count it.

Of the 5 boxes with nests, 3 had bluebird nests in them and 2 had what appeared to be wren nests.

Here’s a bluebird nest. It’s made of thin grass stems and is fairly tall and deep. This one has three eggs in it. The eggs are a pretty blue color and about 1/2 an inch long.

Here are the eggs in this nest. The bluebird may lay a few more. Clutches of 5 or 6 eggs are common.

Here are two eggs in another nest box.

This is one of the nests which I think might be built by a wren. You can instantly tell it’s a different construction than the bluebird nests. This bird likes to use thicker, small tree twigs, and even white pieces of fluffy material.