Week of the Disappearing Eggs

Post contributed by Sharon, volunteer bluebird trail monitor:

Five bluebirds hatched recently. There were no new fledgings or eggs laid in the past week.

Gorgeous tall grass prairie in bloom,
site of Gilbertson nest box occupied by bluebirds

Unfortunately, there has been a reduction in the number of bluebird eggs on the trail. Four bluebird eggs disappeared without a trace from one box—the nest inside was completely undisturbed and clean. It could be the work of house wrens, though the box is not located near a brushy area (typical house wren habitat).

There are still eight bluebird eggs in two other boxes.

The last tree swallow nest filled with feathers turned out to be empty—no eggs, no birds, no mess—used tree swallow nests end up very messy by the time the young birds fledge. There definitely were eggs in there earlier, but they never hatched—this nest was pristinely clean. The phantom yellow beak in the photograph from two weeks ago must have been the thick blade of yellow grass I discovered when I removed the empty nest. What happened? Perhaps house wrens removed these eggs, too.

Eight boxes are now unoccupied.