On April 25, the four fledglings from the first brood had flown up into the trees and for the next two weeks or so would be fed by their parents, primarily the male. I did not catch a single glimpse of any of them during this time.
After the fledging event, I had taken the nest box from the pole for cleaning. I removed the nest — using a plastic bag so my hands would not touch it, and carefully so as to not stir up dust particles to breathe in — tied the bag and disposed of it. A narrow wooden dowel works well to help lift the nest up from the bottom of the box. I then cleaned the inside of the box using a nylon bristle brush and a solution of water and white vinegar. I then let the box air dry in the sun and remounted it to the top of the pole.
Some personal tips: For subsequent cleanings after future fledgings I’ve used water-based solutions of bleach and dish detergent. The white fecal residue on the inside walls of the box cleans off rather easily. Whatever you select, make sure it’s a mild cleaner that naturally breaks down quickly and doesn’t leave a residue. I would also advise labeling the dowel, the solution mixing container and the brush so they don’t accidentally get used for another purpose. It’s best to handle everything with care to lessen the possibility of transmitting any type of avian disease.
My nest box is positioned in my back yard so that I can easily see it when I glance out the glass door to the back deck. There’s no telling how many times I had looked out at the nest box during the previous brood, especially when the parents were busy making feeding runs. Each glance of this activity would bring a quick smile.
In addition to the sheer enjoyment, I also was looking out for predators. On a couple of occasions during the first brood I saw a snake approaching and removed the threat before it could do any harm. The pole I had used for the first brood didn’t have a predator guard attached and, at the time, I did not understand the importance of having one. I also figured that since I was looking out at the nest box frequently throughout the day that I could act as an effective predator deterrent. I would soon regret thinking that was sufficient.
For the next two weeks, my glances out at the nest box didn’t yield smiles, just disappointment. There was no activity at all, and I was beginning to wonder if my backyard bluebird nesting event had just been a one-time occurrence. Would they return for a second brood?
Twenty days after fledging, on May 11, dad returned to the nest box by himself to inspect it. Two days later, both the male and female were inspecting the nest and displaying courtship activities. Nest building began the next day and was completed by May 17.
On May 19 the first egg was laid. There was indeed going to be a second brood! In the following days three more eggs were laid, bringing the clutch size to four. For the next two weeks I monitored the next box daily and all eggs appeared intact.
The nest was completed by May 17.
On June 5 two eggs had hatched; the third hatched the next day. The fourth egg was not viable, so this brood was three chicks. All went well for the next four days as I would monitor the nest box and also look out for predators.
On June 9, I became engaged in watching a college baseball game on television for a good portion of the afternoon — and not glancing out at the nest box as frequently as I normally did. Around 6:30 p.m. I looked out to see the male bluebird perched on the side of the nest box, not on the top like usual. Looking outward, he remained there virtually motionless for quite a while. I suspected something was wrong but didn’t know what.
The next morning at 8 a.m. I checked the nest box and found a devastating sight: all three chicks were gone and only the unhatched egg remained. Obviously the work of a predator, likely a snake. Neither parent came by for the rest of the day. The following day, the male visited the nest box very briefly, almost as if to fully convince himself that the brood was gone.
This was the heartbreaking lesson about the need for a predator guard. I vowed that I would do everything practicable to try and prevent this from happening in the future. I found instructions on how to build a predator guard. I added an additional motion detector. Since snakes don’t give off heat to set off a motion detector, I ordered some wireless video cameras that I could activate and view during the night. Maybe, by chance, I could visually see an approaching snake.
I cleaned the nest box and returned it to the pole, hoping the parents would try for a third brood. There was no activity. So, on July 27, I removed the nest box and pole from my back yard.
As I waited five months for the start of the next nesting season, I wondered if the bluebirds would ever give my back yard — and me — another chance.
– – –
This is the fifth column in a series.
Next in the series: “The First Brood of 2020: The Bluebirds Return For a New Year”
Leave a Reply