Building nests in the wrong places

Every spring, some bird builds a nest in the holly bush next to our front door. Sometimes more than one bird will do this. These nests are well-snuggled into the bush but very close to where we walk in and out, and to the place where we keep the hose and the rake. No baby birds have ever hatched and fledged within this bush. Indeed, so far as we can tell, no eggs have ever been laid in one of these nests. The birds complete the nests and then abandon them. One such nest was built and abandoned last weekend:

It has always seemed to me that the birds who build these nests might be be same ones who eat the holly berries later in the year. My theory has been that the bush looks ideal, full and quiet, in the pre-dawn hour of the day on which their instincts tell them to make a nest, so they do it. It is only when they finish constructing and sit down in it to rest that they realize how unprotected it is, how much we will disturb it even if we try not to do so. Then, I imagine, they quickly leave their mistake behind and find a new place.

My husband has a slightly different theory of what is going on with these birds. He says that the male bird builds it and then shows it to the female, who rejects it.

Shortly after the appearance of this year's empty nest in the front yard, we started to hear loud scrambling sounds and much tweeting and chirping in the roof of the back porch. I watched for awhile and learned that a bird was bringing twigs, grass, and polyethylene strings to a small open space between the porch roof and the house. It's the small, dark triangle near the center of this picture:

We first noticed this last Saturday morning. Thinking of the birds that regularly are not able to live in the bush because of our presence, we thought for a few hours that we might let them stay there and raise a bird family. We held that thought long enough for them to actually complete a nest, which (I hope) is dimly visible in this somewhat exposure-adjusted picture:
Then we watched as the male bird paused on top of the hot tub with another load of twigs in his beak. This is what he (predictably) did:
I had forgotten that, where there are birds, there is bird poop. And a closer look showed that, in just one morning of nest-building, a lot of guano had been deposited. So we (predictably) decided that the birds really couldn't stay there. We removed the nest and blocked the space with some asphalt tile. It was quite a nice little space for a small creature, and I am surprised that nothing has tried to live there before. Then we scrubbed away the droppings. The bird came back a few times over the next two days. The last time we saw it, it was salvaging the materials that we had dropped on the ground when we destroyed the first nest, carrying them away to some new, I hope safer, place.

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