There should be proper walls so you can see what it is and they should have ledges where we can sit and rest before for the next flight, but also build stable homes.
Even those of us who specialize in fish has recently discovered cities. There are ready made nests in several locations. (see picture below)
More and more of us who are not so common has also discovered the cities so perhaps we will become more common in the future. Then we would recommend architects to consider include frescoed design. Plantings and grass roof with flowers that are inviting to insects and then we need not always to fly down to the ground for food.
We have also discovered that life in the city is more hectic, so we have to sing louder and faster and we can do that, no problem, and sometimes we are so many together that we can even drown the noise from the traffic. Our relatives out of town, yokels sing so slowly and more quietly.
Then there are not so many birds of prey, another plus with the city. Maybe, they will also discover the benefits of the city and increasing as time flies by.
Another advantage of the city is that it is warmer than the surrounding areas so you do not always need fly south and then we have time to add more kids and like many people who want to hear us sing. In several cities, we are now more birds than people. But unfortunately even cats like that there are more birds. You see the cats, this misery to the four-legged creatures that people prsists to view as a cuddly toy. They are our worst enemies in the city especially in the suburbs,but even rats and other wood climbing beast as the American possum, Virginia opossum. If people just keep there numbers low we will multiply and sing more. In many residential gardens we are invited to food with free housing and we never say no. And you, when working on your home leave some little tiles on one side so we can more easily come in and simply drag both grass and tufts of hair to make a comfortable place fo our toung ones.
So keep planting flowers and trees between the houses and keep after your cats and why not even keep them in the ´rope that you do with your dogs then we will really multiply us. "