Just asking but would he be able to identify that they were pigeons given the sheer terror of the moment? Maybe just birds?
Very nice image. I could see myself being scared shitless of a cloud when all my senses are in hyper-sensitivity and I'm being confronted by an unreasonable situation that I am rapidly filling up with fear by the moment.
This is kind of a philosophical thought and while interesting, it's taking us out of the suspense of the moment. What is he going to do when faced with the (sudden?) removal of the entire human race, at least where he is? That reality has to press in on the reader like the heat going up rapidly in a small room without windows. Cook us a little more before the philosophy drops.
Nice pull back to the humanity of his situation. This is a measuring cup of suffering and a scale to weigh emotional loss. Come back here often to set the value of how much he suffers.