To say that Swallow is greased lightening in flight is to say the obvious. He has to be fast and quick on his wings because he feeds primarily on flying insects. As the scientists say he is "insectivorous." Watch the speed with which this little bundle of energy zooms through the air and then realize that he is not just catching any old bug that happens to be up in the air at the time. Swallow is selecting the ones that he wants and evading the ones that might cause harm if eaten. You won't find Swallow swallowing a hornet for instance.
Swallow has been around for a long time in most of the world that is not perpetually covered in ice and folks have noticed him. He is in the Egyptian hieroglyphics, where he is associated with the souls of the dead. Back in the day, when men were made of iron and their ships were made of wood, seamen were fond of tattoos depicting Swallow - the thought being that he always returned home (a la the swallows of Capistrano). Here too, in Sea Ranch, Swallow always comes home and is a welcome harbinger of Spring.