The world is blessed with a huge number of birds classified into a seemingly endless number of varieties. This area, Southern California, doesn't appear to boast as great a variety as some other parts of the country nor do the birds here seem to be as colorful as birds elsewhere. Both of these phenomena, I suspect, are due at least partly to the relatively dry, desert-like, climate. Birds in more humid or tropical climes seem to develop more colorful plumage. Or maybe it's just that only the most dull among us tend to stay in one place.
Perhaps the largest birds we see on a daily basis are a species of crow known as California Ravens. They are large, typically two to four pounds, with shiny black feathers and a loud, almost mocking, "caw". They flock in groups of ten to fifty whenever food shows up somewhere. We throw edibles onto the front lawn just to watch the ravens. It can be occasionally dangerous just driving or walking down the street since the ravens use it to break open the shells of nuts from nearby trees. They will drop them from fifty or so feet overhead, presumably hoping they will break open or that an automobile will run over them to do the job. We have several who show up daily and 'caw' loudly to announce that they are ready to eat and they won't leave until they've been fed.
One day about two hundred or so showed up in front of our house. Flying in from every direction, they landed in trees, on the roof, on telephone and electric lines, and on the ground and yet with all that traffic not one bird crashed into another. It got me to thinking, do birds have a built-in radar which prevents such accidents or do birds indeed occasionally collide with each other? It would seem reasonable to surmise that a collision would occur from time to time. Sooner or later two or more birds would head for the same air space and collide.
Furthermore, when flying in opposite directions toward each other on which side do they pass? The right as we do on our roads? If so, what happens with birds living in say, France, who fly to England? Do they switch to pass on the opposite side from that to which they are accustomed? If so, at what point in crossing the English channel does the change occur and how do the birds know where that point is?
It would appear that we could learn a lot from observing the flying habits of birds. I am thinking of applying for a government grant to perform just such a study. This could easily become my retirement nest egg, so to speak.