It happens every year in autumn in my yard and I suppose I should be used to it by now. A silence descends. The birds that flock to my feeding stations three seasons of the year suddenly desert me and all is quiet. No White-winged Doves crowd the platform feeders, no colorful Northern Cardinals fly to the post feeders or search the ground under them for their share of the black oil sunflower seeds. This year even the Northern Mockingbirds have abandoned my yard. I don't ever remember that happening before. If this had just happened yesterday, it wouldn't concern me so much, but it has been going on for weeks now. All of November was quiet in my yard, a silence broken only by the sound of leaves falling and squirrels squabbling. Though I understand why it happens, that doesn't make the silence any easier to bear. The birds disperse at the end of summer because food is plentiful in the wild then. It has been especially so this year. We have had an unusually heavy cro...