When those little fellers are hoovering the ground they are taking ground insects as well as the seeds we expect them to. The little seed eaters also scratch and scrape and much like chickens take a bite out of weeding with all that peckin'. Ground thrushes like robins are particularly adapted to human habitation as we provide them with the open areas they love to hunt insects in, and they do a wonderful job.
At our feeders we select by the foods we choose. When I was little, a cardinal was a rare treat. As America learned to feed black oil sunflower, we actually changed the range of this bird, not much seen above Maryland/Delaware in the 40's to mobs of them today. The same can be said for niger seed and goldfinches; I was in my teens before I saw one, now I see eight at the thistle bag with two hovering around... Mom saw an oriole at her new orange feeder today, and hummingbirds are more plentiful than ever now that so many folk feed them. We can help nature thrive.
We humans can support nature in amazing ways, and it invariably returns the favor. The fish eagles that were almost wiped out by DDT on the Lower Connecticut in the 60's are now drawing tourists to a festival celebrating them today. I hear examples like that all over the country as we finally begin to truly value our connections to nature. Yet we threaten bee populations despite the fact that they are responsible for about a third of the food we eat. We "control" and dam rivers, throttling the last life out it as we destroy the fish stocks that made it so vital. We are capricious in our choices of who lives and who dies and IMHO, we often get it wrong. Scarlet tanagers have become a rarity in much of the Northeast, both from the wholesale destruction of orchard owners shooting thousands in the early years of our country, and the loss of the deep wood habitat they love as we spread out. Fruit eating birds are not a good fit with our human system, and we dispose of the unwanted pest without any real knowledge of what that might do to the rest of the food web that tanager was in... it is still around I hear, but I haven't seen one in years. Not enough deep forest around here...
So please be gentle with your planet; it will return gentleness, or any other behaviors we show it. It is a system I have come to appreciate for its' complexity of function and simplicity of purpose:everything is linked to everything else, and all averything wants to do is come to a happy balance and live. We humans could learn a valuable lesson here; just try to be part of everything...
HG