Where did my feeder birds go? An answer based on actual data.

So many back yard feeders are still bustling with activity, especially for those of us offering suet but, generally speaking, average feeder activity is finally (although regrettably) starting to slow down. For about three weeks now, we hear the question daily: "Where did my feeder birds go?"
Well, there's a real answer to this question and it can be substantiated with science. Rather than just go on and on with a written explanation of where your feeder birds went, I thought I'd try to actually show you what's going on.
You can study feeder birds this way no matter where you live. If the birds I've chosen for this study don't apply to your avifauna then you just have to generate a different subset of birds to study. You will also need to consider that breeding season hits its peak later in most of the rest of North America than it does in Florida.