I've been enjoying the summer birds at the feeders, (the Rose Breasted Grosbeak is my favorite), but this summer I'm really having fun watching the Goldfinches as they master our new Bottoms Up™ feeder. They are quick learners and really don't seem to mind taking an inverted posture, although occasionally I'll see one that seems to be slightly puzzled by the perch/port arrangement, but not for long. The Chickadees haven't been left out of the equation and have rapidly adapted to spin around on the perch and reach below. So technically it is a Finch/Chickadee feeder. I don't have House Finches so I can't report on their lack of acrobatic ability. I welcome your observations and input.