The new feeder is suspended from ant guards and should be critter-proof.
When I got down to the oasis (from the house a block away) shortly after daylight today the ground feeder had been emptied (I suspect coons or ringtails) and I heard the distraught thrush scolding back in the arroyo. I hurriedly put a few grapes in the old feeder. It wasted no time gobbling them up. My hope is that when that feeder gets empty, he'll look around and find the hanging feeder. But I've learned not to make assumptions, so I'll probably put out grapes in the ground feeder until I'm sure he's discovered the other one. I almost got a decent photo of him grabbing a grape this morning.