It's not exactly a zoo, but I'm wondering if anyone here has been to the VINS (Vermont Institute of Natural Science) Nature Center? It was one of my favorite places to visit in Vermont when I was a kid. I've always loved birds and due to Migratory Bird Treaty Act restrictions, most zoos don't bother with native birds other than game birds and birds of prey, and usually not all that many of either. VINS has a lot of raptors, as well as songbirds. I haven't been in a long, long time, so I don't recall exactly what they have (and since they're all unreleasable rehab birds it's likely to change), but I do recall it was always really fun to visit there.