1. I've been informed by the ebird reviewer and by another helpful cbirds correspondent that the swans in the picture were not trumpeter swans. I hope I didn't lead anyone on a wild goose chase. Both these species would be first sightings personally for me.
2. The recording was thought to be tundra swans too. Evidently single or just a few birds can make a very different noise than those in large flocks who are more excited.
3. Pungo is still an awesome place to go--its called an "inviolate" waterfowl sanctuary, which means no hunting ever by anyone anywhere within the unit. So access is more difficult for birders but there's lots to see.
P.S. Regarding Nathan Dias' description of "jump shooting" activities: on the only day I went to Kerr Scott Reservoir during active duck hunting(inadvertently), I witnessed exactly this behavior, with the result that several gulls and grebes were shot and injured in addition to the targeted ducks. I have to assume it happens quite often, which is pretty disgusting. Thanks to Nathan for helping expose this situation.