Without knowing the person's situation, or the hows and whys of what he's doing, I can't really suggest what you should do. And unless I had the means to actually help (maybe some extra pet taxi's to give him to set by each of the birds?) I wouldn't go over and put my nose in. Unless they are OBVIOUSLY injured, neglected or in imminent danger I woudln't call animal control.
It's probably not the popular choice, but it's what I'd do, and here's why.
I had my cage birds sitting on my front porch, i usually do that when cleaning their cages. But I had a bad spider problem and was bug bombing the room the birds are usually in. It was a lovely day, my porch is secluded, and partially screened in. I worried that the chemicals would leech into the rest of the house harming the cockatiel and parakeets if i left them inside. I made sure the cages were secure and needed to run to the store for some new feed for them (i had forgotten it and left it in the room i was bug bombing). I didn't want to make them sick with contaminated food. So I went. By the time i got back, about 30 minutes, animal control was here and I was cited for neglect. My birds were squalking away enjoying the outside fresh air. Someone decided I was just leaving them out there and not tending to them. I showed the officer I went to get new food, and showed him their usual inside environment. To my luck I also got to show him a few dead black widows, thanks to the effects of the bug bomb. You could smell the chemical in the house when you opened the door, i got out of the ticket, but it was embarassing and totally unnecessary. They had no idea what my reasons were and jumped to the worst possible conclusion and nearly dragged me over the coals.
