[midoridensha]

>ear-clipping isn't foolproof though, since many feral cats will not sit still long enough or let you get close enough for you to observe a clipped ear.

Nothing is foolproof, but you can use binoculars to see feral cats' ears from a distance if you really have to. Most stray cats, in my experience, are NOT friendly at all; they won't let you come close enough to them to pick them up, and if you do they might fight you.