Bel, I looked, but I've only found a reference to cats grouping where they had been previously domesticated, and even then the reference implied that it was pretty rare. It appears that true feral cats will not do it at all. This pretty much conclusively shows (but doesn't prove) that nuture, in the form of domestication, somehow rewires cats' brains differently, perhaps to allow them to access instinctive behaviour which is never triggered in truly feral cats.
As for cats "talking", yes, your source is quite right. A study I read (in hard copy) a number of years ago suggested that the only times that a feral female will "talk" is when she is in season and when she has kittens. Or, obviously I guess, when fighting, and screaming is hardly dinnertable conversation is it? Our current moggy, Matilda, tries voices out on us and has us in fits. When she wants food she starts with the "come to me" trilling call that all cats seem to employ under those circumstances. It's the same one that mother cats use to round up their kittens. If that doesn't appear to be working fast enough, she uses a variety of calls in turn, making the call then sitting back with her head cocked to see if it has worked. she doesn't have the vocal repertoire of siamese cats, but she works hard with what she's got!
