Isn't it fascinating to see science proving things we already know to be true? I mean, it's obvious that horses recognize each other by their calls. I've seen horses get more excited when they hear the calls of their best friends, when they may ignore calls of neutral herd members.
It kind of reminds me of that recent study that proved that coffee helps your concentration and can help improve test scores... Like I didn't know that already. Why else would I drink coffee? Haha.
Thank you for sharing though, it really is fascinating.