I think if you look for intelligence and awareness in any animal you'll find it. I have fish in my goldfish pond that know me from other people. Anyone can go stand on the edge of the pond, but when I approach, they swarm- I'm the feeder. I look very similar to my daughters, my sisters, and a friend, but apparently height, hair color and body shape aren't the discriminating factors. They know somehow.
My birds know me, and the roos have always used specific sounds to notify the girls of who is approaching. Big dog (Henry) gets clucks at a certain pitch in 6 quick pops. Little dog (Daisy) gets 3 quick ones and then a 4th at a lower note. Hubby is a high pitched longer note and then 2 more, descending with each.
Neighbor dogs are all allotted a high pitched series of 3, then a lower series of 3, but it's different if a dog they don't know goes past- it's a lower series of pops to get everyone's attention, like, "Wait...ready to run!!" We have a very busy street and lots of foot traffic goes through visible to their yard.
I'm not sure if the new guy in charge has similar calls and notifiers. I've only had him here a week and Professor had been the head honcho for years. It would be very interesting if the noises were the same despite the boys never having met. What would that mean?
You might think me nuts for having observed all of this, but I write a lot and love to sit out in the yard with them...if I can keep them out of my lap while writing! Often have one on my head and put my feet up so they can stand all down my legs. Thank God they all know not to poop on me. We have a deal.