So I have more than one dog, who are free to roam around in a rather large area and they are often out of (my) sight. Usually one of the dogs hangs around the house (they seem to take turns on their own accord).
Each dog also recognizes that the other dogs have their own names. I think this is the case since when feeding them only the one I call out with each bowl of food comes up, and not the others, who wait for their turn (please correct me if I am wrong about this).
Is there a way I can teach them to go and call/bring (one/more of) the other dogs (for instance, the younger ones need to be given their medicine) so I don't have to walk the acreage on a mission of discovery?
The most obvious solution is a dog whistle. But there are other creatures around who are also sensitive to that (frequency of) sound and will respond to it. So whistling is not an option. I could also experiment different kinds of whistles (and I probably will), but that's not the point of the question.
I should add: they don't play fetch. Rather, they (each) played it exactly once. The second time I threw the ball they just looked at me and walked off. Neither am I interested in fetch, nor traditional schutzhound training. The dogs are very well behaved and "sensible", but not "highly trained".