When one of our 16 poults is out of sight of mother she immediately starts to call. One disappeared altogether today. She called the others to go for cover under a tree, located the missing one by calling it and responding to its subsequent cry. It had found a small gap in the boundary and was in deep undergrowth on the other side.Fortunately, we were around at the time and, with our help, it came back and peace was restored. It's left me wondering whether mother could count or detect quickly in some other way that one was missing before it called for her. This has happened several times on the land when one disappeared in long grass or a bush. Has anyone had similar experiences or can anyone suggest an explanation?