Walking the line

Had lunch at Cecile and Heinrich and spotted this pair - mother and son? walking the line about 50 metres from where we sat on the stoep.
It seemed as if the Mom was getting impatient for the little one not following quick enough!
According to Cecile, the troop lives in the trees, displayed in this image, and roams freely to and fro looking for food, but it seems that there is enough water.
Jack,, this one is for you!