I would wonder if it's actually for stick fighting? I agree it looks African but most of the stick fighting (at least in modern videos of events like the Suri of Ethiopia still practice) the sticks in use seem to be plain and not decorated. Of course this could just be the nice sticks aren't used in these events! However as Barry pointed out I think it is too short for the styles of African stick fighting I am familiar with, most of which require a whipping action, not a clubbing action. This looks fairly inflexible.
I think the pictures of the Hadendoa give a possible insight though, as I think I have rarely seen a cattle herder in an African context not leaning on a stick/staff of some sort. It seems just about the right size for that?
Unfortunately I don't recognize the decorative patterns.
But they don't strike me as being from in the Sahel regions so I think Tim is probably closer with the Zambia idea.
Cheers,
Iain