Aerial attack - interaction between two Tractrac Chats

Abstract

On a late June morning while driving on a farm road in the treeless gravel plains in Namibia (coordinates 22?25?S 15?24?E) I saw what looked like a Tractrac Chat cercomela (Emarginata) tractrac flying and repeatedly attacking something on the ground. At first I thought it might have struck down a snake or maybe a shrike on the ground, but it turned out to be another Tractrac Chat which was ducking every time another assault came down on it.