Bird behaviour

My neighbour's TV aerial usually has a bird of some kind perched on it. This morning there was a tussle between a collared dove and a magpie for occupation! I would usually have put my money on the magpie but the dove had other ideas. Every time the magpie came close, the dove chased it off until eventually it gave up and retreated. I think the doves are keeping an eye on fledglings as they're very active at present so it may be that it saw the magpie as a threat to its young one.