I have recently been aware that a number of small birds have been chasing off some much larger ones.
I know birds protect their territory and especially chase off the likes of sparrow hawks and kestrals but recently I have seen thrushes chasing, at speed, woodpigions across some great distances. Also seen blackbirds doing the same.
The thrushes seem to be very persistant in their chase, not giving up quickly but really chasing the woodpigions some distance out of the area. Same with the blackbirds both male and famale.
I've sen this kind of thing happening as I say with the preditory birds but never with the woodpigions. They really don't like it!
Have fun and enjoy the world you live in!