The galahs were being pretty bossy and not letting the pigeons in. After this shot three cockatoos landed on one branch and broke it so it called for a new dead-tree feeder. Luckily we had another part of the same dead tree to replace it.
The pigeons are by no means defenceless in these skirmishes and it looks like the pigeon is engaging in his own form of attack, whacking the galah over the head with its wing. They do it so quickly and you managed to catch it mid stroke.
