There used to be so many wild budgies that when the flocks found water in a drought - usually a farmer's waterhole for cattle - they used to drown by so many when going down to drink, that frequently the farmer would have to net a full truckload of drowned budgies to clean the water for drinking. Honest.
They have settled down in numbers but as Tbird said, they are still around in HUGE flocks.
The wild buderigar is a little fellow barely 6 inches and nothing like the domesticated ones.