We have a hopper feeder for the birds. They don't always like to share it. So on a warm day, it's one sparrow per side, front and back, who will throw a gigantic hissyfit if another bird lands on the feeder.
When it starts to get cold, two sparrows will share the same feeding ledge, at far corners, with an occasional peck and flutter. They will also cooperate to drive off anything that tries to land between them.
On a cold day, three sparrows will land on the ledge, but they squabble back and forth.
You know it is really frigid out when there are four sparrows crammed wing-to-wing on each side of the feeder, all stuffing their faces as fast as they can, instead of fighting.
Also out today were a few mourning doves and a pair of cardinals.