I once saw what looked to be a blue bird attack a sparrow or some other small bird. There were many other birds around and the noise they made during the attack was extraordinary.
The blue bird ( or whatever type of bird it was ) ripped the head of the other bird but did not consume the bird. Just left the head and body laying where it fell.
Had never seen anything like that before.
Swans kill baby geese by breaking their necks or drowning them.
“I once saw what looked to be a blue bird attack a sparrow”
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If it was a house sparrow it had it coming. They kill bluebird eggs, nestlings, and even the adult bluebirds in the nest, and take over. But the bluebirds can fight back if they have an escape route - a two-entrance nestbox.