Owls are fascinating creatures. We hear them at night, and we know they're not far away. But we hardly ever see them. In fact, they are splendid living machines, designed to catch prey. Somebody said that you might describe an owl as a big pair of claws with wings.
This is a fine specimen of marvelous owl images that I found on Jerry Coyne's blog [access] titled Why Evolution is True.
This BBC video provides a highly didactic account of why owls are such expert killers: