There's no getting around it JLB. John saw something, and it looked like a dove. If he didn't see a dove, then what did he see?
Matthew 3:16
And when Jesus was baptized, he went up immediately from the water, and behold, the heavens were opened and he saw the Spirit of God descending like a
dove, and alighting on him;
Luke 3:22
and the Holy Spirit descended upon him in bodily form, as a
dove, and a voice came from heaven, “Thou art my beloved Son; with thee I am well pleased.” RSV
John 1:32
And John bore witness, “I saw the Spirit descend as a
dove from heaven, and it remained on him.