Did a real, physical dove appear at the Baptism of Jesus, or is this just metaphorical language (maybe a symbol found at various places in the Scriptures?)? Maybe someone could shed light on this.
There was no dove at the baptism of Jesus. Read the scripture a bit more closely and you see that:
It was the Holy Spirit which came down like a dove.
Just to add to Flimzy's excellent answer. There are several instances in the Bible where the Holy Spirit is seen in a physical form.
All Scripture is quoted from the King James translation, unless otherwise noted.
Once in the Old Testament he is seen as a hand writing on the wall.
And also in the New Testament;
With these and other Biblical accounts of the Holy Spirit appearing in a physical form it is not so strange or even mystical that John should have seen the Holy Spirit in some physical form descending on Jesus like a dove.
We can try not to analyse too much. It is physically a dove but also mythically or spiritually, the Spirit descending economically on the Lord for His ministry.