Are ravens dangerous?

[Pisciottano]

Hi anyone,
My 36 days old pigeon, who had been born on my balcony, flew away some 5 days ago. I've seen him all by himself on the roof of nearby buildings with ravens flying around him. The never attacked him to my knowledge but I've done quite a bit of worrying about it. Actually, his mother joined him today so that I don't think I need worrying about it anymore but, just for my education I'd like to know if he were ever in danger. Does anybody know anything about ravens? Thanks for listening. Gladys