This bird appears to be black in color, or at least very dark. It has a hawks bill used for snatching little hatchlings right out from underneath the mother. It feeds off of another seabird, although I do not believe it is a seagull. Hunts very fast, so that before the mother knows whats happening, it has made off with her baby. I saw this on the Animal Planet during the airing of one their “Most Extreme” episodes. Any idea?