I was driving near Annapolis, Maryland this past weekend and I saw a large bird flying above me that looked quite distinctive. I was not able to get a photo, but if I had to guess, I would say it was about the size of a Red-tailed Hawk and was black , but could have just been a dark color. What really stood out was the tail. The tail was very long and at the end of it, attached the rest by a narrow strip was a small triangle. Not a fan shape, but a triangle. This is the second bird I've seen with this feature. Is anyone aware of any birds with this characteristic? I would appreciate any help and am eager to ID this bird. Thanks!