Raptors
I include in this category eagles, owls, hacks, falcons and vultures. Except for vultures I more often encounter these types of birds in captivity then in the wild. For this reason I like to go to raptors rehabilitation centers and places like that. I see them often while driving but it's not a good idea to click and drive. Some of them like the snowy owl are a project still remaining to concretise, so far every time I went on an expedition to photograph them I came back empty.