Swainson's Hawks will start to fledge soon so I thought I would share a little tip on one aspect of ageing them in flight. Of course there are other ways to age Swainson's Hawks, but this is just a note to share. Check out the contrast between the dark flight feathers and the pale body on the adult (left) versus the juvenile (right). Light adults have a much higher contrast to the underside (due in part to their darker flight feathers) than juveniles and this is a good mark to look for on distant birds. Also, adults have a dark tail tip and full "bib." Beware of one thing...although uncommon, some juveniles look bibbed similar to adults. Note the juvenile's fresh buffy plumage they show when recently out of the nest.