In regards to Harrier eye color and plumages, I was asked about juveniles, so I thought I'd put up some pics to show the differences. First of all, it has been proposed or talked about for years that juvenile males and females have a slight difference in plumage, but for the most part this is not true. The plumages overlap greatly; there might be a slight difference on average, but it is unreliable to sex juveniles based on body plumage alone. I won't even say what those differences could be, because it would be misleading more than helpful to the birding community, and too often I hear field marks perpetuated that are absolutely false (another post I should write). Here is a link to the post I am referring: 

http://jerryliguori.blogspot.com/2013/10/juvenile-harrier-color.html

Anyway, juvenile males have yellowish eyes, and juvenile females have brown eyes. Sometimes, juvenile males show a bluish-yellow eye, or even brownish-yellow. Hawk banders know this stuff. Here are some examples below that will help you identify photos of juveniles, of course, noting eye color in the field can be extremely difficult. And remember, fairly streaked juvenile males with yellow eyes can be confused for adult females, so check your photos!

  Juvenile Female

Juvenile Female

  Juvenile Male

  Juvenile Male