The Northern Harrier can seem, for want of a better word, “easy.” Across much of North America, harriers are widespread and generally easy to find. And they’re easy to ID, with their distinctive shape, flight style, and white rump.
Harrier plumages are, I think it’s safe to say, widely believed to be straightforward. The juveniles have plain cinnamon-rufous underparts, the adult females are paler and brown-streaked below, and the adult males—“gray ghosts,” with inky black wing tips—are especially distinctive.
Left: Northern Harriers are “easy.” Could that lull us into complacency when it comes to field ID? Read on... Photo by © Jerry Liguori.
In a feature article in the March/April 2013 Birding, raptor experts Jerry Liguori and Brian Sullivan invite us to reconsider the matter of the supposedly easy adult males. First, they note that, if you get into the somewhat more technical literature, you learn of a brown–gray second-cycle male plumage that differs from the well-known after-second-cycle plumage shown by the “gray ghosts.” Then Liguori and Sullivan mix things up: By carefully analyzing digital photos of birds of known age, they show that some second-cycle males are "gray ghosts,” whereas some after-second-cycle males retain the brown–gray plumage traditionally believed to pertain second-cycle males.
Let’s back up a step here. The point, for me, isn’t to be able to age every after-hatch-cycle male Northern Harrier. The basic point runs deeper than that. The basic point is that we birders, myself very much included, have this stubborn and fascinating inclination to want to put birds in boxes. Our field guides tell us that birds look such-and-such a way, and our eyes and brains and minds comply. We see what the field guides show—three plumages of harriers—and that, as they say, is that.
Right: This is a male Northern Harrier. But do you know how old it is? You sure about that? Photo by © Jerry Liguori.
I’ve known about Liguori and Sullivan’s article for a couple of months now. (Yes, even in this age of texting and Twitter, it still takes a while to get from initial manuscript submission to publication.) And ever since, I’ve been looking anew at Northern Harriers. In the past couple of months, I’ve seen plenty of adult males, but eerily few textbook “gray ghosts.” Instead, I’m seeing gray–brown adult males, grayish-brown adult males, brownish-gray adult males, and so forth.
Once again, the real world is more complex, and more wonderful, than we had imagined. Thanks, Jerry! Thanks, Brian!
For a limited time, the ABA is making available for everyone a free PDF of Jerry Liguori and Brian Sullivan’s article, “Adult Male Northern Harriers: More Than Meets the Eye.” Click here to order the entire March/April 2013 issue. Or better yet, join the ABA today, and get the March/April 2013 issue, plus all the other benefits of ABA membership.
Be sure to visit Jerry Liguori’s raptor photography website.