The Hen Harrier Confusion:
Discussing the real Identification features

Gerry Dobler

Living not far from one of the biggest Hen Harrier winter roosts in Europe at Federsee in southern Germany, I always had a somewhat close relationship with that species. In the past, no-one really tried to sex and age the “Ringtail” Harriers, when the first proper counts were carried out from 1955.

By studying the best and most popular ID books I learned that juveniles are darker above, and show a prominent pale line along the tips of the greater coverts. In the books I read I couldn´t find any contradiction of this feature, and one of the authors even gave a nice side by side comparison, so separating out the juveniles using these features seemed like a good plan. So I went to the Harrier roost which, during that winter, was located in front of a wooden watch tower, from where we could look down on the flying Harriers.

I saw many Ringtails but didn’t get very good views and then finally I found a juvenile bird with the comparatively dark upper-side and an obvious line along the tips of the greater coverts, as described in the book. While watching this bird I had the impression several times that it had yellow eyes, which I didn´t fit with the information for juveniles in many ID books. But at home I found, in the most popular raptor ID book, a note that juvenile male Harriers could be separated from their sisters by their yellow eyes. Obviously my Harrier was a juvenile male and I wanted to confirm that as soon as possible.

I arrived at the watch tower early in the afternoon, and when my bird came back to the roost in the evening I easily confirmed it had yellow eyes, making me proud about my first properly identified juvenile male Hen Harrier, at least for a couple of minutes. As the bird dropped down into the reeds I clearly saw it chase a grey 2nd winter adult male away, and when that bird took off, right beside of my bird, I recognized that my bird was much bigger and broader winged than the older male!

My hopes of having discovered the ‘Pygmy harrier’ as a new species faded soon and I was deeply unsettled, finding myself again back in the middle of the books later this evening. As my attempts in solving the problem top-down had obviously failed, I eventually decided to switch to the bottom-up method, by searching for “darker under-secondaries” and those “rufous-yellow”, “ochre-coloured” or “rusty-buff “ underparts of the body, stated being distinctive for juveniles.

I felt in need of better light too, and therefore went to the Harrier feeding areas out in the fields. It didn´t take long to find that typical bird displaying the right features in the middle of a vast meadow. I watched this individual for at least half an hour using my scope. To my surprise I saw it too had yellow eyes again, which certainly didn´t fit to most of the descriptions. But I remembered that the special raptor book stated juvenile males have yellow eyes and I ultimately identified the bird as one of these. After some minutes my bird took off and started chasing another ringtail Hen Harrier that was obviously carrying a vole. In that half of a minute of ‘harrying’, before the victim dropped its prey, it was clear that my bird was much bigger than the chased individual, and the latter was much paler, almost white, underneath.

A little weak adult female chased by a huge juvenile male didn´t make any sense at all to me, so by this time I was mentally pretty devastated and confused. I came to the conclusion that somebody had to start from zero to solve this obviously very complicated topic.

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