Monday 21 April 2014

Northern Harrier: the flounderer's account

'Reidentified from photos' is one of those phrases which makes good birders roll their eyes in pity at the clueless halfwit who has the good fortune to stumble across a quality bird and not know what it is. Serendipity and digital cameras have combined to make this an increasingly frequent phenomenon, and today, blessed with the benefit of both, I became that halfwit.
Rufous spotting on the underside visible in this shot
My Swineham patch had been a complete, well, swine last week, turning up a frisky pair of Stilts the minute my back was turned, so still piqued with it this morning, I headed off early to Portland instead. In your face, Swineham. A fistful of Wheatears, a Whinchat and a flyover Yellow Wag enlivened Barleycrates Lane, and having walked Reap Lane and compared notes with Pete Coe, I doubled back on myself to catch out those sneaky rarities which I surmised had been pulling faces and flicking v-signs behind my back on the way down. I was a good way down the Lane from the seaward end when I looked back and saw a large pale bird flying purposefully north in the distance, which I suspected was a Harrier. Views through bins appeared to confirm a male Hen Harrier but it was too far away to be completely sure to species level so I hoisted the lens for some record shots. The bottom photo is the original size which gives some idea of the distance involved, and while the back of the camera shots were still very small they cropped up surprisingly well.
Less black in the outer primaries than Hen Harrier
We see Hen Harriers through the winter in Poole Harbour so I didn't think it that remarkable, though on arrival at the Obs and telling others about it, it seemed that Hen Harrier may be rarer than I realised on Portland. The Warden Martin Cade said he would appreciate even a poor Hen Harrier shot for the website so I happily obliged when I got home. Shortly after the phone rang and it was Martin asking if I had considered Northern Harrier, the American subspecies of Hen Harrier. In all honesty, I hadn't. I had noticed some apparent rufous markings on the underside in some shots, but having ruled our Monty's, I put this down to it being a not quite adult male. Martin had additionally noted the darkness of the hood, and the more limited extent of black in the primaries. The former I had dismissed as a trick of the light, the latter I just hadn't studied hard enough having concluded it was obviously not the black wedge of a Pallid.
The Harrier just kept going north and never looked back
I was then tied up with family duties for the afternoon and had to leave it to the experts to ponder further - Martin contacted Martin Garner who shared the view that it was a Northern Harrier, the news went out and my pager buzzed with a message to that effect as I tucked into ham, egg and chips at the Bankes's Arms. Brett Spencer had come to the same conclusion on seeing the photos independently so that's three opinions I'm not going to argue with. Now I'm feeling sort of pleased at playing a part in turning up a potential first for Dorset, but sort of a tube for not realising it at the time, and bad that no-one else seems to have seen it subsequently. In my defence I have no experience of Northern Harrier here or anywhere else, and a memory like a sieve, so even if I had it might not have helped. After I put the phone down to Martin, I googled a Birding Frontiers blog post about a Northern Harrier in Cornwall and had a moment of recognition like Dory in the film Finding Nemo, which any parents out there are sure to be familiar with. If not, see here: http://www.youtube.com/watch?v=nDpqi_6UHGk. Suddenly it all came flooding back.
The best I could manage of the uppertail which is dark-tipped in Northern Harrier - click to enlarge
So, a very big thanks to Martins Cade (for the initial identification) and Garner (for the confirmation) for shedding all this light. Without Martin's request for a record shot there might have been nothing to be reidentified as even by the low photographic standards of this blog I might never have posted those grainy shots. No complaints, then, just a request: can I have an easier one next time please?
The original, back of the camera shot. Where would we be without digital photography? (Ed: still ignorant in my case, but with even less capacity for learning).

3 comments:

  1. Great write up to a cracking find. Well done buddy.

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  2. Very interesting. On Tuesday morning we were driving down the steep hill just west of Abbotsbury when a raptor flew across in front of us and then back again, very quickly .We only saw its back which was pale brown with crescent shaped wings, larger than a sparrowhawk but smaller than a buzzard. Might this have been a female Hen Harrier? Are they known in the area? Stopped within a hundred yards but no further sign!

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    1. Hmm, a big female Sparrowhawk would still be my best guess. Then again I think my post above suggests you shouldn't take much notice of my views on raptor ID, even if I've seen it! Kind regards, Peter

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