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Re: Mystery bird of prey?

Posted: Mon Sep 02, 2019 6:59 am
by RussCannings
While I'm not experienced with the full range of Male-type plumage in either species, comparing this amazing-looking bird to photos of Eastern Marsh Harrer, I feel like a male EMH of this age would have a completely unmarked tail, more extensive black (not barring) on the underside of the outer primaries, and a less conspicuous dark trailing edge to secondaries. I also wonder how much of the cold colour tones are a fragment of the lighting? The closest shot of the bird shows warm brown steaking on the chest and neck, more of a Australasian thing.

For me, I see so few old male NZ harriers in the field, they always make me double take. It seems photographers would probably agree as there are very very few shots of the really grayish ones online. The Australian Bird Guide has the following warning in their account on (Aus) Swamp Harrier: "...Beware oldest palest (males) in which head, upperparts, and upperwing-coverts are near black."

Maybe this is just the manliest swamp harrier we've ever seen?

Re: Mystery bird of prey?

Posted: Mon Sep 02, 2019 7:14 am
by Steve Wood
Hi Russ, thanks for your comments and I did see the Aussie field guide reference to the paler older birds and most of us are a where of them.
However, I cant help but wander if you were any where else other than Australasia and saw this bird would you call Swamp Harrier?

Re: Mystery bird of prey?

Posted: Mon Sep 02, 2019 8:47 am
by RussCannings
Probably right Steve. If I was on holiday in China and saw this bird, I'd almost certainly let it cruise on by (doesn't help that I'm not much of a photographer either). That's partly due to my field inexperience with Marsh, but also how damn similar these birds are! If I saw this bird in Canada, it would be another story.

In NZ especially, I think we (speaking for myself at least) can all be guilty of taking raptor ID for granted when there's generally only one option (I'm discounting falcon here). I'm not saying this isn't a Marsh (I'm certianly not qualified to make a yes/no 1000% determination, just provide armchair assessments), but as per usual Mr Occam (or Ockham!) requires us to first remove the obvious. This probably means we let a few legitimate vagrants slip through our cautious hands, but at least in this case you have stuck with the bird and now we have something to work with and properly scrutinize and learn from.


Re: Mystery bird of prey?

Posted: Mon Sep 02, 2019 10:58 am
by Steve Wood
Couldn’t agree more - my first impressions as I stated,was, - Ah, just another pale swampy !
However I think this bird deserves a closer scrutiny as its similarity to EMH is un canny.
Ps. Big fan of Mr Occam.

Re: Mystery bird of prey?

Posted: Mon Sep 02, 2019 11:15 am
by Paul Sagar
It's usually referred to as Occam's razor; named, if my memory is correct, after the Franciscan friar William, who happened to live in Ockham at the time.

Re: Mystery bird of prey?

Posted: Mon Sep 02, 2019 11:25 am
by Jim Kirker
This bird was hunting over Waiatarua wetland on 25 August this year. The poor photo I took shows a much paler head than the bird in Steve Wood's photos. I guess this could be an artefact, but the difference looks real to me. It would be hard to accept the Waiatarua bird as anything but an old NZ marsh harrier, so maybe the head colour is variable or the difference (if real) supports the possibility that the Nelson bird is another species.

Re: Mystery bird of prey?

Posted: Mon Sep 02, 2019 12:14 pm
by Tim Barnard
It is an interesting bird. Like many, I have seen some very pale AHs but what intrigues me about Steve's bird is the darkness of the head and the fact that the streaking is quite restricted to the upper breast ... forming almost a band. And has been commented above, the almost complete lack of any warm tones ... certainly has a passing resemblance to EMH.

Re: Mystery bird of prey?

Posted: Mon Sep 02, 2019 12:55 pm
by RussCannings
Definitely worth sending pics to hawk-watchers in Asia. Nothing to lose and a lot to gain.

Re: Mystery bird of prey?

Posted: Mon Sep 02, 2019 2:25 pm
by sav
Hi all,

At the risk of being a complete killjoy......

I spent some time this morning looking (again) for this bird, mostly because it looks stunning, but aren't we getting a little fanciful with talk of Eastern Marsh Harrier?

Personally, I dont believe it is anything more than an extreme Swamp Harrier - and I'm not even sure it is that unusual? What do the Museum gurus, in Wellington, Christchurch and Auckland, have in their collections? I've seen many birds that look much like this - though maybe none quite as dark in the head.

Eastern (and Western) Marsh Harrier has a different jizz to Swamp Harrier. I'm quite sure that Steve would have been struck by that.

Plus there is the little matter of Nelson being in the wrong hemishere, and about 8000 km from the Southern edge of the species winter range, which for a Northern hemishere breeder would be our summer!

And the habitat is wrong. Reedbeds for Marsh Harriers, not scrubby hillside.

I dont buy it. Lovely looking bird though.


Re: Mystery bird of prey?

Posted: Mon Sep 02, 2019 3:29 pm
by Colin Miskelly
Te Papa has about 30 male harrier study skins (both NZ and overseas). None is as strikingly patterned as Steve's bird

Ngā mihi