The oiled Juvenile harrier autumn 2011 - Shetland, UK (1 Viewer)

[Tib78]

Not sure whether or not this is the right place to post this. But here we go.

This oiled harrier: http://birdingfrontiers.com/2011/10/13/juvenile-pallid-harrier-identification/ has prompted an interesting discussion on Birding frontiers, with the great input of JanJ.
Further discussion on this bird here: http://birdingfrontiers.com/2011/10/19/identification-update-pallid-harrier/

First of all: Has this bird been accepted/rejected by the British RC (and why)? or is the record acceptance still pending?

One thing that surprises me is that seemingly no one has suggested the possibility of a (pure) juvenile Montagu's. The debate on the wing formula minutiae is certainly interesting and enlightening but if we step back for a second and look at the whole bird...well, I feel montagu's should be considered a very serious option in this case.

***Edit: Actually I see Montagu's has been suggested more than once in the comments. Especially by Lars Svensson himself. That makes me feel a little bit better, at least i won't look like a total idiot if the bird is identified as something else!***

To my eyes the structure/jizz of this bird looks perfect for Montagu's. For example, if the only picture available were photo h : http://birdingfrontiers.com/2011/10/13/juvenile-pallid-harrier-identification/img_5951a/ I would have said juv Montagu's straight away (which is a bit worrying...) because of the long tail, massive wings (long hand) and very slim body. But of course juv Pallid and Montagu's are quite close in terms of structure, and relying on jizz from still pictures is not advisable.

The problem with the oiling is that it does not a allow a precise and confident assessment of the plumage characteristics. The head pattern especially seems to vary from an image to another, yet at no point it seems to favour Pallid to my eyes: the collar looks thin and very rufous (concolorous with the underparts) and does not stand out very well. Some images show a lot of white around the eye, but again it seems to vary. The colour of the underparts is rather intense too, but I guess it could be imputable to the fulmar oil.

Now if we come back to the wing formula and especially the emargination of P9. It is established that the emargination of P9 is hidden by the primary coverts on Pallid (and Hen) while it is situated further up the feather on Montagu's and is therefore visible.
On the Shetland bird, the emargination of P9 seems concealed, however owing to the combination of: 1)foreshortening angle (the wing is not held at a 90° angle), 2)state of the feathers and 3) lack of crystal clear definition I am not sure the emargination would be visible. I attached a picture of a young female Montagu's by Stephen Daly. On this image, the P9 emargination is far from obvious to me, it may be because of the inner web of P10 overlapping with the outer web of P9. I originally found the picture on the surfbirds gallery: http://www.surfbirds.com/gallery/search2.php?species=Montagu's Harrier

Continuing with the wing formula, like Jan I am seeing a notch on the inner web of P7. But I would interpret it differently: the notch looks shallow to me, which is perfect for Montagu's.

The underwing pattern is largely accepted as one the crucial feature to look at when identifying juv pygmac harriers. Again I am going against the finder's opinion here, but the primary pattern looks better fon Monty's to me: the trailing of the inner hand looks as dark as the primary barring and the fingers are largely dark.
As far as I know, the primary barring could fit either species.

So I would be pleased to read more comments on this bird (comments from the BBRC would be especially welcome, if any).

 

[wolfbirder]

Looks like a dark-morph juv Monty to me.

 

[Tib78]

Looks like a dark-morph juv Monty to me.

At least we agree on the species.
But dark morph Monty's are wholly blackish (except for some whitish area on the underside of the primaries) see the 2cy female attached that I photographed on my local patch this spring (stunning bird and a nice surprise!)

As far as I know, the primary barring could fit either species.

In fact, looking again at the pictures, I'd say the primary barring is perhaps better for monty's. The bars are thicker on the inner hand and get thinner on the outer hand (ok for both species). But they are regularly disposed and rather evenly spaced, a pattern more in line with Montagu's. Pallid usually shows a more anarchically patterned hand and the bars are often concentrated towards the basal section of the feathers.

More input needed, please guys, it's a difficult bird!

 

[lou salomon]

hi tibault,

having looked at the pics some time i still feel it difficult with so many contradictory features or impressions. i think the oiled state of the bird might change the impression of some of the structural features by laying the feathers more tight to the body. first impression (first pic) was quite positive for pallid: i see a clear and long collar and a boa in ian cowgill's pic, the dark cheek 'moon' also reaches far down - wings look broad enough for pallid. wing formula a bit hard to asses in this position, a foreshoretened view and disturbed by the gap between p5 and p6.
p10 looks long for pallid though, better for monty, but i've seen many pics where the impression of p10 length is changing in different views...
photo a indeed shows a very lanky bird with a long hand but i fear the long-tailed and slim-bodied impression might be caused by more tight lying feathers? on the other hand this effect could also cause the impression of a very long tarsus (good for pallid).
pale eye crescents are more in line with monty's but i think are within pallid variation, and i think they look larger in pics a, b and c because pale parts are eating into dark in such blurry pics.
my immediate impression of the inner primary tips was like yours: too solidly dark for pallid. but then i saw the other pics and, admittedly grey (or 'broken by pale') dark tips are ok for pallid.
i don't see the wingtip strongly dipped in black like you (pics 1 and a) and i don't see the underwing barring as regular as you, esp. in pic a it looks quite irregular but have to admit this feature works for me only in extreme cases as it is confusingly variable in pattern and strength (in both sp.).
can't tell much about notches and emarginations from these pics but i don't see a hen harrier influence in this bird at all (if talking about a hybrid).
in the field, looking through bins, it's often easier to asses structure in a moving bird, but well, we have pics.
all in all, even thought the structure strongly suggests monty's (like in pic a), i'm worried about face pattern with the long dark cheek mark that might be shrunk in broadness in pics a,b,c by exagerrated lower eye crescent, lankyness being possibly caused by oil and uncertainty of underwing pattern makes me stay on a pending position....:-C

cheers

 

[Valéry Schollaert]

I understand why people think of a Pallid, thus I understand Tib's analysis that Monty matches better. Reading different comments on the bird by real specialists, I think it will be difficult to find an agreement...

If I had to vote, I'd probably still vote Pallid, but my opinion on this bird is not worth a lot unfortunately.

Even more unfortunate is the condition of that poor things... another story of course.

 

[dantheman]

At least I've got Oiled Harrier on my UK list then ...

As part of an influx of Pallid Harriers at the time, how rare would a Montagu's have been on Shetland (generally, and at that time of year)?

Can't really comment on the id from personal experience - it had already been id'ed as Pallid, and looked ok for one, allowing for the fact that features like boa etc were there, but partially obscured. Plus there were other birds to look for ...

 

[gerdwichers8]

To me, this bird mostly looks like a Montague's juvenile.
I see to the plumage in a whole nothing that makes me favour a Pallid over a Monty's and if I watch the most persistent plumage feature, the pattern to the inner hand towards the base of the outer primaries, I don't think it looks good for Pallid at all.
Given the wingformula, I fail to see any hybrid features that show any mix with Hen. ( and possibly a cause for disturbance in the plumage pattern?) No notch at p5.
Looking upon the comparison in between the length of p3 p4 I might go either way, but looking upon the comparison in between p1-2 and p5-6 I will go with Montague's

 

[smiths]

I lean towards Montague's Harrier too.

 

[JANJ]

I,m also inclined to identify the oiled harrier as Montagu's. The main reson for the doubt I expressed was the wingformula and the notched p7. Sructurally it looks better fot Montagu's, notice the pin thin tail in some of the pic. I'm not aware of it's further destiny.

JanJ

 

[tconzemi]

Despite the help of my little friend Pinot noir I cannot evaluate the notch on P10 and emarginations on P9 and P7 with any certainty. Well at least I do not see Hen harrier features. Wing formula seems equally difficult, but I fully agree that the tips of inner primaries are very well marked. Even if left unidentified there are very few features pointing towards Pallid.