SEPTEMBER 2009'S MYSTERY BIRD ANSWERS

Not as easy as they looked really these two, causing some real head-scratching along the way. Decisions were made however and you brave 23 gave them a whirl, so how did you go on?

Mystery Bird 17

There were six suggestions for what this brown blob could have been and one of absolutely no idea. Well, atleast they were honest! They ranged from birds as small as a Coal Tit to as large as a Rough-legged Buzzard but could any form of size be assessed from the provided image? Well, yes it could. Several entrants even managed to correctly identify the birds chosen perch as an Elderberry but either way I think it fair to say they leaves are very small compared to the bird itself and that alone is sufficient to reject our entries of Coal Tit (one vote) and Starling (2 votes). That left us with three species of raptor, Buzzard (1 vote), Rough-legged Buzzard (1 vote) and Marsh Harrier (17 votes!). Some confusion came of course from judging exactly what was what part of the bird but either way the plumage is too all-dark and uniform for either of the Buteos which left us with our correct answer, that 74% of you managed. A preening juvenile Marsh Harrier, the bright gingery-yellow patch being the crown as it nibbles away at the feathers on it's flank.

Juvenile Marsh Harrier, Cley, Norfolk, July 2009 (Ian McKerchar)

Mystery Bird 18

Well, it's a duck and that was the easy part over! To be fair this was in fact almost certainly the most difficult of all the mystery birds in the competition to identify and I'd like to point out at this stage that there was never an intention to mislead, only perhaps to educate ☺. That said, the photo is as came out of the camera. No trickery or jiggery pokery, but one that could be received by any rarity committee or that could be afforded 'death by internet forum' on several sites out there. Is it actually possible to pin it down to a single species though? Should we be making a decisive judgement on such a photo, one which could perhaps trip us up at any given moment?

Okay, firstly, answers. Teal (7), Pintail (4), Gadwall (1), Blue-winged Teal (6) and Garganey (5) were all submitted as correct answers (votes received for each in brackets). Reducing them quickly to only three potentials sees us quickly discard Pintail (incorrect head shape, bill shape, jizz and body feather patternation) and Gadwall (would display bright orange along the lower edge of the bill, lacks such neatly pale edged tertials and would still portray a conspicuous small white speculum). That only leaves us with the three 'teals', so where now? Well, (Common) Teal should have a fairly obvious little orange-yellow colour to the base of the bill, would not have such clearly edged white tertials and would show a conspicuous white patch along the base of the tail sides. This bird has none of those features but note that the apparent pale along the base of the tail sides actually runs the full length of the tail, unlike that found on (Common) Teal and in this instance is the outer tail feathers caught in the strong sunlight. No, Teal it is not I'm afraid. Strong sunlight I hear you say? As always, it's worth checking the lighting where possible and in this instance the subject is strongly lit from the left, head on as it were. Could this affect our judgement in assessing this photo? If you were on a rarity committee and received this image would it alter your evaluation? Does it have an impact on allowing us to separate the next two mystery bird suggestions of Blue-winged Teal and Garganey? Frankly yes and most of you had already guessed that. Clearly the sun is burning out any facial features the bird might portray in the image and we will have to reply on something else. But is there anything else to go on from this image? Erm, I don't know how to tell you this but the answer in my opinion is no! Blue-winged Teal has a more spatulate bill than Garganey (often with a finer tip with more pronounced curvature) and wouldn't normally (if you look in enough bird books that is!) have such clearly pale edge tertials but my field experience lends me to believe that both are very subjective, the bill shape is often angle relative (and often difficult to assess) and tertial edges can appear similarly pale edged. Some entrants mentioned the bird's speculum, both for and against both species but in fact I believe it is not a clear and decisive feature for either. The trailing edge to the secondaries on Garganey is usually broad and Blue-winged Teal very narrow indeed. On our mystery bird is appears narrow to my eyes, but narrow enough to be decisive? No. So, I think it's a fair result that the bird is not identifiable between Garganey and Blue-winged Teal off the provided photo but it is surprising that those entrants for Blue-winged Teal generally provided detailed reasoning for their choice but those for Garganey gave none. Why bother using it as a mystery bird then? Well, it's not to catch you out, honest. I suppose it's to prove just how difficult it can be assessing a bird's identification off a single image and the potential pitfalls that await those of us brave enough (or foolish enough ☺) to venture into offering identifications in such instances. Mystery bird competitions are one thing but t'internet identification forums are another!

So what was it? The answer looks clear to me and I found it difficult not to be more decisive but of course I already knew the answer. Had I not known what the species was nor where and when the image was taken then my opinion would clearly have been more cautious. As it is the bird was in fact a Garganey! Those five currently cheering though should ask themselves if they really could discount Blue-winged Teal in their appraisal but never the less, through luck or good judgement they got it right. Of course, the real odd decision here is that those six for Blue-winged Teal might well also cheer, for even though they eventually got it wrong, they still get a point for it as I find the photo inconclusive for separating the two. An odd decision I know but then again it was an odd round afterall! A dissatisfying result? No doubt it will be for some or perhaps many, but sometimes there's more to a mystery bird competition than just identifying the birds, if you know what I mean!

The Garganey guys were Tim Wilcox, Geoff Hargreaves, Mike Howard, John Frankland and John Tymon. Whilst the Blue-winged Teal chaps were Simon Warford, Dave Broome, Mark Rigby, John Rayner, Mike Chorley and Paul Brown.

A slightly better photo appears below. Note how the the acute change of angle in the bird's head gives rise to it's true pattern and the identification seems a whole lot easier now.

Garganey, Pennington Flash, August 2009 (Jon Taverner)

In an unusual round eight entrants managed to get both species correct (at either Garganey or Blue-winged Teal level) and they were Simon Warford, Dave Broome, Mark Rigby, John Rayner, Mike Chorley, Mike Howard, Paul Brown and John Tymon. Lessen thoroughly over though, no more of that kind of thing I promise! Gotta keep you on your toes though...

No change in the leader board as Paul Brown continues his reign and with North Ronaldsay seemingly devoid of megas (watch that change after I publish this!) he seems less likely to be detracted from his Manchester Mystery Bird title ambitions.