Monday 23 August 2010

AZORES STINTS


1) It has been suggested that this stint (centre bird) is a Little Stint. The photo was taken on 18th October 2005 at Cabo da Praia Quarry, Terceira, The Azores and I identified it as a first winter Semi-Palmated Sandpiper in the company of a White-rumped Sandpiper (left) and a Least Sandpiper (right). Several pro- Little Stint features have been suggested including the moulted mantle feathers (typically Semi-P does not moult until it reaches the wintering ground), the thin bill, neat buff fringes to the retained wing coverts, split supercilium, breast pattern (?) and the amount of primary projection (30-50% on Little Stint with 2-3 primary tips beyond the tertials with wing projection beyond tail: 20-30% on Semi-p). Patrick Lonergan also suggested that it could be an adult because of the pointed greater coverts.
Let's have a closer look :-)

2) The first question is 'what bloody age is it'? Well there are clearly two generations of upperpart feathers- the light grey scapulars and the brownish remiges (also the brownish rump and odd mantle feather). If it were an adult in winter plumage we would not see this kind of contrast (check out image 6 of a bird I identified, indeed, as an adult Little Stint the very same day). What about an adult with retained summer remiges and some moulted scaps.....could be (check out image 7) but I would not expect to see such uniform remiges- adult summer feathers in stints are generally a mix of different patterned feathers- also surely more wear ?? )
So- I think it's a first winter (for now) .

3) Stint sp. as above. Here it is again- with a Least Sandpiper (on right).

4) Turn round.




5) Now this is what I call a first winter Little Stint- taken in Cabo da Praia quarry on February 15th 2004. Look at those rusty fringes to the tertails, scaps and mantle and also the deep brown colour to the tertials. Also look at the large diffuse centres to the new moulted feathers (single dark shaft streaks to the bird in question). Interestingly there is very little primary projection on this bird and no sign of a split super (or any super for that matter) but on balance I would go for Little Stint .

'Grey' juvenile Little Stints do turn up from time to time in Europe but when I have come across them in the past they look grey and not 'brown'.


6) And this is what I call an adult winter Little Stint- taken on the same day and also seen alongside the stint in question. No contrast between mantle/scaps and remiges, diffuse centres to scaps, split super, thin billed- all point towards Europe.

7) Adult Semi-palmated Sandpiper at Cabo da Praia by KT Haataja, July 2010 (no permission obtained- don't sue me- no point I'm broke- spent all my money going to the Azores)

8) Semi-palmated Sandpipers on the Azores are rather variable. I attribute this to certain aspects of vagrancy- sourced from populations across a wide geographic range and also that anamolous plumages may be linked to vagrancy processes- an indication of trauma, mutation, etc. Image 8 shows a juvenile Semi-palmated Sandpiper, Cabo da Praia, 16th October 2007. This is a very dark semi-p. No sign of any anchor marks to the scapulars and also it has a very dark ground colour to the upperparts.

9) A fairly typical Semi-p (photo by Tobi Koppejan without permission- see note to plate 7) complete with anchor marks, cold tones, short primary projection but there is a hint of a split-super and also that bill could be stouter (no one is perfect).

10) Juvenile Semi-p taken in July 2009 on the Azores. Another brown 'bird' and I am not too impressed by those semi-palmations (can't actually see them). That super also looks split.

11) More Azores Semi-ps (October by Staffan Rodebrand)- remiges being a pretty good match for the bird in question.

12) This looks good for a Semi-p but look at that blinking primary projection- looks long. (19th October 2008). This was also quite a rufous individual.


13) Birds 12 and 13 were feeding together- we decided one was a long-winged and short billed Semi-P and the other was a long-billed and short winged (this bird) Semi-P. This bird has got the jizz of a Western (the primaries barely project beyond the tertails and the bill is long and curved) but I am not happy about that being a Western with those dull scaps and cap.

CONCLUSION: If you fancy getting very confused by stints than go the Cabo da Praia, Terceira, the Azores. Nowhere else in the world can you readily compare Nearctic and Palearctic counterparts side by side at extremely close range. Due to the vagrant context too it is quite possible that anomalous plumages/ moult and indeed a wide range of plumages (representing sources from a wide geographic range)- are linked/associated to (Azorean) vagrancy adding another layer of complexity to the matter.

The bird in question? It confused me for hours. In the end I flushed it to hear it call- the call was a very short and harsh micro-trill and I had the Little Stint flying round calling too (a single high pitched note). On balance (colour of remiges lacking rufous tones to the fringes, single dark shaft streaks to moulted winter feathers, bull necked appearance, rump colouration and the diagnostic call) I decided it was a thin billed, early moulted (early brood bird?) Semi-Palmated Sandpiper.

More pics of Semi-Palmated Sandpipers on the Azores here: http://www.birdingazores.com/index.php?page=commonbirddata&id=549#NotFirst

Comments very very welcome.