By Yoav Perlman
Swinhoe’s Snipe and Pin-tailed Snipe are a notoriously difficult species-pair. In fact they might be the only birds in the WP that even in perfect field conditions cannot be identified. In this post I will try to spotlight some potential ID features. Jari Laitasalo, an intrepid Finnish birder and ringer, has kindly allowed me to publish these images of a Swinhoe’s Snipe he took in May 2016 at Baikal Bird Ringing Station on the shores of Lake Baikal in eastern Russia. I will highlight here what little is known about their field identification (in fact I just need an excuse to show here Jari’s perfect images).
Both species breed right in the northeastern corner of the WP, in the northern Urals. In this context both are potential vagrants to the UK and western Europe. If I am not mistaken there are a few UK reports of ‘dark-underwing no trailing edge’ snipes – Martin once told me about one he had on Shetland some years ago but he couldn’t nail it. Swinhoe’s Snipe was recorded only once in the less extreme parts of the WP – a displaying male was in southeastern Finland in June – July 2008. It was identified by its unique display song, and during its display flights it did fan the tail and the characteristic outer tail feathers were seen well. Pin-tailed Snipe has been recorded twice in Italy (Sicily) – if I am not mistaken the only European records away from Urals. In the Middle East it is more frequent. In Israel it is a very rare but regular autumn visitor, just about annual in recent years, with 10 records up to late 2015. The situation in Israel is slightly awkward: three of these ten records involved ringed birds, and they were all Pin-tails (see some images below). All other seven records could not be separated positively from Swinhoe’s in the field. Until there is further evidence about how to identify them in the field, they are regarded by IRDC as Pin-tailed ‘by default’. Similarly, in eastern Arabia and Persian Gulf Pin-tailed is also a rare but regular visitor. If I am not mistaken there are also a couple of records of Pin-tailed Snipe in Sinai, Egypt. I must say that from the images I found online of Middle Eastern birds that were not trapped, the possibility that these were Swinhoe’s Snipe could not be eliminated.
Some clues towards identification
When you find a ‘dark underwing no trailing edge’ snipe in the WP, try to catch it! Please use a mistnet and not a gun as happened with the first Pin-tailed Snipe for Sicily that was shot by hunters (if I am not mistaken – couldn’t find anything on it online). In the hand first check the outer tail feathers. The outer tail feathers of Swinhoe’s Snipe are nice and broad, gradually broadening from the outermost pair inwards:
The outer tail feathers of Pin-tailed Snipe are very different – all outer tail feathers (normally 8 pairs but varies between 6 and 9 pairs) are of equal width, about 1.5 – 2 mm. This is a scan of a slide (over-saturated, sorry) I took of the 2nd Pin-tailed Snipe for Israel I took in November 1998:
And here’s another example, of a bird ringed at Tsora, Israel by Yosef Kiat:
But what to do with birds in the field? It may be possible that in exceptional images of a landing or preening bird, the shape of the outer feathers can be identified. However I have not had success with this yet. Andrea Corso told me that he found a difference in the tail shape in flight: Pin-tailed Snipe has a more diamond-shaped tail (similar to Raven), as a result of the short pin-feathers at the base of the tail. Swinhoe’s should have a more square- or gently rounded-shaped tail. I have tried to check this on images online but there are very few rear flight shots, and anyway in most it is impossible to say whether they were identified correctly. This is how Jari’s Swinhoe’s looks like in a view similar to flight – square tailed?
And Yosef’s pin-tailed in a similar view, when those pin-feathers are clustered: raven-shaped?
This is something that is certainly worth looking into, especially in birds of known identity. In general, I find Pin-tailed to be less-patterned above, with narrower fringes to scapulars and mantle braces compared to more boldly patterned Swinhoe’s. However this must be very variable, depending on wear and age.
Some more images of Jari’s Swinhoe’s:
Both species are rather silent, much less vocal than Common Snipe. Paul Leader and Geoff Carey discussed the possible differences in length in their excellent BB article, but they admitted that even to an experienced ear telling them apart is not straightforward. They suggested that Swinhoe’s is even more mute than Pin-tailed. Both species give soft take-off calls, though it is possible that calls of Pin-tailed are higher-pitched and clearer, while Swinhoe’s gives a lower-pitched, hoarser call. The bottom line is that it is worth sound-recording suspicious snipes, though it is not easy (I have tried several times but if the snipe did call it was very faint).
If you are lucky enough to be in an area where they breed and encounter a displaying bird, then display songs are sufficiently different. The song of Swinhoe’s is harsher and contains more ‘rrr’ notes, while Pin-tailed contains softer, more nasal notes. Check this educational post by Magnus Hellström.
Not much at the moment. Studying a large sample of birds in the hand in Hong Kong, Leader and Carey found no consistent differences between the two species other than outer tail feathers and perhaps vocalisations. They demonstrated that both species show considerable morphological variation in almost all features. Previous publications discussed features such as bill length, tail projection, overall patterns and pattern of scapulars, loral stripe and a few others. There might be something in the pattern on the scapulars: in Swinhoe’s, a higher proportion of individuals showed same-coloured outer and inner webs, while in Pin-tailed more individuals had white outer webs and buff inner webs. Check the images of the individuals above – in these individuals here this works but this is a tiny sample size and it is really about percentages of birds and does not apply to a single bird. And it would be very difficult to judge this on worn birds in the field, as WP vagrants would probably be.
This is a bird I photographed in November 2013 – hard to tell what it is. So frustrating.
Lior Kislev has kindly allowed me to use his flight shots of this same individual. Not easy to tell what the tail shape is. In some it looks more pointed and narrow, in others it looks more rounded and fuller.
Nice wing pattern:
And here it does look more pointed with a distinct ‘bulge’ at the base of the tail: pins?
Can I see pins here when its landing? BTW there is a Spotted Crake in this image too…
Some more information about Baikal Bird Ringing Station
This exciting ringing project started in 2012. If I am not mistaken they ring there only in Spring. Check their blog! They catch there mouthwatering Siberian species such as this stunner:
You can find more great images Jari took there this year on his Facebook page, and other images from previous years in his Tarsiger gallery. Many thanks to Jari, Lior and Yosef for allowing me to use their images.