راستی یه راهنمای کامل برای تشخیص شیکرای ایرانی
SOME NOTES ON IRANIAN SHIKRA IDENTIFICATION
Andrea Corso
Very scarce information are available on the identification of Iranian Shikra Accipiter badius in the Western Palearctic with nothing reported neither on the main raptors’ book for this area, the Forsman (1999), nor in the main birds identification guides such as Collins Bird Guide (Svensson et al. 2009) and Jonsson (1992). In other field guides and handbooks there are some limited information but in most cases, incredibly, the species is wrongly illustrated with plates showing misleading characters, as is the case in all the editions of the Birds of the Middle East (Porter et al.1992, 2001, 2010). This is partially because, for the former references, the species was an extreme vagrant (and still is, albeit less, a true rarity) into the limits of the Western Palearctic (but some border areas such as Kuwait) outside of the limited breeding grounds (N Iran, Armenia and Azerbaijan, the Caucasus) while for the latter, the one with wrongly depicted plumages, it is due to the illustration of other race than the ssp. cenchorides which occur into WP (hereafter Iranian Shikra) and which is paler, less marked and less contrasted than most of the other races, lacking indeed the dark wing-tip often shown in colour plates of many field guides. Illustration (mostly wrong at all or some points) and relevant text discussing its identification are reported for example by Beaman & Madge (1998), Ferguson-Lees & Christie (2001) and Gènsbol (2005) and most recently by Naoroji (2006) while very few articles on biding magazines dealing with its identification are available such as Clark & Parslow (1991), Labinger et al. (1991), Yosef et al. (2001), Yosef et al. (2002) but those mainly discussing in hand characters. In the field identification is reported though briefly by Dernjatin & Vattulainen (2004). Corso However, still a brief and easy to read yet lengthwise summary is lacking on birding magazines as well, and even more, on the web. After the recent claim of a putative Iranian Shikra at Batumi, which posed several identification problems also to highly skilled raptor watchers and birders, I think it could be of some interested to propose here a brief overview and summary of the main identification problems, based on museum studied of several tens skins (mostly the British Museum, Tring, Malmo and Wien Musem) and on field observation, mostly in Kazakhstan. Of course, the main likely species to distinguish is the similar Levant Sparrowhawk Accipiter brevipes.
- ADULT
1. WING-TIP: in most field guides, Iranian Shikra is shown showing a dark wing-tip as much as Levant or only slightly paler, with almost only Clark (1999) correctly reporting an adult female with pale wing-tip. Indeed most of the African taxa of A.badius have a quite dark and contrasting wing-tip, but the taxon occurring into WP, the ssp. cenchroides, has almost always a paler wing-tip, with only the more adult and marked males showing outermost primary dull or dark grayish-led. In these birds, the dark is limited to the very distal part of 2 to 3 (4) outer most primary (P10-P9, P10-P8 or P10-P7) wile on Levant adult male it is more solidly black or blackish and wider in both extension along the feather and in number of dark primaries. Also, in adult male Iranian Shikra usually there are several dark bars along the primary while in typical Levant the “hand” show a very contrasting dark fingered area with pale, almost unmarked base (lacking any dark barring or showing only an hint in most birds) and often even a dark trailing edge along the wing which is always missing in Iranian Shikra. In adult female Iranian Shikra, as contrary, the wing-tip is always pale with several dark bars all along the length (up to 9) while in adult female Levant the dark wing-tip is also rather dark, less than on male but yet visibly darker than on any adult female Iranian Shikra. NB: Some rare variant of (younger) adult female Levant could, mostly when abraded and sun-bleached, show a paler wing-tip with only fractionally dull outer “fingers”. In that case we should focus on the other field marks.
2. WING-FORMULA: all in all only the number of visibly “fingered” outer primary is an helpful character under field condition, but on photographs the complete wing-formula is a clinching character which deserve the highest attention being a key feature – Iranian Shikra has the 5th primary (P6) rather long and well projecting past the 6th (P5), this is as long as the 4th (P7) and almost as long as the 3rd (P8) so the wing-formula would be : wing-tip P8-P6 = , 5 fingered primary. In Levant instead, the P6 is shorter, often under good views visibly so, so the fingered primary are only 4 giving the Falcon-like jizz that we all know. The wing-formula will be: wing-tip P8-7= or P7 longest; P6 short, only slightly longer than P5 and shorter than P7. In hand, or very close up photos, the emargination in Iranian Shikra would be : very deep on inner web on P9-8-7, also rather deep on outer web of P6; in Levant inner web emargination only on P9-8, P7 not emarginated as well outer web of P6 not emarginated. The different wing-formula result in quite different jizz in the field (see under this).
3. PRIMARY-PROJECTION: On perched birds in the field, the primary projection on all the adults (as well as though less in juvenile), would be a rather good if not clinching character also of birds not facing the observer (where the iris colour and the underbody colour and pattern would be not visible) – in Iranian Shikra the PP is very short, broad and blunt, while on Levant is always much longer, narrower and more pointed. Also from above, the exposed primaries in Iranian Shikra are always paler while are black or blackish (male) or darker (female) in Levant.
4. UNDERWING: the underwing of adults female is in most Iranian Shikra less patterned, paler and showing only limited narrow rusty-orangish or tawny barring and/or spotting while is in most adult female Levant more densely and markedly patterned, with rather thick and wide barring on axillaries for example. On adult males the barring could be similar or same and is therefore of little relevance. Secondary of adult male are unbarred or almost so in Levant while show more defined and conspicuous barring in Iranian Shikra, while in female of the former there are usually 3 or 4 dark bars while there are up to 5 dark bars on female Iranian Shikra (same on juveniles), but there is a lot a variation on this and also it is hard to judge as highly depending on wing position/posture.
5. UNDERPARTS: in Iranian Shikra paler and less densely and broadly barred than in Levant, adult and chiefly 1st adult female Iranian Shikra have more extensively and visibly barred underparts than their adult male but the bars are wider and more defined and marked in adult female Levant; most importantly, the thigh-feathers of Iranian Shikra is unmarked or lightly barred by narrow bars while is densely and visibly barred in most Levant, on the latter very often also the lower vent and belly is barred and barring often extend to the undertail coverts, while those areas are clean white in Iranian Shikra.
6. UPPERPARTS: Usually of a colder and paler bluish-cerulean grey in Iranian Shikra, while are darker, warmer and more blue-led grey on Levant, with female more brownish or rusty tinged. Many 1st adult female Iranian Shikra could also be rather dark brown-tinged.
7. IRIS COLOUR: in Iranian Shikra range from deep yellow to yellowish-brown in adult female, in some of them (chiefly adult) could be also orange tinged or orange, while it is ranging from orange to red-orange bright in adult males. In Levant is always darker, less red or orange tinged, with only some younger adult female (occasionally only few males) showing paler iris that could appear, once reached by strong direct sun-light, orange tinged.
8. TAIL: according to Ferguson-Lees & Christie (2001) and many other sources Iranian Shikra would have a shorter tail than Levant; However, at least for the Iranian Shikra that is not true according to my museums measurements and direct personal field observation, with on average a longer tail – 179mm (20♀♀ ) e 155mm (8 ♂♂) against 166mm (30 ♀♀) e 153mm (13 ♂♂) of Accipiter brevipes. Therefore this result in a longer tail looking in the field, this even more emphasized by the shorter and rounder wing, with also, when perced, the visibly shorter primary projection (PP).
9. JIZZ: of really heavy relevance, being a clinching feature, is the jizz which with experience could be easily spotted on; due to the differences in the wing-formula, wing-length, tail length etc the two species appear different in the field in flight – Iranian Shikra appear to have a rounder and broader wing-tip, very similar to that of Sparrowhawk Accipiter nisus although on this the “hand” is larger, wider and less pointed. The “hand” is more pointed and narrower in Levant, and the lower wing profile, the trailing edge, is straighter, more parallel, while in Iranian Shikra the secondary are more bulging, appearing more convex with therefore a less parallel wing with a less straight lower profile. The tail appear longer, sometimes obviously so, in Iranian Shikra while is shorter in Levant, with length shorter often than the width of the wing-base. Indeed, the longer tail is also stressed by the shorter wing of Iranian Shikra, with Levant indeed having always a longer wing-chord and length (Vaurie, 1961) and by the wider “hand” appearance. The 5 fingered primary against the Falcon-like 4 of Levant is also often a rather obvious difference in the field. Differences in the bill structure and toe length and structure are helpful mostly in birds in the hands.
- JUVENILE:
Juvenile Levant show a paler wing-tip than adults, therefore this important field character is of no use. Juvenile male Levant usually show limited or no barring on the proximal part of the outer most primary, while these are obviously and markedly barred on juv. male; in Iranian Shikra, though the dark bars are narrower and less marked in male, there is an extensive number of bars in both sexes. The tail of juveniles is longer so the differences are slighter and less visible. However, differences on the length of P6 and on the wing-formula are already relevant and a key character, so that also the jizz is different also in juvenile. Regarding plumage, the main differences are:
1. UNDERWING: in most juvenile (but few palest male) Levant the underwing coverts are densely and obviously dark spotted/barred/blotched appearing in the field as dark and as patterned as the body, while in Iranian Shikra those are lightly marked, with narrower and lighter and sparser dark markings, appearing therefore paler (often wholly pale) than the body (more patterned though in juv. female).
2. UNDERPARTS: as for the underwing coverts, the body is below less densely patterned, with dark markings narrower, chiefly on belly and lower flanks, with thigh-feathers and undertail coverts only sparsely barred or almost unmarked white. In Levant, chiefly on female, the barring on thighs and undertail coverts is always more extensive, wider, darker and more visible in the field. NB: note that juv. female are often (always?) more densely patterned, with broader and more extensive dark markings. They are also darker above and with wider barring on tail and wings.
3. UPPERPARTS: usually paler and colder in Iranian Shikra, chiefly on juv. males, but of limited use.
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