The Yellow Wagtail complex is notorious for its proliferation of subspecies and its great variety of age, sex and season-related plumages. The situation in Britain is relatively straightforward, with flavissima Yellow Wagtail the regular breeding taxon and nominate flava Blue-headed Wagtail a somewhat scarcer but nonetheless regular and relatively familiar migrant. Complicating matters, however, are scarcer, rare or potentially vagrant subspecies from the Continent. What’s more, intergrades between the recognised subspecies are frequent (they are the dominant type in some areas), while birds with anomalous plumage resembling a distant subspecies can occur seemingly anywhere. It is no wonder that the Yellow Wagtails have long been a minefield for both birders and taxonomists. There is, however, some order and structure within the group, with certain groupings discernible. These may allow identification, if not to subspecies level, then at least to the level of a subspecies pair or group. In Europe one such pairing is formed by the two southern subspecies: iberiae Spanish Wagtail and cinereocapilla
Ashy-headed Wagtail. These are sometimes aggregated with pygmaea (Egyptian Wagtail) into a proposed new species Motacilla cinereocapilla:
‘Southern Wagtail’ or ‘White-throated Wagtail’.
Spanish Wagtail
This subspecies breeds largely, as its name suggests, in Iberia, but it also nests in north-west Africa and southern France. Spanish Wagtail is not officially on the British list, but it is a likely vagrant and birds apparently of this form have been noted here. It will probably not be too long before one is accepted. Away from the breeding areas in a British vagrant context, males represent the best identification opportunity. These are mostly blue/grey-headed with white supercilia and therefore most resemble nominate flava Blue-headed Wagtail of west-central Europe and western Russia, but although somewhat variable, they generally differ in a number of features. Most notably, they show a clearly demarcated white throat, a rather narrow supercilium, particularly before the eye, and slightly darker forehead, crown, nape, lores and ear coverts. The last feature appears more ‘solid’, lacking a pale central patch, and the white lower eyering is weak. Blue-headed Wagtail, by contrast, is characteristically a mid-toned blue on the head with a broader supercilium, often some pale in the central ear coverts and a largely yellow throat. Female iberiae are debatably identifiable, but compared with Blueheaded may show a narrower supercilium and a clearly demarcated white throat. There are complications, however. Some male Blue-headed Wagtails can lack a fully yellow throat, while Spanish Wagtails intergrade regularly with Blue-headed in south-west and west-central France, and with Ashy-headed Wagtails along the French
Mediterranean coast (where such birds are in the majority). Intergrades naturally show intermediate characters, so Spanish x Blue-headed intergrades can show significant yellow in the throat, while Spanish x Ashy-headed intergrades tend to show a reduced supercilium. Other hybrid combinations, such as Blue-headed x thunbergi Grey-headed Wagtail (breeding in Fennoscandia and north-west Russia) and Blue-headed x feldegg Black-headed Wagtail (south-east Europe) might also resemble Spanish Wagtail. The most important feature is the call. Most Spanish Wagtails give a harsh, rather rasping tsrrreeep call with a strong rrr component, very different from the familiar soft call of flavissima ‘British’ Yellow Wagtail and Blueheaded and Grey-headed Wagtails. However, just to confuse matters, they can also sometimes give soft calls, too.
Ashy-headed Wagtail
This subspecies breeds in Sardinia, Italy, Sicily, Slovenia and north-west Croatia. It is already on the British list, with six accepted records to date, all of males in spring and most occurring in late April, coinciding with the main northward push of Yellow Wagtails from the western Mediterranean. As with its Iberian cousin, away f rom the breeding areas males offer the main opportunity. These are dark hooded with no supercilium (or just a trace over and behind the eye) and therefore most resemble Grey-headed Wagtail. However, unlike that subspecies (in which males show a yellow throat), the throat of Ashy-headed Wagtail is white and clearly demarcated. Females closely resemble female iberiae, but the supercilium may be even narrower or lacking altogether. Needless to say, there are caveats here, too. Firstsummer male Grey-headed Wagtail can lack a fully yellow throat, while Ashy-headed Wagtails intergrade with Blue-headed in eastern France, Austria, Switzerland and the Balkans, and as already described, intergrades with Spanish Wagtail are the dominant type along the French Mediterranean coast. Ashy-headed x Black-headed Wagtails have also been recorded. With all intergrades, intermediate characters are the norm. As with Spanish Wagtail, vocalisations are important, Ashy-headed Wagtail sharing the same harsh, rasping call.
Discussion
The easiest way to enjoy these fabulous wagtails is to visit their home ranges and see them in breeding habitat. However, both Spanish and Ashy-headed Wagtails are viable targets in Britain and males should certainly be searched for in spring. In this context it is worth bearing in mind the occurrence patterns of the two main confusion subspecies. Blueheaded Wagtails occur mainly in mid-spring
along with northbound flavissima Yellow Wagtails and are therefore likely to be present at the best time for a Spanish or Ashy-headed Wagtail. Grey-headed Wagtails, by contrast, occur later in May alongside other Scandinavia-bound migrants. Due to the complexities outlined above, formal acceptance of any of the rare subspecies might not be a formality. Claims of either should ideally comprise detailed notes, including notes on vocalisations (or, better still, sound recordings) and, preferably, also good photographs. However, if not attributable definitively to either subspecies (for example by virtue of intergrade characters), a harsh-calling bird might still prove acceptable as an ‘either/or’, that is a Spanish or Ashyheaded Wagtail. Indeed four such birds have already been accepted.
THREE: Male Spanish Wagtail (Teich, France, 7 April 2010). This Spanish Wagtail is superficially very similar to the preceding bird; indeed the length and breadth of the supercilum is little different. Note, however, that the ear coverts are a little darker and more ‘solid’, lacking the pale centre, while most importantly, the throat is both pure white with not even a hint of yellow and very sharply demarcated from the yellow underparts. In life this bird should give a harsh rasping call, unlike that of Blue-headed Wagtail, thereby confirming the identification.
TWO: Male Blue-headed Wagtail (Bremen, Germany, 4 May 2012). This bright male has a lovely clean blue-grey head and a prominent full supercilium, in this instance flaring a little more strongly behind the eye than the individual in photo one. Pale feathering within the ear coverts, giving a slightly ‘hollowed-out’ look, is typical of male Blue-headed Wagtail, as is the yellow throat. On this individual almost the entire throat is yellow except for a little white on the uppermost throat.
FOUR: Male Ashy-headed Wagtail (Tuscany, Italy, 30 March 2009). This bird lacks a strong supercilium and is therefore initially reminiscent of male Grey-headed Wagtail. Note, however, that most of the throat is bright white with only a little yellow on the lower throat. This makes it more likely to be an Ashy-headed Wagtail. The tiny, restricted pale mark behind the eye can be present on both Grey-headed and Ashy-headed Wagtails, so does not help with identification. If it was any stronger, however, it would be more suggestive of an intergrade. The yellow on the lower throat is perhaps a little extensive for a typical Ashy-headed Wagtail, so the identity of this bird would be best confirmed by considering the location (here Italy) and, most usefully, hearing a rasping call.
FIVE: Female Blue-headed Wagtail (Lesvos, Greece, 7 April 2006). Female Blue-headed Wagtails are essentially a muted version of the male, but are very difficult to separate from other Yellow Wagtail subspecies, including British Yellow and Spanish Wagtails. The appearance of this bird is typical, however, with soft blue-grey hues in the head, a prominent supercilium both before and behind the eye, pale-centred ear coverts and extensive pale yellow in the throat.
SIX: Female Spanish Wagtail (Tavira, Portugal, 5 April 2013). This female wagtail resembles the preceding bird, but its head is a little darker grey, the supercilium is very narrow, especially before the eye, and the throat is white. This combination of features belongs to Spanish Wagtail but, as always, the location – here, helpfully, Portugal – and the call would help to clinch it.
SEVEN: Female Ashy-headed Wagtail (Tuscany, Italy, 30 March 2009). This rather ‘hooded’ female would attract immediate attention in Britain. Its striking appearance, caused by the lack of a supercilium, resembles both Greyheaded and Ashy-headed Wagtails. The throat is largely white, perhaps suggesting Ashyheaded, although this can also be true of some, particularly first-year, Grey-headed Wagtails. We are therefore back to location (Italy again) and, crucially, the call. A harsh, rasping note would nail this bird as an Ashy-headed Wagtail.
EIGHT: Male Grey-headed Wagtail (Oulu, Finland, 21 May 2008). This grey-hooded male wagtail, completely lacking a supercilium, is striking indeed. The options can be narrowed down immediately to either Ashy-headed or Grey-headed Wagtails, and the extensively yellow throat establishes it as the latter. In life this bird would give a soft sweeep call identical to that of British Yellow and Blue-headed Wagtails. The Finnish location is of course also useful evidence.
NINE: Female Grey-headed Wagtail (Lesvos, Greece, 7 April 2006). This hooded wagtail is a little reminiscent of that in photo seven, although it has the same pale spot behind the eye as that in photo four. It is either an Ashyheaded or a Grey-headed Wagtail, and the white-looking throat might indicate the former. However, given that young Greyheaded Wagtails can also have white throats, we are not much further forward. Once again, we are back to location and call. The Greek location probably favours a migrant Greyheaded Wagtail, but to be totally confident we would need to hear it give a soft sweeep call.
ELEVEN: Blue-headed x Grey-headed Wagtail (Briebiza Marshes, Poland, 9 April 2015). This bird shows a perplexing mixture of features. Although most resembling a male Blueheaded Wagtail, its supercilium is noticeably narrow before the eye and the lores and ear coverts look quite solidly dark. This combination of characters is incompatible with any Yellow Wagtail subspecies, so this bird must be an intergrade. Things get very difficult from now on, as assigning intergrades is even more fraught than identifying ‘pure’ birds, but this bird’s Polish location suggests that a Blueheaded x Grey-headed Wagtail intergrade is most likely.
TEN: Female Black-headed Wagtail (Lesvos, Greece, 28 April 2007). Despite the pale feather fringes in the crown and nape, this bird appears very black headed. A few male Ashyheaded and Grey-headed Wagtails can appear darker than normal, looking black at range, but this bird is a female. The very black-looking lores and ear coverts on such a bird are therefore enough to identify it as a Blackheaded Wagtail. In life it would give a very harsh, rasping note which would at least eliminate Grey-headed Wagtail.
TWELVE: ‘Channel Wagtail’ flava x flavissima (Corsica, France, 18 April 2014). With its bluegrey head, prominent supercilium, palecentred ear coverts and largely yellow throat, this bird might be logged as a male Blueheaded Wagtail. However, the head is not the typical mid blue-grey of that subspecies, appearing instead a strikingly pale lavender grey. This is wrong for Blue-headed Wagtail, but is typical of male Blue-headed x British Yellow Wagtail intergrades, known colloquially as ‘Channel Wagtails’.
THIRTEEN: Male Black-headed x Blue-headed or Sykes’s Wagtail (Eilat, Israel, 16 March 2006). Again, this is a perplexing bird. The very dark grey head and narrow supercilium might suggest Spanish Wagtail, but the throat is wholly yellow. It resembles both Blue-headed Wagtail and Sykes’s Wagtail from Central Asia, but may be a little dark headed for either of these. If so, this might suggest an intergrade between a Black-headed Wagtail and either of these blue-headed subspecies. As ever, it may be better to leave some Yellow Wagtails unidentified.
FOURTEEN: Putative Spanish Wagtail (King George V Res, Greater London, 20 April 2010). This British-photographed bird shows a narrow supercilium before the eye, quite dark ‘solid’ ear coverts and an apparently white throat. These features are highly suggestive of Spanish Wagtail. Spanish Wagtail reaches us occasionally and is now on the British list. Good notes on the call (and preferably sound recordings) are necessary for one to be accepted. This bird remained frustratingly silent.
FIFTEEN: Putative Spanish Wagtail (King George V Res, Greater London, 20 April 2010). This is something of a ‘record shot’ of the same bird, but the combination of blue-grey head, narrow supercilium, ‘solid’ ear coverts and an apparently wholly white throat are still highly suggestive of Spanish Wagtail. As ever with ‘out of context’ potential vagrants such as this bird, the call is the key.