Eastern yellow wagtails in Europe: identification and vocalisations

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295
[Dutch Birding 36: 295-311, 2014]
The yellow wagtail Motacilla complex keeps
birders busy. Not only can the different taxa in
the complex be challenging to identify, there is
also ongoing debate about relationships between
different taxa. The complex is widely distributed
in the Palearctic region (and into the Nearctic re-
gion in Alaska, USA) and is highly polytypic.
Nowadays, usually 13-16 taxa are recognised,
mainly based on the head pattern of males in
summer plumage (Alström et al 2003). When fol-
lowing the biological species concept (BSC), the
complex is usually described as a single species,
‘Yellow Wagtail’ Mava, or more recently as two
species, ‘Western Yellow Wagtail’ M ava and
Eastern Yellow Wagtail M tschutschensis (table 1;
Alström et al 2003, Gill & Donsker 2014). When
following the phylogenetic species concept (PSC)
most forms are given species status, a view adopt-
ed by, for instance, the Dutch committee for avian
systematics (CSNA), which decides on taxonomy,
nomenclature and status of Dutch (sub)species
(Sangster et al 1999). Until now, CSNA appears to
recognize 10 species (cf the Dutch Birding list of
bird names; www.dutchbirding.nl): ‘British’ Yellow
Wagtail M avissima, Yellow-headed Wagtail
M lutea, White-headed Wagtail M leucocephala,
Blue-headed Wagtail M ava (including Sykes’s
Blue-headed Wagtail M f beema), Grey-headed
Wagtail M thunbergi, White-throated Wagtail
M cinereocapilla (including Ashy-headed Wagtail
M c cinereocapilla, Spanish Wagtail M c iberiae
and Egyptian Wagtail M c pygmaea), Black-
headed Wagtail M feldegg, Eastern Yellow Wagtail
M tschutschensis (including Siberian Wagtail M t
Eastern yellow wagtails in Europe:
identication and vocalisations
 SanderBot,DickGroenendijk&HHermanvanOosten
395 Yellow wagtail / gele kwikstaart Motacilla, rst-year, Hangzhou, Zhejiang, China, 12 September 2009 (Jonathan
Martinez). Based on location, probably eastern yellow wagtail. Not all eastern yellow wagtails have grey-and-white
plumage; note yellow undertail-coverts. Without calling, this individual would go unnoticed in Europe.

296
EasternyellowwagtailsinEurope:identicationandvocalisations
plexa; cf Banks et al 2004, contra Alström et al
2003), Green-headed Wagtail M taivana and
Manchurian Wagtail Mmacronyx. For this paper,
we give Siberian Wagtail species status, M plexa,
and we use Alaskan Wagtail as the name for
(nominate) M tschutschensis (table 1). Hereafter,
we indicate all yellow wagtail taxa by their scien-
tic name.
From a European birder’s view, not only local
yellow wagtail species are of interest but also spe-
cies from as far away as East Asia, as some may
turn up as vagrants. Not many birders are familiar
with the East Asian taxa, because they are not de-
picted in important European eld guides (eg,
Svensson et al 2009), although they appeared in
some recent ones (Howell et al 2014, Vinicombe
et al 2014). Recently, there have been claims in
western Europe of East Asian yellow wagtails,
mostly of rst-winter birds in late autumn. They
are identied by their cold grey-and-white plum-
age which is more brown-and-yellow in western
taxa, and their rasping ight call which is very dif-
ferent from the ight call of north-western
European taxa. Of three rst-winter birds in
Europe, an eastern origin has been proven by mo-
lecular analysis: one collected on Fair Isle, Shet-
TABLE 1 English and Dutch names and taxonomy of yellow wagtail Motacilla complex followed in this paper, in
IOC (Gill & Donsker 2014) and in Clements et al (2013), respectively.
English name Dutch name this paper Gill & Donsker 2014 Clements et al 2013
’British’ Yellow Wagtail Engelse Kwikstaart Mavissima Mfavissima Mfavissima
Yellow-headed Wagtail Kaspische Kwikstaart M lutea M f lutea M f lutea
White-headed Wagtail Witkopkwikstaart M leucocephala M f leucocephala M f leucocephala
Blue-headed Wagtail Gele Kwikstaart Mavaava Mavaava Mavaava
Sykes’s Blue-headed Wagtail Russische Gele Kwikstaart Mfbeema Mfbeema Mfbeema
Grey-headed Wagtail Noordse Kwikstaart M thunbergi M f thunbergi M f thunbergi
White-throated Wagtail Witkeelkwikstaart M cinereocapilla
Ashy-headed Wagtail Italiaanse Kwikstaart M c cinereocapilla M f cinereocapilla M f cinereocapilla
Spanish Wagtail Iberische Kwikstaart M c iberiae M f iberiae M f iberiae
Egyptian Wagtail Egyptische Kwikstaart Mcpygmaea Mfpygmaea Mfpygmaea
Black-headed Wagtail Balkankwikstaart M feldegg M f feldegg M f feldegg
Siberian Wagtail Siberische Kwikstaart M plexa included in thunbergi M tschutschensis plexa
Alaskan Wagtail Alaskakwikstaart M tschutschensis M tschutschensis tschutschensis M t tschutschensis
Manchurian Wagtail Mantsjoerijse Kwikstaart Mmacronyx Mtmacronyx Mtmacronyx
Green-headed Wagtail Groenkopkwikstaart Mtaivana Mttaivana Mttaivana
M t angarensis
396 Citrine Wagtail / Citroenkwikstaart Motacilla citreo-
la, rst-year, Choroki delta, Batumi, Georgia, 25 August
2012 (Albert de Jong). Note that pale supercilium does
not surround rear of ear-coverts in this individual.
397 Yellow wagtail / gele kwikstaart Motacilla, rst-year,
Palau Mantanani, Sabah, Malaysia, 11 October 2012
(DaveBakewell). Lack of supercilium suggests Siberian
Wagtail M plexa or Manchurian Wagtail M macronyx.
This is a very dark individual; most plexa and macronyx
show white supercilium but not as marked as in Green-
headed Wagtail M taivana.

297
land, Scotland, on 9 October 1909; one in Devon,
England, in December 2010; and one on Tory
Island, Donegal, Ireland, in October 2013.
Genetically, all belong to either tschutschensis or
plexa (Haig 2010, Collinson et al 2013; http://
birdingfrontiers.com; plate 404-406). These
records constitute the rst for Siberian Wagtail or
Alaskan Wagtail (ie, north-eastern yellow wagtail)
in Europe and illustrate the vagrancy potential.
In this paper, we summarise current knowledge
of identication of rst-winter eastern yellow
wagtails by plumage. We also present criteria to
differentiate their ight calls from other yellow
wagtails and Citrine Wagtail M citreola. The name
eastern yellow wagtail can be confusing since in
the BSC Eastern Yellow Wagtail is the name for all
the eastern subspecies combined, while in the
PSC this name is often used for M tschutschensis.
In this publication we use the name eastern yel-
low wagtail only in lower case and only for any
combination of plexa, tschutschensis, taivana and
macronyx.
The ‘plexa’ problem
Studies show that there are three genetic clades in
the yellow wagtail complex. First, mitochondrial
and nuclear DNA sequences suggest a deep split
between plexa, tschutschensis, taivana andmacro
nyx on one hand and all other taxa on the other
(Ödeen & Alström 2001, Alström & Ödeen 2002,
Voelker 2002, Pavlova et al 2003). This results in a
western and eastern clade. The western species
are genetically usually indistinguishable from
each other (Alström et al 2003, Collinson et al
2013). However, the eastern clade can be further
divided in a north-eastern clade (with plexa and
tschutschensis) and a south-eastern clade (with
taivana and macronyx; Pavlova et al 2003).
Based on morphology, Alström et al (2003) syn-
onymised plexa, which breeds east from at least
83-85°E, with thunbergi, as both taxa only show
slight plumage differences (cf Collinson et al 2013).
Genetically, however, plexa is different as it is part
of the north-eastern clade, whereas thunbergi is
part of the western clade (cf Pavlova et al 2003).
To complicate things further, Pavlova et al
(2003) present genetic evidence that plexa occurs
much further west (c 69°E; black star in gure 1)
than previously known. So, either plexa is genu-
inely an eastern yellow wagtail taxon which is
contiguous in range with the morphologically
similar thunbergi, or it represents a population of
thunbergi that has picked up north-eastern clade
DNA owing to historical or ongoing introgression
with tschutschensis (Collinson et al 2013). Since
both ight call (see below) and genetics of plexa
differ from thunbergi (while it differs morphologi-
cally from tschutschensis), we exclude plexa from
thunbergi and treat it as a taxon on its own.
Clearly, more research on plexa is needed to de-
termine its range and relationships.
EasternyellowwagtailsinEurope:identicationandvocalisations
FIGURE 1 Putative breeding distribution of yellow wagtail Motacilla complex in Palearctic, largely redrawn from
Alström et al (2003). Vertical black line represents 84°E, presumed border of Grey-headed Wagtail M thunbergi and
Siberian Wagtail M plexa according to most literature. Black star represents Yamal, where Pavlova et al (2003) found
plexa on basis of DNA, close to border of Western Palearctic.

298
Ageing of wagtails in autumn
Most rst-winter yellow wagtails are readily iden-
tied from adults by retained juvenile tertials and
greater and median coverts. These show whiter,
clear-cut pale edges and tip than adult-type feath-
ers (Svensson 1992, Jenni & Winkler 1994, Alström
et al 2003). During autumn migration, rst-winters
have moulted a variable (but usually small)
number of these juvenile-type feathers. The pres-
ence of retained juvenile tertials or greater and
median coverts (contrasting with the freshly
moulted adult-type feathers) indicates a rst-win-
ter (Svensson 1992, Jenni & Winkler 1994, van
Duivendijk 2011; plate 398). As autumn migra-
tion proceeds, the extent of post-juvenile moult
decreases, and birds seen in southern Scandinavia
in late autumn usually have retained all juvenile
median and greater coverts (Jenni & Winkler 1994,
Alström et al 2003).
Identication – morphology
Allplumages
In both eastern yellow wagtail and Citrine Wagtail
the hind claw is on average longer than in western
taxa but there is considerable overlap (table 2).
Thus, when a yellow wagtail in Europe shows a
long hind claw (plate 403) this is an indication,
but not proof, of eastern origin.
First-winter Citrine Wagtail
How to identify rst-winter Citrine Wagtail is dealt
with extensively in, eg, Grace & Lancaster (1990),
Alström et al (2003), van Duivendijk (2011) and
Howell et al (2014) and here we only highlight
characters relevant for separating rst-winter
Citrine from eastern yellow wagtails. Separating
Citrine from western yellow wagtail taxa is mostly
easy, because the majority of rst-winters of west-
ern yellow show a variable amount of yellow on
the undertail-coverts. Because the percentage of
grey-and-white birds is much higher in eastern
species, confusion with Citrine is more likely. This
is especially the case when juvenile median and
greater coverts are retained, creating a clear-cut
whitish wing-bar, similar to that of Citrine. In these
cases important characters pointing to Citrine are:
1 dark base of the lower mandible (usually pale in
yellow wagtail); 2 even broader white wing-bars;
and 3 head pattern with completely whitish-
framed ear-coverts, brownish forehead, pale lore
and ‘hollow-centred’ ear-coverts. However, not
every Citrine shows completely whitish-framed
ear-coverts (see plate 396 where the pale super-
cilium does not surround the rear of the ear-
coverts). Citrine and yellow wagtails occasionally
hybridize (Shirihai 1990, Lehto & Lehto 1997,
Alström et al 2003, Draaijer & Slaterus 2012,
Shurulinkov & Osvoboditel 2012) and their off-
spring show intermediate characters. Unfortunately,
rst-winter birds of proven hybrid origin remain
undescribed.
First-winter birds
For a long time, birders in western Europe are
aware that rst-winter yellow wagtails can have a
grey-and-white plumage, instead of the usual
more brown-and-yellow plumage. These individu-
als were mainly used to illustrate that separating
rst-winter Citrine Wagtail from yellow wagtail is
not always straightforward (Grace & Lancaster
1990, Aymí 1995). However, when nding a grey-
and-white rst-winter yellow wagtail, one should
not only exclude Citrine but also consider eastern
yellow wagtail. Grey-and-white birds are rare in
the European species (except in feldegg) but are
EasternyellowwagtailsinEurope:identicationandvocalisations
398 Yellow wagtail / gele kwikstaart Motacilla, rst-year,
Ebro delta, Tarragona, Spain, 11 September 2012 (Raül
Calderón). Note moult contrast in greater coverts with
inner one moulted adult-type, remaining outers un-
moulted juvenile-type.
TABLE 2 Length (mm) of hind claw of yellow wagtails
Motacilla and Citrine Wagtail M citreola (Alström et al
2003)
Taxon Average Range Sample size
Mavaava 9.4 7.1-14.9 58
Mavabeema 9.6 7.9-12.9 33
M feldegg 9.5 7.6-11.3 23
M tschutschensis 11.1 9.9-13,8 19
Mtaivana 11.0 9.6-13.6 19
Mmacronyx 11.6 9.6-14.6 13
M citreola citreola 10.7 8.2-13.6 37

299
common in, eg, beema, tschutschensis and taiva-
na (Alström et al 2003). Aymí (1995) trapped more
than 5000 yellow wagtails (avissima, ava, thun-
bergi and cinereocapilla) at Ebro delta, Spain, and
concluded that c 1% of the trapped birds showed
a grey-and-white plumage. Persson scored only
0.1% of his trapped 20 000-40 000 individuals as
grey-and-white but this frequency increased in
late autumn (Persson, in Aymí 1995).
Helpfully, the grey-and-white plumages of west-
ern and eastern birds may differ subtly. Even
though scored as grey-and-white, birds trapped by
Aymí (1995) show brown-grey instead of grey up-
perparts, with pure grey usually restricted to rump
and uppertail-coverts. This creates a marked con-
trast between the grey rump and the remaining
brown upperparts (Aymí 1995; plate 402). Many
grey-and-white birds in eastern yellow wagtails
do not show brownish upperparts, and appear
monochrome. Unfortunately, such monochrome
birds do occasionally also occur in ava which
makes them probably indistinguishable to simi-
larly coloured eastern yellow wagtails (Alström et
al 2003). Grey-and-white birds are often females
(Aymí 1995, Alström et al 2003).
Grey-and white birds become increasingly
common further east. In beema, a quarter to one-
third of the rst-winter birds are grey-and-white.
In feldegg and tschutschensis, one-third to almost
half of all rst-winter are grey-and-white and this
is true for c 50% of all taivana. Information is lack-
ing for lutea, leucocephala and macronyx (Alström
et al 2003). Learning whether there are differences
among grey-and-white birds of the different taxa
is not an easy task: rst-winter yellow wagtails are
variable and show an even larger overlap in plum-
age characters between the taxa than in adult
plumage. Moreover, rst-winter birds are often
seen on migration outside their breeding areas,
which excludes distribution as an identication
clue. To overcome this problem, Alström et al
(2003) studied differences among eastern taxa
using the limited sample available of birds col-
lected in early autumn on their respective breed-
ing grounds.
In general, head patterns of rst-winter birds
match adult birds but with more overlap. Taivana
appeared to be the species with the strongest head
markings in rst-winter plumage, showing a
prominent supercilium, dark lore, whitish broken
eye-ring below the eye and rather uniform ear-
coverts (cf plate 400), probably never matched by
399 Yellow wagtail / gele kwikstaart Motacilla, rst-year, Cheongju, Chungcheongbuk-do, South Korea,
19 September 2005 (Soon-Kyoo Choi)
EasternyellowwagtailsinEurope:identicationandvocalisations

300
400 Yellow wagtail / gele kwikstaart Motacilla, rst-year, Dangjin, Chungcheongbuk-do, South Korea, 4 February
2007 (Soon-Kyoo Choi). Note prominent supercilium and uniform ear-coverts, suggesting Green-headed Wagtail
M taivana. 401 Yellow wagtail / gele kwikstaart Motacilla, rst-year, Lista, Vest-Agder, Norway, 20 October 2003
(Martin Eggen). C 10 grey-and-white, raspingly calling yellow wagtails were noted in southern Norway in late
autumn 2003.
EasternyellowwagtailsinEurope:identicationandvocalisations

301
402 Yellow wagtail / gele kwikstaart Motacilla, rst-year, Ebro delta, Tarragona, Spain, 11 September 2012
(RaülAymí). Note brownish hue on back, contrasting with grey rump.
403 Yellow wagtail / gele kwikstaart Motacilla, rst-year, Out Skerries, Shetland, Scotland, 10 October 2011
(Michael McKee). Note very long hind claw, indicative of eastern yellow wagtail.
EasternyellowwagtailsinEurope:identicationandvocalisations

302
404 North-eastern yellow wagtail / Siberische Kwikstaart/Alaskakwikstaart Motacilla plexa/tschutschensis, rst-year
female (JMartinCollinson/NationalMuseum Scotland). Collected on Fair Isle, Shetland, Scotland, on 9 October
1909. Note long hind claw and white throat and undertail-coverts, underparts with yellow wash. Either plexa or
tschutschensis based on DNA. 405 North-eastern yellow wagtail / Siberische Kwikstaart/Alaskakwikstaart Motacilla
plexa/tschutschensis, rst-year, Colyton, Devon, England, 14 December 2010 (SteveWaite). Either plexa or tschu-
tschensis based on DNA. Note yellow fringe on moulted longest tertial.
EasternyellowwagtailsinEurope:identicationandvocalisations
thunbergi and macronyx. Compared with tschu-
tschensis, taivana shows on average darker and
more uniform ear-coverts but there is much over-
lap (Alström et al 2003). Taivana has a broad su-
percilium, which reaches the bill, is often notice-
able square-ended and is broad along its entire
length, whereas tschutschensis often has a ne su-
percilium, not reaching the base of the bill and
ending behind the eye in a point (Alström et al
2003). First-winter tschutschensis is similar to
thunbergi but often shows more uniformly col-
oured ear-coverts (Alström et al 2003). Not much
is known about rst-winter plumages of plexa and
macronyx but since adult plumages have only a

303
narrow supercilium or lack one altogether, this is
probably also reected in rst-winter plumage
(cf plate 397). Thus, rst-winter birds in East Asia
with only a weak supercilium more likely concern
plexa or macronyx, rather than tschutschensis
or taivana. We conclude that rst-winter eastern
yellow wagtails are very variable and thus cannot
usually be assigned to species level on morphol-
ogy alone.
Identication – ight calls
Materialandmethods
Recordings used in this paper were made by the
authors, taken from the online avian sound-col-
lection website www.xeno-canto.org or kindly
provided by others. We ascertained using ight
calls from birds: 1 recorded on alleged breeding
sites; and/or 2 recorded in spring (summer plum-
age males) and visually ascertained to taxon-level;
and/or 3 birds outside their breeding sites but with
distinctive appearance. The number of recordings
used in this paper for each species is given in table
3. Sonagrams were created in Raven software
(Cornell Lab of Ornithology, 2003-09). To en-
hance comparability between sonagrams we used
the same ‘sonagram sharpness’ throughout (value
of 189). To enhance sonagram clearness and re-
veal details we increased the volume and adjusted
‘brightness’ (value 71 in all but beema for which
we used 90) and ‘contrast’ (value of 60). Vertical
axes are spaced 0-10 kHz in all sonagrams and
horizontal axes as long as needed, depending on
the length of each recording. Note that in all g-
ures with ight calls (gure 4-9) the space be-
tween the sonagrams is shortened and that a hori-
zontal line at 7 kHz is added to facilitate com-
parison of the ight calls of the different taxa in
each gure.
Songversusightcall
Vocalisations are important in identifying yellow
wagtails. In fact, many putative eastern yellow
wagtails are, apart from their general grey-and-
white plumage, rst noted by the harsh quality of
their ight calls, recalling Citrine Wagtail. However,
since the rasping ight call is not unlike the song,
we rst describe the song of yellow wagtails. The
most common song type in yellow wagtails is
probably one of the most modest in song birds. In
general, it consists of two repeated rasping notes
although sometimes one or three song strophes are
given. Birds mostly sing their calmly repeated se-
quence of 4-5 sec (Alström et al 2003, Svensson et
al 2009) from the top of a song post like a bush or
a fence wire. Occasionally, these song notes are
given in ight. In addition, a rather weak and com-
plex, prolonged twittering song is given in which
ight call elements (see below) are mixed. An ex-
ample of this song type is presented in gure 2.
Importantly, the most frequent song notes in yel-
low wagtails sound rather harsh and because song
notes can be given without repetition and in ight,
these sounds are easily and perhaps frequently
mistaken for ight calls (cf Groenendijk & van
Saane 2008). Supercially, a rasping ight call
looks like a single harsh song strophe, an example
of which is presented in gure 3b. However, the
separate song strophes are longer in duration, the
saw-structure of the descending part in a song
strophe is in general much less pronounced and
the rst rising part of a song strophe is less com-
plex. In addition, note that in most cases the sepa-
rate song strophes are most often repeated twice
(Groenendijk & van Saane 2008).
Flight call – all yellow wagtail taxa
Flight calls in yellow wagtails sound monosyl-
labic. In fact, however, typical ight calls of yel-
low wagtails consist of two parts which are easily
visible in a sonagram (gure 3a). The duration of a
ight call is c 0.2 sec. The rst part is a rising ele-
ment, very short in duration and in a sonagram
visible often as a double line rising from c 2 kHz
to c 8.5 kHz. The second part of the ight call
starts at c 8 kHz and is dropping down to c 3.5
kHz. So, note that the start of the rst part (nor-
mally c 2 kHz) and the end of the descending sec-
ond part (normally c 3.5 kHz) differ in frequency.
Furthermore, the second part is longer in dura-
tion. So the ight call of all yellow wagtail taxa
resembles an inverted ‘v’ with a rising leg longer
in frequency range and a descending leg shorter
in frequency range. Note that the rasping quality
of the ight call of southern and eastern species of
TABLE 3 Sample size of different wagtail Motacilla taxa
used in ight call analysis
Taxon Sample size
Mavissima 10
Mavaava >30
Mavabeema 18
M thunbergi 10
M cinereocapilla cinereocapilla 7
M cinereocapilla iberiae 12
M feldegg 10
M plexa 3
M tschutschensis 2
Mtaivana 2
Mmacronyx 3
M citreola 10
EasternyellowwagtailsinEurope:identicationandvocalisations

304
FIGURE 4 Flight calls of taxa be-
longing to north-western group:
1-2 Blue-headed Wagtail / Gele
Kwikstaart Motacilla ava ava,
Breskens, Zeeland, 26 April 2004
(Dick Groenendijk); 3 ‘British’
Yellow Wagtail / Engelse Kwik-
staart Motacilla avissima, Kenne-
mermeer, IJmuiden, Noord-
Holland, 28 April 2000 (Arnoud B
van den Berg); 4 ‘British’ Yellow
Wagtail / Engelse Kwikstaart
Motacilla avissima, Kennemer-
meer, IJmuiden, Noord-Holland,
20 April 2003 (Magnus Robb/The
Sound Approach; 03.010.MR.04705.11); 5-6 Grey-headed Wagtail / Noordse Kwikstaart Motacilla thunbergi,
Eemshaven, Groningen, 16 May 2003 (Dick Groenendijk). Horizontal line at 7 kHz added to facilitate comparison of
ight calls. Note decreasing space between both lines of part 1 with increasing pitch, in these ight calls. All calls are
very similar with smooth part 2.
0.2 0.6 s
kHz
1.0
5.0
6.0
4.0
3.0
2.0
0.4 0.8 1.0
7.0
8.0
9.0
0.2 s
kHz
1.0
5.0
6.0
4.0
3.0
2.0
0.4
7.0
8.0
9.0
s
0.2
kHz
1.0
5.0
6.0
4.0
3.0
2.0
0.4
7.0
8.0
9.0
1 2
A B
FIGURE 2 Typical song of male ‘British’ Yellow Wagtail /
Engelse Kwikstaart Motacilla avissima, Oostvaarders-
plassen, Lelystad, Flevoland, 21 May 2005 (Dick
Groenen dijk). This song type is common in all north-
western taxa. Other taxa, especially eastern and south-
western, may have different songs than depicted here.
FIGURE 3 A Flight call of male Black-headed Wagtail /
Balkankwikstaart Motacilla feldegg, Shardara Reservoir,
Kazakhstan, 6 April 2011 (PatrickFranke;XC120527).
Note bisyllabic structure. Part one concerns shorter,
sharply rising syllable with a left and a right line. The
latter shows a distinct thick hook between 3 and 4 kHz
in south-western taxa. In eastern and north-western taxa,
this hook is absent and both lines increase straight or
slightly concave and run roughly parallel. Part two is a
longer and descending syllable. This part has a ‘saw-
tooth’ shape in south-western and eastern taxa, as in this
feldegg, whereas it is smooth in north-western taxa.
B Single song phrase of male ‘British’ Yellow Wagtail /
Engelse Kwikstaart Motacilla avissima, Oostvaar ders-
plassen, Lelystad, Flevoland, 21 May 2005 (Dick
Groenendijk).
0.2 0.6 s
kHz
1.0
5.0
6.0
4.0
3.0
2.0
0.4 0.8 1.0
7.0
8.0
9.0
1.2 1.6
1.4 1.8
1 2 345 6
EasternyellowwagtailsinEurope:identicationandvocalisations
yellow wagtails is visible in the saw-like shape of
this descending, second part. An example of a
ight call of feldegg is given in gure 3a.
North-western taxa
Flight calls of the north-western taxa avissima,
ava, beema and thunbergi can be described as a
ne, high-pitched psiee or tsliee. The ight call
shows a steep rising rst part which is visible in
sonagrams as a double line of which the right one
is the most pronounced. The left line is less visible
and almost absent below 4 kHz. The shape of the
right line is straight or slightly concave. With in-
creasing frequency there is a decrease in space
between both lines. The second part of the ight
call is visible in sonagrams as a rather solid and

305
smooth descending line. It starts at c 8 kHz, stays
at this frequency for a short time and then drops
steeply in pitch. Most energy is in this second part
of the ight call, as is visible from the ‘blackness’
of that part of the sonagram. No saw-like struc-
tures are present, although rarely one small peak
can be seen at c 6 kHz. Sonagrams of avissima,
ava and thunbergi are shown in gure 4. Beema
has a ight call similar to other western taxa (g-
ure 5).
South-western taxa
Flight calls of cinereocapilla, iberiae and feldegg
differ from the western taxa in two aspects. The
most important difference is the saw-like structure
of the descending, second, part which creates the
rasping quality of the ight call. The number of
individual ‘teeth’ and their spacing is variable but
normally numbers between two and six. If the
number of ‘teeth’ is low, the ight call sounds
much less rasping in the eld. The bandwidth of
‘teeth’ in the descending part is large, c 3 kHz,
especially in cinereocapilla and iberiae (gure 6).
The second difference is visible in the rising
part of the ight call. The right line normally shows
a distinct hook (roughly 45º towards left-hand
corner) between roughly 3 and 5 kHz which is
absent in taxa of the north-western and the east-
ern group (Magnus Robb pers comm). Sonagrams
of ight calls of cinereocapilla, iberiae and feldegg
are presented in gure 6. Note that the second
part in cinereocapilla and iberiae is roughly hori-
zontal compared with the more descending sec-
ond part in feldegg. Sonagrams of cinereocapilla
and iberiae appear ‘square’ (the rasping part has
roughly a time-duration similar to the frequency-
amplitude, ‘as broad as high’) compared to the
more slender and elongate feldegg. Whether this
is a consistent difference between these taxa
needs more study
Eastern taxa
Typical ight calls of the eastern taxa plexa,
tschutschensis, taivana and macronyx are quite
similar in structure and have characteristics of
both the north-western and the south-western
group. The rising rst part is rather straight and is
supercially similar to the rising part in ight calls
of the north-western group. Note, however, that
both lines of the rst part run closely together at
lowest pitch but farther apart with increasing
pitch. In taxa of the north-western group, both
lines may approach each other closely at the high-
est pitch of the rst part, basically the other way
around. Whether this difference is consistent be-
tween congeners of both groups needs more study.
The descending second part shows a distinct saw-
like structure as in ight calls from congeners of
the south-western group. However, the vertical
depth of the saws in the descending part is less
pronounced and c 2 kHz. Furthermore, taivana
and macronyxtend to show more teeth in part two
than is shown in ight calls of south-western taxa.
Sonagrams of ight calls of plexa, tschutschensis,
taivana and macronyx are shown in gure 7-8.
The ight call of taivana tends to be a bit lower
compared with ight calls of other eastern taxa.
The variation in ight calls of these eastern spe-
cies remains poorly understood. A genetically
proven eastern yellow wagtail present in Ireland
in October 2013 (http://birdingfrontiers.com;
plate 406) not only had a rasping ight call but
also used a ight call similar to that of north-west-
ern birds. In addition, a possible eastern yellow
wagtail present in October 2011 at Foz de Sizan-
dro, Portugal, used both types of ight call
(Magnus Robb pers comm), which is also true for
possible eastern yellow wagtails on Vlieland,
Friesland, the Netherlands, in 2009 and 2011. In
most cases, at take-off, a typical raspy ight call
was given but this raspiness became less when
more ight calls were given. The last ight calls of
a series usually showed no saws in the descending
part and looked similar to ight calls of north-
western birds.
FIGURE 5 Flight calls of four different individuals of
Sykes’s Blue-headed Wagtail / Russische Gele Kwikstaart
Motacillaavabeema: 1 Akmola, Kazakhstan, 17 May
2013 (Thijs Fijen; XC145123); 2-3 Akmola, Kazakhstan,
3 May 2013 (Thijs Fijen; XC145073, XC145074);
4 Shapsha, Khanty-Mansiyskiy Autonomous Okrug,
Russia, 15 June 2009 (HermanvanOosten;XC153006).
Horizontal line at 7 kHz added to facilitate comparison
of ight calls. Note similarity of beema ight calls to
avissima, ava and thunbergi.
0.2 0.6 s
kHz
1.0
5.0
6.0
4.0
3.0
2.0
0.4 0.8 1.0
7.0
8.0
9.0
1.2
1 2 34
EasternyellowwagtailsinEurope:identicationandvocalisations

306
FIGURE 7 Flight calls of
taxa belonging to eastern
group: 1-4 Alaskan Wag-
tail / Alaskakwikstaart Mo-
ta cilla tschutschensis, Bys-
trinsky District, Kam chatka
Krai, Russia, 6 July 2012
(Adria Sole; XC113757,
XC113759); 5-6 Siberian
Wag tail / Siberische Kwik-
staart Motacilla plexa, No-
ya brsk, Yamalo-Nenets kiy
Auto nomous Okrug, Rus-
sia, 23 June 2009 (Herman
van Oosten; XC153011).
Horizontal line at 7 kHz added to facilitate comparison of ight calls. Note ascending part 1 is quite similar to north-
western group but spacing between both lines of part 1 slightly different: close together at lowest pitch but widening
with increasing pitch. Part 2 resembles south-western group; however, note absence of distinct hook in rst part.
Citrine Wagtail
Flight calls of Citrine Wagtail sound like an explo-
sive, sharp and harsh tsreep and sound super-
cially much like ight calls of south-western and,
especially, eastern taxa. The rst part is straight,
less clearly double-lined and both lines of the rst
part run parallel and closer to each other than in
the congeners of the eastern and, especially, the
south-western group. The left line of this rising
part is rather faint or absent in most ight calls. It
also starts at a higher pitch, at c 3 kHz, which is
about the frequency where the descending part
ends. The descending second part is falling less
steep compared with ight calls of yellow wagtail
taxa, which is especially visible in the rst part of
the descending leg. The sonagram of Citrine’s
ight call, therefore, looks more like an ‘n’ with
the two legs rather equal in length, and less like
the pointed inverted ‘v’ in yellow wagtail taxa.
The saw-like structure of the descending leg con-
sists of more saws. However, these saws are less
deep and, therefore, less clear. This creates more
of a harsh buzz of the ight call compared with all
south-western taxa and the eastern taxa plexa and
tschutschensis. In a sonagram this is visible as a
solid, energy-rich part. Sonagrams of Citrine are
shown in gure 9.
Reports in the Netherlands
At the moment, there are six claims of eastern yel-
low wagtail in the Netherlands supported by pho-
tographs and/or sound recordings (table 4). All
birds were seemingly on active migration and dis-
appeared within a day. All reports concern rst-
FIGURE 6 Flight calls of
taxa belonging to south-
western group: 1 Ashy-
headed Wagtail / Itali aanse
Kwikstaart Mota cilla cine-
reocapilla cine reo capilla,
Osa river, Orbetello, Italy,
6 June 2004 (Marco Dra-
go netti; XC54042); 2
Ashy- head ed Wagtail /
Itali aanse Kwikstaart Mo-
ta cilla cinereocapilla cine-
reocapilla, Diaccia Botro-
na marsh, Casti glione del-
la Pescaia, Italy, 21 June
2010 (Marco Dragonetti; XC67349); 3-4 Spanish Wagtail / Iberische Kwikstaart Motacilla cinereocapilla iberiae,
Ouarzazate, Morocco, 6 November 2009 (FerryOssendorp); 5-6 Black-headed Wagtail / Balkankwikstaart Motacilla
feldegg, Shardara Reservoir, Kazakhstan, 6 April 2011 (PatrickFranke; XC120527, XC120328). Horizontal line at
7 kHz added to facilitate comparison of ight calls. Note difference from north-western group with clear saw-like
structure in part 2 of call and a distinct hook in part 1 (right line, between 3-5 kHz).
g6
0.2 0.6 s
kHz
1.0
5.0
6.0
4.0
3.0
2.0
0.4 0.8 1.0
7.0
8.0
9.0
1.2 1.6
1.4 1.8 2.0
1 2 345 6
0.2 0.6 s
kHz
1.0
5.0
6.0
4.0
3.0
2.0
0.4 0.8 1.0
7.0
8.0
9.0
1.2 1.6
1.4 1.8 2.0
1 2 345 6
EasternyellowwagtailsinEurope:identicationandvocalisations

307
FIGURE 9 Flight calls of Citrine Wagtail /
Citroenkwikstaart Motacilla citreola. 1-2
Saldi pond, Amreli, India, 8 February 2012
(VirJoshi;XC98665); 3-4 Barr al Hikman,
Oman, 16 December 2012 (Thijs Fijen;
XC118181); 5-6 Ooijpolder, Nijmegen,
Gelderland, 23 August 2008 (Dick
Groenendijk). Horizontal line at 7 kHz
added to facilitate comparison of ight
calls. Note blunt-tipped ‘n’ shape of ight
call where both legs are similar in length.
Left and right lines of part one run parallel
and close to each other. Note characteris-
tic solid appearance of part two.
FIGURE 8 Flight calls of taxa belonging to
eastern group: 1 Manchurian Wagtail /
Mantsjoerijse Kwikstaart Motacillamacro-
nyx, Kiat Ngong, Laos, 20 December 2008
(Wouter Halfwerk; XC27241); 2-3 Man-
chu rian Wagtail / Mantsjoerijse Kwikstaart
Motacillamacronyx, Phnom Krom marsh,
Siem Reap, Cambodia, 13 March 2013
(Frank Lambert; XC127900, XC127898);
4-5 Green-headed Wagtail / Groenkop-
kwikstaart Motacilla taivana, Shanhua,
Taiwan, 21 February 2008 (Sander Bot;
XC65415,XC65416). Horizontal line at 7
kHz added to facilitate comparison of
ight calls. Note ascending part 1 is quite
similar to north-western group but spacing
between both lines of part 1 slightly different: close together at lowest pitch but widening with increasing pitch.
Part 2 resembles south-western group; however, note absence of distinct hook in rst part.
0.2 0.6 s
kHz
1.0
5.0
6.0
4.0
3.0
2.0
0.4 0.8 1.0
7.0
8.0
9.0
1.2 1.6
1.4
10.0
1 2 345 6
0.2 0.6 s
kHz
1.0
5.0
6.0
4.0
3.0
2.0
0.4 0.8 1.0
7.0
8.0
9.0
1.2 1.6
1.4
1 2 345 6
EasternyellowwagtailsinEurope:identicationandvocalisations
406 North-eastern yellow wagtail / Siberische/Alaskakwikstaart Motacilla plexa/tschutschensis, rst-year, Tory Island,
Donegal, Ireland, October 2013 (Aidan Kelly). Either plexa or tschutschensis based on DNA. A classic monochrome
grey-and-white bird.

308
EasternyellowwagtailsinEurope:identicationandvocalisations
year birds in late autumn, except one in September.
In four cases, there are both sound recordings and
photographs (remarkably all from Vlieland). For
one report there is only a sound recording and for
one other report there are only photographs. From
none of the reports, feathers or faeces were col-
lected for DNA analysis. The September 2009 bird
on Vlieland is morphologically interesting since
this bird showed characters tting both yellow
wagtail and Citrine Wagtail. The dark lore, narrow
wing-bars, some yellow on undertail-coverts, and
uppertail-coverts with dark centre indicate yellow
wagtail. However, the brownish forehead, ‘hol-
low-centred’ ear-coverts, completely whitish-
framed ear-coverts, black tertial centre and black
bill base t Citrine better. Since the ight call was
similar to eastern yellow wagtail it is well possible
that this bird is an eastern yellow wagtail exempli-
fying the variability of eastern taxa.
Discussion
We found indications, albeit sample sizes are ad-
mittedly low, that north-western taxa of yellow
wagtails (avissima, ava, beema and thunbergi),
south-western taxa (cinereocapilla, iberiae and fel-
degg), eastern taxa (plexa, tschutschensis, taivana
and macronyx) and Citrine Wagtails can be distin-
guished based on their ight calls. It should how-
ever be emphasized that due to the variation,
good recordings of preferably multiple ight calls
TABLE 4 Reports of eastern yellow wagtails Motacilla in the Netherlands for which documentation is
available. See also plate 407-409 and gure 10.
Date Location Documentation Notes
29-10-2005 Maasvlakte, Rotterdam, sound recording sound recording shows eastern yellow wagtail
Zuid-Holland
13-10-2008 Vlieland, Friesland photographs and sound recording shows eastern yellow wagtail
sound recording
20-09-2009 Vlieland, Friesland photographs and some eld characters t Citrine Wagtail better;
sound recording called like eastern and north-western yellow
wagtail
22-10-2011 Vlieland, Friesland photographs and called both like eastern and north-western yellow
sound recording wagtail; only call on recording is like north-western
28-10-2011 Bergen aan Zee, photographs and rasping call heard but not recorded; photographs
Noord-Holland eld sketch show bird without yellow in plumage
21-10-2012 Vlieland, Friesland photographs and photographs and sound recordings show classic
sound recording eastern yellow wagtail
407 Yellow wagtail / gele kwikstaart Motacilla, rst-
year, Vlieland, Friesland, Netherlands, 20 September
2009 (BasvandenBoogaard)
408 Yellow wagtail / gele kwikstaart Motacilla, rst-
year, Vlieland, Friesland, Netherlands, 22 October
2011 (MarijnvanOss)

309
EasternyellowwagtailsinEurope:identicationandvocalisations
FIGURE 10 Yellow wagtail / gele kwikstaart Motacilla, rst-year, Bergen aan Zee, Noord-Holland, Netherlands,
28 October 2011 (Frits-Jan Maas)
are needed to identify single vagrant birds outside
their normal range. Furthermore, it is very impor-
tant to judge the described differences on what
we dened as a ight call in this paper (gure 3),
because the variation in calls in yellow wagtails is
large and alarm calls or contact calls from one
taxon may supercially sound similar to ight
calls from another taxon. Variation in calls is espe-
cially large on the breeding grounds. Also adver-
tising males may include call-like elements in
their song which can sound different from their
normal ight call.
Identifying ight calls of north-western taxa is
pretty much straightforward: avissima, ava, bee-
ma and thunbergi all have very smooth ight calls
without a distinct saw-like second part in the
sona gram. All other taxa show this saw-like sec-
ond part albeit with variation in shape, duration
and teeth density. Yet, identifying harsh-calling
yellow wagtails is not too problematic to the level
of group, at least to the south-western group
(cine reocapilla, iberiae and feldegg), eastern group
(plexa, tschutschensis, taivana and macronyx) or
Citrine Wagtail, given that good recordings of
ight calls are provided.
Flight calls of south-western taxa show a dis-
409 Yellow wagtail / gele kwikstaart Motacilla, rst-
year, Vlieland, Friesland, Netherlands, 21 October
2012 (Lars Buckx)

310
EasternyellowwagtailsinEurope:identicationandvocalisations
tinct, thick hook in the right line of the rst part of
the sonagram, roughly between 3-5 kHz, with an
obvious broader bandwidth than the rest of this
line. This feature distinguishes this group from the
equally harsh sounding eastern taxa. Citrine
Wagtail is distinctive by a combination of closely
spaced and parallel running lines of the rst part,
teeth-density, pitch and the smooth curve down of
the second part. Flight call variation within the
groups is less clear (little studied) but ‘taxon spe-
cic’ differences may exist, for example between
cinereocapilla/iberiae and feldegg of the southern
group. Also variation between members of the
eastern group may exist but sample sizes are yet
too small to suggest any.
Conclusion
Records in Britain and Ireland show that eastern
yellow wagtail can occur in western Europe. A
monochrome grey-and-white plumage as shown
in many rst-winter eastern yellow wagtails great-
ly increases the chance of detecting a vagrant
eastern yellow wagtail, since this plumage is very
rare in western species. A long hind claw and an
occurrence late in autumn are other indications
that the bird is an eastern yellow wagtail. When a
rasping ight call is heard, the bird is denitely
not a north-western taxon, and in this way even a
not grey-and-white eastern yellow wagtail can be
picked out. The ight calls need to be recorded to
distinguish further between Citrine Wagtail, the
south-western taxa and eastern yellow wagtail.
Within eastern yellow wagtail, DNA analysis is
needed to distinguish birds from the north-eastern
clade (plexa and tschutschensis) and the south-
eastern clade (taivana and macronyx). Within
eastern yellow wagtail, plexa is probably the most
likely vagrant, simply based on range: it occurs at
least as far west as Yamal, Russia, close to the
Western Palearctic border (Pavlova et al 2003;
gure 1).
Acknowledgements
The authors would like to thank the following
people who helped in various ways with improv-
ing the paper: Raül Aymí, Arnoud van den Berg/
The Sound Approach, Marco Dragonetti, Thijs
Fijen, Patrick Franke, Wouter Halfwerk, Vir Joshi,
Frank Lambert, Ferry Ossendorp, Magnus Robb/
The Sound Approach and Adria Sole.
Samenvatting
OO s t e l i j k e g e l e k w i k s t a a r t e n in eu r O p a : h e r k e n n i n g en
g e l u i d e n Dit artikel gaat in op de determinatie van eer-
ste-winter oostelijke gele kwikstaart Motacilla, waartoe
een aantal taxa binnen het gele-kwikstaartcomplex uit
Azië wordt gerekend: Siberische Kwikstaart M plexa,
Alaskakwikstaart M tschutschensis, Groenkopkwikstaart
M taivana en Mantsjoerijse Kwikstaart M macronyx.
Deze taxa kunnen als dwaalgast in Europa opduiken.
De taxonomische status van plexa is problematisch.
Morfologisch lijkt hij zo sterk op Noordse Kwikstaart
M thunbergi dat hij tot voor kort als synoniem van thun-
bergi werd opgevat. Recentelijk bleek echter dat hij ge-
netisch zo sterk lijkt op tschutschensis dat hij als onder-
soort van tschutschensis kan worden beschouwd. In dit
artikel krijgt plexa soortstatus, wat in lijn is met andere
CSNA-beslissingen over kwikstaarten in het verleden. Er
is meer onderzoek nodig aan dit taxon om de taxonomi-
sche status te bepalen.
In het najaar is een eerste-winter doorgaans van een
adult te onderscheiden door de ongeruide juveniele ter-
tials en grote en middelste dekveren. Deze veren heb-
ben wittere en scherper afgetekende randen dan adulte
veren. Oostelijke gele kwikstaarten hebben gemiddeld
een langere achternagel dan noord-westelijke taxa maar
er is overlap. Hoewel het vaak geheel grijs-met-wit ve-
renkleed lijkt op eerste-winter Citroenkwikstaart M ci-
treola verschillen oostelijke gele kwikstaarten door:
1 een meestal lichte basis van de ondersnavel; 2 minder
brede witte vleugelstrepen; en 3 geen geheel licht om-
rande wang. Een complicerende factor vormen hybriden
Citroenkwikstaart x gele kwikstaart (er is een aantal
broedgevallen gedocumenteerd in Europa), die in mor-
fologie vermoedelijk sterk op oostelijke gele kwikstaart
kunnen lijken.
Het ontbreken van geel in het kleed is bij eerste-win-
ters van taxa in Europa zeer zeldzaam, terwijl dit kleed
bij oostelijke gele kwikstaarten bij een derde tot de helft
van de individuen voorkomt. Hierdoor is een grijswit
kleed bij eerste-winter vogels een goede indicatie voor
oostelijke herkomst. Met de huidige kennis is het nog
niet goed mogelijk op basis van morfologie de verschil-
lende taxa binnen oostelijke gele kwikstaart in eerste
winterkleed van elkaar te onderscheiden.
De vluchtroep van oostelijke gele kwikstaarten is het
belangrijkste kenmerk. Een gele-kwikstaartroep bestaat
uit twee delen: een stijgend, ‘glad’ deel en een dalend
deel. Dit dalende deel is ook ‘glad’ bij noord-westelijke
taxa (Engelse Kwikstaart Mavissima, Gele Kwikstaart
M ava (inclusief Russische M f beema) en Noordse
Kwikstaart) maar heeft een ‘zaagtandvorm’ bij oostelijke
gele kwikstaart, waardoor dit deel (maar in feite de
vluchtroep als geheel) raspend klinkt. Bij Witkeel-
kwikstaart M cinereocapilla en Balkankwikstaart M fel-
degg heeft het dalende deel ook een zaagtandvorm
maar is in de regel een knikje waarneembaar in het stij-
gende eerste deel. De vluchtroep van Citroenkwikstaart
heeft ook een zaagtandvorm in het dalende deel en
klinkt dus ook raspend maar de vorm verschilt subtiel
van oostelijke gele kwikstaart. Omdat de zang van het
gehele gele-kwikstaartcomplex ook raspende geluiden
bevat, is het van belang vluchtroep en zang te onder-
scheiden, temeer daar zangelementen niet alleen in het
broedgebied worden gebruikt. De vluchtroep verschilt
van zang doordat de roep: 1 korter is; 2 de zaagtand-

311
EasternyellowwagtailsinEurope:identicationandvocalisations
structuur op het tweede, dalende gedeelte van de vlucht-
roep meer geprononceerd is; en 3 het eerste, stijgende
deel van de vluchtroep complexer is.
Taxa met een raspende vluchtroep zijn op grond van
sonagrammen goed van elkaar te onderscheiden en oos-
telijke gele kwikstaart is op grond van goed opgenomen
vluchtroepen als zodanig te herkennen.
In Nederland zijn zes meldingen (‘claims’) van ooste-
lijke gele kwikstaart die zijn onderbouwd met foto’s en/
of geluidsopnamen en die in dit artikel worden behan-
deld. Omdat Siberische Kwikstaart (plexa) tot oostelijke
gele kwikstaart wordt gerekend en volgens recent on-
derzoek al direct ten oosten van de Oeral, Rusland,
broedt, ligt het voor de hand dat recente meldingen van
oostelijke gele kwikstaart op dit taxon betrekking heb-
ben maar met name ook Alaskakwikstaart (tschutschen-
sis) behoort op basis van afstand en trekgedrag tot de
mogelijkheden.
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