Ageing and sexing the Ringed Plover Charadrius hiaticula

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99
INTRODUCTION
Within Ringed Plover three subspecies are recognized: Char-
adrius hiaticula hiaticula breeds in S Scandinavia, the Baltic
countries, Britain, Ireland, France and south to Central and
Western European. C. h. tundrae nests from N Scandinavia
to the easternmost parts of N Russia. C. h. psammodroma has
breeding grounds in NE Canada, Greenland, Iceland and the
Faeroes. The main wintering grounds of the species extend
from the British Isles south to Africa and to the east to the
Red Sea and Persian Gulf (Glutz von Blotzheim et al.1975,
Hayman et al. 1987, Cramp & Simmons 1983). The Ringed
Plover has one of the classic examples of leap-frog migra-
tion in which birds from more southerly populations winter
close to the breeding grounds and those from northernmost
parts of the breeding range make long ights to more distant
wintering grounds (Salomonsen 1955). The tundrae subspe-
cies migrates in autumn across the continental land masses of
Eurasia and Africa, whereas hiaticula moves towards W Eu-
ropean and N African wintering grounds mainly along the
coasts (Glutz von Blotzheim et al.1975, Cramp & Simmons
1983). However, a proportion of hiaticula birds breeding
inland in Poland also migrates SW to S across the continent
(P. Chylarecki unpub. data). In Central Europe, hiaticula
migrate earlier, with many local breeders usually leaving
the breeding grounds in mid July, and the vast majority of
adults observed from the beginning of August belong to the
tundrae subspecies. In the case of juveniles, the proportion
of these two subspecies change more gradually in August
(Meissner 2007). C. h. hiaticula is generally larger and paler
than C. h. tundrae, but this division is unsatisfactory, because
the variation in distinguishing features, i.e. size and the colour
of the upperparts (tundrae being smaller and darker) is rather
clinal (Prater et al. 1977, Hayman et al. 1987). Furthermore,
tundrae from Central Siberia are again larger, approaching
hiaticula in size (P. Chylarecki unpub. data).
Data presented here are based on the literature (Kozlova
1961, Glutz von Blotzheim 1972, Glutz von Blotzheim et
al. 1975, Prater et al. 1977, Hayman et al. 1987, Holz 1987)
and the authors’ own experience with Ringed Plovers breed-
ing and migrating through Europe. Therefore the ageing and
sexing criteria we describe should be applied to other Ringed
Plover populations with caution.
MOULT SCHEDULE
The sequence of moult is similar to other small plovers breed-
ing in the northern hemisphere. However hiaticula and tun-
drae differ in the timing of their moult (Fig. 1). In hiaticula,
juvenile plumage is replaced by rst winter plumage from
August (at the earliest) until January. Only a few juvenile
inner median coverts remain after this post-juvenile moult.
Ageing and Sexing Series*
* This series summarising current knowledge on ageing and sexing waders is co-ordinated by Włodzimierz Meissner (address
above). See Wader Study Group Bulletin Vol 113 p. 28 for the Introduction to the series.
Part 7: Ageing and sexing the Ringed Plover Charadrius hiaticula
WŁODZIMIERZ MEISSNER1, PRZEMYSŁAW CHYLARECKI3 & MICHAŁ SKAKUJ2
1Avian Ecophysiology Unit, 2Vertebrate Zoology Unit, Department of Vertebrate Ecology & Zoology,
University of Gdańsk, Al. Legionów 9, 80-441 Gdańsk, Poland. w.meissner@univ.gda.pl
3 Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00-679 Warsaw, Poland
Meissner, W., Chylarecki, P. & Skakuj, M. 2010. Ageing and sexing the Ringed Plover Charadrius hiaticula.
Wader Study Group Bull. 117(2): 99–102.
Keywords: Ringed Plover Charadrius hiaticula, ageing, sexing
Fig. 1. Moult schedule of Ringed Plover in the subspecies hiaticula and tundrae. P = primaries; BF = body feathers; MC = median wing
coverts; Black = juvenile feathers; grey = non-breeding plumage; white = breeding plumage; black broken line = presence of retained juvenile
inner median coverts (but not in all individuals).
C. h. hiaticula
C. h. tundrae

100 Wader Study Group Bulletin 117 (2) 2010
These may be retained until the following summer, but later
in the season they become very worn and difcult to recog-
nize. Juvenile primaries are replaced in the autumn of the
second calendar year of life. In tundrae, juveniles carry out
a complete moult of body plumage and coverts which usually
starts on the wintering grounds. A few juvenile feathers may
be recorded until January. Juvenile primaries are moulted
during the rst winter and spring.
In tundrae, breeding plumage is attained in February and
March in a partial pre-breeding moult, but in hiaticula only
a few feathers are replaced in this moult. Hence, winter and
breeding plumages look similar in hiaticula. The timing of the
post-breeding moult varies between different populations. In
most hiaticula, moult starts on the breeding grounds, where
it involves the inner primaries and some body feathers. The
primaries are replaced between late June and October, but
mostly starting in July (Walters 1984). Single mantle feathers
and tertiaries are often replaced starting from May. In tundrae,
primary moult starts in November on the wintering grounds.
Thus, birds caught during autumn migration with moulting
primaries are hiaticula.
AGEING
Juvenile plumage
Juveniles lack the black and white head and breast pattern
of adults. The feathers of the upperparts are brown with pale
bufsh fringes and a faint darker sub-terminal band which
is parallel to the feather edge (Fig. 2). This pattern is more
distinct on the scapulars than on the wing coverts. The bill is
dark with yellowish at the base of lower mandible (Fig. 3).
First winter non-breeding plumage
Differs from adult non-breeding by presence of retained juve-
nile inner median coverts and scapulars which have a bufsh
fringe and dark, thin sub-terminal band. An additional feature
in hiaticula is primary wear. Primaries are more worn in juve-
niles than in adults in non-breeding plumage (but see below).
In tundrae, the primaries and wing coverts are moulted during
winter and these birds become impossible to age by January.
First breeding plumage
Some individuals of hiaticula may retain juvenile inner
medians and this is the only reliable feature indicating age.
The majority of these birds have very worn primaries and a
clear contrast between pale and faded tips and feather centres,
which is clearly visible on the 7th and 8th primaries (Holz
1987). However, a proportion of rst-year hiaticula renew
their outermost primaries, and these birds can be recognized
juvenile worn adultfresh adult
Fig. 2. Inner median coverts of Ringed Plovers: juvenile, adult in fresh and adult in worn plumage. (Drawings by Michał Skakuj.)
as such because of the contrast between 3–5 fresh outer and
worn inner primaries (and sometimes a few unmoulted juve-
nile median coverts). In tundrae, birds in their rst breeding
plumage cannot be distinguished, as they undergo a complete
moult (including primaries and inner medians) during their
rst winter.
Adult breeding plumage
Characteristic head pattern with black or blackish-brown
markings (Fig. 3). The bill is orange with a black tip. In
fresh plumage, the median coverts have very narrow, whitish
fringes (Fig. 2), but – in contrast to retained juvenile feathers
in rst breeding plumage – no dark sub-terminal band. When
these fringes are worn (Fig. 2), the upperparts look uniformly
brown. This plumage is attained in hiaticula in late autumn,
whereas in tundrae it is attained in spring, during the pre-
breeding moult.
Adult non-breeding plumage
In hiaticula, there is no distinct non-breeding plumage and
adults have similar plumage year round. In tundrae, the black
feathers within the dark head and breast bands are replaced
by brown or blackish-brown feathers. The basal part of the
bill becomes duller than during the breeding season (Fig. 3).
Distinctive juvenile inner medians are retained in all rst
year birds until December so ageing them in early autumn
should straightforward (EURING ringing code: 3). The only
certain means of identifying birds in their rst winter or rst
breeding plumage is the presence of retained juvenile inner
median coverts or heavily worn primaries (including birds in
which only the inner primaries are worn, the outer primaries
having been renewed) (EURING ringing codes: up to 31
December: 3, after 31 December: 5). Ringed Plovers of the
tundrae subspecies do a complete moult of all juvenile coverts
and primaries in late autumn and early winter. Therefore birds
with no juvenile inner medians cannot be aged reliably in
winter, i.e. they could be either adult or rst-year (EURING
ringing codes: up to 31 December: 2, after 31 December: 4).
Among birds in breeding plumage, attention should be paid
to the presence of juvenile inner median coverts indicating
a bird in its rst breeding plumage (EURING ringing code:
5); such birds should also have very worn primaries – usually
all primaries, but sometimes only the inner ones. However,
it should be borne in mind that distinguishing birds in rst
breeding plumage is possible in only some hiaticula. Other
birds in breeding plumage, with no sign of juvenile feathers
have to be aged as ‘older than 1 year’ (EURING ringing code:
4), although the majority of hiaticula with uniformly and
moderately worn primaries are probably (but not certainly)
older than 2 years (EURING ringing code: 6).

101
Ageing and Sexing Series: Ringed Plover
breast and ear coverts are females (P. Chylarecki unpub. data).
In the breeding season, the orbital ring of the eye in males
is yellow to yellow-orange, whereas in most females it is grey,
though some have a small yellow patch in the corner of the
eye. Also, the black tip of the bill is sharply dened in males,
but the border between the black and orange is somewhat
diffuse in most females (Fig. 3).
Some breeding females can show a continuous, white su-
percilium running above the eye and joining the white frontal
patch with a white line above the ear coverts. However, late
in the breeding season (July), some males can also show
some single white feathers above the eye, probably a result
of advanced feather wear.
Generally, sexing is quite straightforward, but only in
breeding plumage. Within a pair, the differences in head
markings (especially in the amount of black on the ear
coverts) and the orbital ring colour are easy to recognize
(Fig. 3). Single birds caught during the breeding season or at
the beginning of autumn migration (i.e. in Jul–Aug) should be
sexed with caution, but individuals with <90% black in the ear
coverts and breast band and lacking a bright orbital ring may
be sexed as females with condence. Positive identication of
males is less safe as some “very black” birds can be females
(although they form a small percentage of this group). There
are no known characteristics for sexing Ringed Plovers in
non-breeding plumage.
Fig. 3. Head and breast pattern of Ringed Plovers. Two types of adult females are shown: typical and extremely pale. (Drawings by Michał Skakuj.)
SEXING OF ADULTS IN BREEDING PLUMAGE
Linear measurements of male and female Ringed Plovers
have a large overlap in all subspecies, so biometrics cannot
be used to sex birds, even within breeding pairs. The head
markings and a breast band of adult males are deeply black
or with only a few brown feathers at the sides of the band
and in the ear coverts. Females typically have narrower bands
across the breast and crown and browner ear coverts than
males. According to Taylor (1974), in May, June and July the
mean percent of brown feathers in the sides of the breast band
in males is <4%, whereas in females it is at least 20%. Data
from the Polish breeding population are consistent with this
in that black feathers comprised 90–100% of the breast band
in 93% of males but in <30% of females. The percentage of
black feathers in the ear coverts is an even better guide: al-
most all (99%) males had 90–100% black feathers, compared
to 18% of females. Additionally, the black band across the
crown is narrower in females (average 6.7 mm) than in males
(8.0 mm), but the overlap is quite extensive. However, 75% of
females have this band not wider than 7.3 mm, while 75% of
males show a black band of at least 7.4 mm width. Therefore,
generally birds with noticeable amount of brown feathers in
the ear coverts and breast band can be safely classied as
females, but the converse is not true – a (small) fraction of
individuals scored as having 90–100% black feathers on the

102 Wader Study Group Bulletin 117 (2) 2010
ACKNOWLEDGEMENTS
Studies on the Polish breeding population of Ringed Plover
were supported by grants 4-1637-91-01, 6-P04F-043-12,
6-P04G-098-21, PBZ-KBN-087-P04-2003 from the Ministry
of Science Research and Information Technology to P. Chy-
larecki. We thank Bob Swann for comments on a draft.
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Ringed Plovers Charadrius hiaticula,
German Wadden Sea, 18 April 2005.
(Photos by Jan van de Kam.)