Bird Research News

Vol.8 No.2

White-cheeked Starling
Morphology and classification
Classification: Passeriformes Sturnidae
Total length:
238mm (225-243)
Wing length: ♂ 128.9±2.8mm ♀ 124.9±2.6mm
Tail length:♂ 65.9±2.2mm♀ 62.5±2.9mm
Culmen length: 26mm (24-27)
Tarsus length: 30mm (27-31)
Weight:23.0g (18.0-26.0)
Measurements after Enomoto (1941), except for the wing and tail lengths measured in
Sagamihara, Kanagawa Prefecture (♂ = 272, ♀ = 299) by the author.

Appearance:
Males and females are similar inplumage coloration. The back is darkbrown and the belly is gray. The
crown, wing and tail are tinged withblack. There is an irregular whitepatch from the crown to the cheek.
The bright orange leg and bill contrast sharply with the darker plumage. The white rump stands out wellwhen flying. In the breeding period,
the two-tone plumage become more
distinct and the leg and bill also increase in vividness in males. In females, on the other hand, the wholeplumage including the leg and bill isless vivid than males. The plumage
difference in the two sexes is discernible when they are perched side- Photo 1. Male (above) andapparently a female
by-side, but not so distinguishable(below).
when a bird is alone due to individual variation.

Vocalization:
White-cheeked Starlings have a wide variety of vocalization, ranging
from "Kyur-kyur" to "Jah-jah". A high-pitched call of Whitecheeked Starlings is used as one of the measures to expel them fromtheir urban roost (See “Roost”). This vocalization is called a "distresscall", which they utter when they are captured by a predator.

Distribution and Habitat
Distribution:
White-cheeked Starlings breed in Mongolia, the Russian Far East(Primorskii and Siberia) northern China, the Korean Peninsula andJapan, and winter in southern China, Taiwan and southeasternJapan. They are year-round residents in most regions of Japan, butthey are not abundant south of Kyushu (the southernmost mainisland). They used to be a summer resident in Hokkaido (the northernmost main island) and left the breeding grounds in autumn. In
recent years (at least after 2003), wintering birds have increased in
the southern and central areas of Hokkaido.

Habitat:White-cheeked Starlings occur in farmland, pastures, orchards,
woodlands around a village, parks, gardens and golf links fromlowlands to hills.

23

4 5 6 7breeding season

8 9 10 11 12
non-breeding season

Breeding system:
The breeding period is from late March to July. They breed onceor twice a year. Though they are generally monogamous,

4♪ http://www.bird-research.jp/1_shiryo/koe/mukudori_040529_fuchu_mju.mp3
Mutsuyuki Ueta

Mukudori (Jpn) Spodiopsar cineraceus
they rarely breed in polygamy. It is assumed that they may form apair before the breeding season starts because pair confirmation
behavior is observed in a wintering flock. Fierce disputes frequently arise over favorable nest sites in March. They establish theirbreeding territory within a several meter radius of a nest.

Nest:
White-cheeked Starlings build a nest in tree hollows in an open
wood, old nest holes of a woodpecker, shutter cases of a house,gaps in a tiled roof and a stone wall. They lay dead grass and fallen leaves in a nest and line an inner cup with feathers, fur, cellophane paper and fragments of nylon.

Egg:The clutch size is 4-7 eggs and larger inthe first breeding than in the secondbreeding. The egg is generally pale bluishgreen, but the coloration, size and shape
vary from one bird to another.

Photo 2. Eggs of Whitecheeked Starlings.

Incubation and nestling periods:
Both males and females incubate eggs, but females alone during
the night. Eggs hatch in about 12 days. Males and females feed
nestlings, which fledge about 23 days after hatching. Fledglings
spend about a month with their parents in a family flock. Whenthey become independent, they feed in a juvenile flock and form asummer roost with adult birds.

Roost:
The colonial roost of White-cheeked Starlings consists of a summer and winter roosts. A large flock of White-cheeked Starlings
presents a magnificent spectacle when they are circling the roostsite before going to roost in the evening from summer to autumn.
In summer they used to roost in bamboo grass thickets, coppices
and reed beds in suburban areas. In winter, on the other hand, theyused bamboo groves instead when reed beds were dead and coppices were bare of leaves. In recent years, however, they havestarted to use roadside trees as a summer roost in urban areas, andthey have caused friction with city dwellers because of their noiseand feces. Therefore, various measures have been adopted to drive
White-cheeked Starlings out of their roost. As a result, they havechanged their roost from deciduous trees to ever-green trees andfurther to man-made structures, such as billboards on top of buildings and electric wires. In addition, they have more frequently
come to use the same site as a roost in both summer and winter as
they shift their roost to man-made structures.

Diet and foraging behavior
White-cheeked Starlings are omnivorous. The diet include earthworms and insects as well as cherries (early summer), the seeds(autumn) of dogwoods, Sophora japonica and Ligustrum japonicum. They also eat peaches, pears, grapes, apples and persimmons,
but not Citrus fruits. In autumn and winter they visit farmland in alarge flock and insert the bill into the soil to forage for insects
walking on the ground.

Topics of ecology, behavior and conservation● Brood parasitism within species

Life history
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2011.2.21.

There are four parasitic bird species, such as Common Cuckoos(Cuculus canorus) and Lesser Cuckoos (C. policocephalus) in Japanthat parasitize other species nests. Some other birds, on the other
hand, deposit their eggs in their conspecific nests, which is called“intraspecific brood parasitism”. In this intraspecific parasitism,parasites also leave it to their hosts to incubate their eggs and raise
their nestlings. More than 200 bird species are known to commit

Bird Research News

Vol.8 No.2

2011.2.21.

© Japan Bird Research Association
Sumiyoshi 1-29-9, Fuchu, Tokyo, Japan

バードリサーチ生態図鑑

intraspecific brood parasitism in the world, but many more species
are suspected of intraspecific parasitism. White-cheeked Starlings
are known to be an intraspecific brood parasite in Japan. I set up 180
nest boxes to study the breeding ecology of White-cheeked Starlings
in a golf course in Sagamihara City, Kanagawa Pref., central Japan.
The study showed that intraspecific brood parasitism occurred inabout 20% of the nests, which was a relatively high rate among
intraspecific brood parasites. When parasites deposited their eggs inthe nest of the hosts which were at the egg-laying period, the parasitic eggs hatched in the same rate as those of the host and the parasite hatchlings fledged. The eggs deposited at the early incubation
stage (the first day), on the other hand, hatched later and therefore
the hatchlings were smaller than those of the hosts, with lower survival rate (fledging cases were few). The eggs deposited at the lateincubation stage did not hatch due to the shortage of incubation days
(Fig. 1). Parasites need to deposit their eggs when the hosts are atnumber of parasitic eggs

10unhatching
death after hatching
death at hatching
abandoned incubation
abandoned egg-laying
hatching

86420

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39

Egg-laying

Incubation

Nestling period

breeding stages of hosts

have generated friction with city-dwellers, which attracts more attention from the media from summer to autumn every year thantheir crop damage. In their roost sites of busy streets, for instance,measures such as the large-scale pruning and netting of roadsidetrees and the replay of their distress call have been adopted to drive
them away. However, they do not move to suburban areas but only
shift their roosts a short distance to nearby roadside trees, man-madestructures and the busy streets of neighboring towns. These efforts
often disperse their roost sites and exacerbate the situation. Although the municipality and residents of the original roost site may
be satisfied when White-cheeked Starlings move to other areas, thisis not the solution of the problem from a global point of view. It isonly a stopgap measure. Some municipalities have been recently
trying to find a way to coexist with White-cheeked Starlings byleaving less troublesome roosts alone, instead of expelling themthoroughly.

● Hybrid of White-cheeked Starlings and Red-billed Starlings
Fig. 1. The number and fate ofparasitic eggs at
each breeding
stage of the host(drawn after
Yamaguchi &Saitou 1997).

hatching rate (%)

the egg-laying stage. However, they also deposit their eggs in thenests of the hosts which are at the incubation stage, which suggeststhat they deposit their eggs opportunistically rather than in the appropriate time based on their careful observation.
It is assumed that brood parasitism has some effect on hosts because
they must incubate more eggs and raise more nestlings than theywould otherwise do. Thus I
100
compared hatching and80
fledging rates between
unparasitised and parasi60
tised pairs. There was nosignificant difference in40
hatching rate between then=631359
1220pairs, which suggests thatbrood parasitism has no0effect on the incubation of
non-parasitized parasitized non-parasitized parasitized
hosts. However, the fledghatching rate (%)
fledging rate (%)
ing rate was significantly
Fig. 2. The rates of hatching and fledgreduced in the parasitizeding in the parasitised and nonpairs, which shows thatparasitised nests (from Yamaguchi &brood parasitism has a great
Saitou 1997). Figures in bars show
impact on the chick-raising
the number of nests.
of hosts (Fig. 2).
It should be natural that White-cheeked Starlings remove deposited
eggs from the nest or defend the nest against brood parasites because brood parasitism may have a negative impact on the breeding
performance, but none of them were observed to take these countermeasures.
When I experimentally removed some of the nest boxes and deprived some pairs of their breeding opportunities, the proportion ofparasitized nests increased, which suggests that the pairs which
would otherwise breed normally deposit their eggs in the nests ofother conspecific pairs.

● Relationship of White-cheeked Starlings to people
White-cheeked Starlings were once considered to be a useful bird
because they ate a large amount of insect pests. Since the 1960s,
however, they have started to inflict damage on fruits such as pears,and therefore they are generally regarded as a pest bird nowadays.
In recent years, White-cheeked Starlings roosting in urban areas

In addition to White-cheeked Starlings, Sturnidae is represented inJapan by Chestnut-cheeked Starlings (Agropsar philippensis), Redbilled Starlings (Spodiopsar sericeus), Daurian Starlings (A. sturninus), White-shouldered Starlings (Sturnia sinensis) and Common
Starlings (Sturnus vulgaris). There is an observation record of birds
similar in plumage coloration to a hybrid of White-cheeked Starlings and Red-billed Starlings in Japan. A female White-cheeked
Starling and a male Red-billed Starling were observed to enter thesame nest hole and feed the nestlings in Sukumo City, Kochi Pref.
in 2009. The young which were assumed to be a hybrid of the twospecies fledged from this nest. Red-billed Starlings have been observed since 2007 in this city, which suggests that there was a goodchance that both the species would interbreed because they share acommon habitat and ecology. I would like to pay attention to breeding between the species of Sturnidae including Red-billed and White-cheeked Starlings in other areas in the future.

Literature
Enomoto Y. 1941. Wild Bird Handbook (Vol. 2). Osaka Chapter, Wild Bird Societyof Japan, Osaka. [J]Koshikawa S. 2006. Why has the number of communal roosts of the White-cheeked
Starling around the station increased? - easy driving away would increase thenumber of roosts around the station and man-made structures- .Urban Birds 23: 2740. [J]Saito T. 1986. Polygamy in a season in the White-cheeked Starling. The Breeding
Strategies of Birds (Vol. 1). (Yamagishi S. ed.) Pp107-129. Tokai University Pub.,
Tokyo. [J]Sato S., Kimura H., Hirata S. & Okai Y. 2010. A case of inter-specific breeding by
the pair of White-cheeked Starling and Red-billed Starling. Japn. J. Ornithol. 59:76-79. [J+E]
Yamaguchi Y. & Saitou T. 1997. Intraspecific nest parasitism in the grey starling(Sturnus cineraceus). Ecological Research 12:211-221.
Yamaguchi Y. 1997. Intraspecific nest parasitism and anti-parasite behavior in theGrey starling, Sturnus cineraceus. Journal of Ethology 15:61-68.
Yamaguchi Y. 2000. Parasitism strategy of the grey starling, Sturnus cineraceus :Selection based on host characters and nest location. Ecological Research 15:113120.

AuthorYasuhiro YAMAGUCHI

Agricultural Research Center,Wildlife Management Laboratory

I studied White-cheeked Starlings in graduate school. It was hard on me to carryout a research in the field from morning
till evening every day in the breeding
season. But looking back now, I reallyfeel that I was very happy in those days
when I could be deeply absorbed in thestudy. Nowadays, I wish to keep studying
with an inquiring mind.
yamay@affrc.go.jp

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