Bird Research News

Vol.7 No.1

2010.1.18.

White-naped Crane

Manazuru (Jpn) Grus vipio

Morphology and classification
Classification: Gruiformes Gruidae
Total length:
Tail:
Tarsus length:

125cm
164-230mm
230-305mm

Wingspan:
530-610mm
Culmen length: 115-160mm
Weight:5.1-6.0kg

Total length is after del Hoyo (1996), and others after Kiyosu (1978).

Appearance:
The plumage of White-naped Cranes is the same in males andfemales, with the upperpart and wings pale gray and underpart
dark gray. The nape is strikingly white, hence the English name.
There are red patches of exposed skin around the eyes. Whitenaped Cranes look pretty
from a distance, but thisdenuded part is reminiscentof a ruddy-faced middleaged man at close range.
Juveniles are roughly similar
to adults in plumage, exceptthat the juveniles are paler inthe exposed area around theeye and tinged with drab
brown especially on the Photo 1. White-naped Cranes.
head.

Call:
They utter a voice that sounds like “Krull” or “Gyurr”.

Distribution and Habitat
Distribution:
The main breeding grounds of White-naped Cranes are wetlands inRussia, the southeastern part of Northeast China and northeastern
Mongolia. As a winter resident, White-naped Cranes come over tothe reclaimed land and paddy fields of southern Japan, especiallyKyushu. It is estimated that the 2000 to 3000 cranes wintering in
the Izumi Plain, Kagoshima Pref. represent half of the world population of this species. Lake Poyang located in the middle reachesof the Yangtze River in China is another major wintering site,which compares with Izumi. There are some other minor winteringsites in southeast China and the Korean Peninsula.

Habitat:In contrast with Hooded Cranes which share wintering groundswith White-naped Cranes, White-napes breed in extensive wetlands. They primarily winter in rice fields, but use rivers and lakes
as a wintering site as well. They usually roost in sandbars, mudflats, shallow ponds and marshes. In Izumi, however, they use
paddy fields filled with water as a roost site.

Life history
Breeding system:
White-naped Cranes are monogamous and it is assumed that they
do not usually change their partners once they are paired. If theylose their partners, however, they pair anew.

Nest:Nest of stacked grasses is built at a raised spot with little or no riskof submergence in a marsh.

1 2 3 4 5
wintering migration

67 8breeding

910 11 12migration4♪ http://www.bird-research.jp/1_shiryo/koe/manazuru1_071129_izumi_kaji.mp3
Kyoko Kajimoto

Eggs:
Clutch size of White-naped Cranes is 2 eggs. The egg size is 62 ~62.8mm for the major axis and about 102 ~ 103mm for the minoraxis. The egg has gray and dark brown flecks on the ground oflight brown tinged with dark gray.

Incubation and nestling periods:
The incubation period of White-naped Cranes is 28 to 32 days.
Hatchlings are densely covered with natal down. The upperparts
are pale brown with a back washed over by a rust and the underparts are cream. Juveniles can live on their own 70-75 days after
hatching, but they spend the wintering period with their parents.
The young become independent during the spring migration orafter the arrival at their breeding grounds. Independent young birds
usually stay in the flocks of non-breeding birds for 2-3 years until
they begin to breed.

Migration:
Satellite-trackings revealed the migration routes of White-naped
Cranes in the early 1990s. The cranes wintering in the Izumi Plain
depart for the breeding grounds between mid-February and early
March to reach the Korean Peninsula through western Kyushu, andIki and Tsushima Islands. They stay for a long period of time inChorwan and Panmunjom on the border between North and SouthKoreas. After they have fed sufficiently there, they head north forthe breeding grounds, such as the Sanjiang Plain of northeastern
China and the wetlands of southeastern Russia through Kumya andLake Khanka (Figure 1). They use the same routes in the autumn
southward migration. The cranes breeding west of these areas, on
the other hand, do not move to the Korean Peninsula and Japan towinter. Instead, theyhead south for thewintering grounds
ムラビヨフカ ヒンガンスキーof southeastern Chi三江平原
ダウルスキーna, such as Lake
ザーロン
Poyang in the midハンカ湖
dle reaches of the
金野YangtzeRiver
白城through Baicheg and鉄原
the estuary of the渤海
Yellow River on the板門店
黄河河口
coast of the Bohai
鹿児島県出水Sea, which they useas a long time stopoポーヤン湖
ver site (Fig. 1).
These stopover sites Fig. 1. Examples of autumn and spring migration routes of White-naped Cranes revealed
are also used byby satellite tracking. Red lines show spring,
many other waterand blue autumn migration routes, respecbirds while on mitively. Drawn after Higuchi et al. (1994,gration.
1996).

Diet and behavior:
The staple diet of White-naped Cranes consists of grass roots,
seeds and small animals. White-naped Cranes dig the soil more
frequently to feed than Hooded Cranes which share the wintering
grounds with White-napes. Therefore, the fields White-naped
Cranes use frequently as a foraging site look as if they had been
plowed.

Topics of ecology, behavior and conservation● Project for decentralizing the wintering grounds of Whitenaped Cranes ?
Due to the conservation efforts in the Izumi Plain, White-naped
Cranes that had been reduced to dozens of birds in the late 1940s(shortly after the Second World War) increased to 2,000 - 3,000
birds in the 2000s (Fig. 2). This is one of the successful conserva-

Bird Research News

Vol.7 No.1

2010.1.18.

バードリサーチ生態図鑑

12000
10000

Hooded CraneWhite‐naped Crane

8000
6000
4000
2000
0

1947
1951
1955
1959
1963
1967
1971
1975
1979
1983
1987
1991
1995
1999
2003
2007

Number of wintering cranes© Japan Bird Research Association
Sumiyoshi 1-29-9, Fuchu, Tokyo, JapanFig. 2. Changes in the population of White-naped and Hooded Cranes inthe Izumi Plain, Kagoshima Pref. Drawn after the information of Izumi
Crane Museum. (http://www.city.izumi.kagoshima.jp/izumi_crane/default.asp).

tion cases that Japan can be proud of in the world. As a result,however, all the wintering individuals of this species in Japan havebeen concentrated in Izumi, which might present a serious threat tothe species survival, in the case of outbreaks of infectious diseases.
Therefore, the project for decentralizing the wintering grounds isunderway to avoid this risk. In Nagahama reclaimed land, ImariCity, Saga Prefecture, for example, the Imari Crane Society andthe Wild Bird Society of Japan have played a central role in managing a wintering habitat to create a new wintering ground forWhite-naped Cranes since 2003. They have begun to use the reclaimed land as a stopover site in the spring and autumn migrations, but only one family spend the winter there each year. Theproject is far from satisfactory. The same problem is observed for
the Hooded Cranes inYashiro, Yamaguchi
Prefecture. Apparently, the family thatoccupied the wintering site claims anextensive
territory
and tend to expel
other cranes.
Forfurther information,please see the following
site.
http://www.wbsj.org/
Photo 2. Decoy of White-naped Cranes atnature/kisyou/crane/
Nagahama reclaimed land, Imari, Saga.
index.html● What decides the migration route?
For any migratory birds, migration is the biggest event of the year
and an ordeal full of dangers. As the distance of travel becomesshorter, the burden seems to be relieved. The simplest answer
would be a straight flyway between the breeding and wintering
grounds. However, the real migration routes cannot be determinedso simply. Since land birds cannot take wing once they get waterlogged, they try to avoid flying over an extensive body of water,such as the sea. Therefore, White-naped Cranes wintering in Izumi
fly across the Sea of Japan through Iki and Tsushima Islands andhead north for the breeding grounds along the Korean Peninsula.
Then how do White-naped Cranes determine the migration routes
over the continent ? Comparison between the migration routes
revealed by satellite tracking and the land use along the routes
showed that the cranes took the routes that passed through wetlands and were the shortest possible to the breeding or wintering
grounds (Fujita et al. 2004). The sea is a dangerous place for
White-naped Cranes to cross, but other habitats than wetlands alsopresent a danger to them when they land. It is assumed, therefore,that the cranes try to fly over wetlands in precaution against anemergency landing due to bad weather.

● White-naped Cranes arrive late in the wintering grounds
and depart early for the breeding grounds
As autumn deepens into winter, Hooded Cranes arrive one after
another in the Izumi Plain and almost all wintering individuals
assemble there in November. White-naped Cranes, on the otherhand, do not come flying as readily as Hooded Cranes. The number of White-naped Crane arrivals reaches its peak after the cold
wave in late December or early January. And most of the wintering White-napes depart for the breeding grounds in February,
while Hooded Cranes, in contrast, stay in Izumi until March.
Since White-naped Cranes breed in more southern regions than
Hooded Cranes, it is assumed that White-napes arrive later in thewintering grounds. However, Hooded Cranes could also spend thefirst part of winter in some stopover sites in the Korean Peninsula
before arriving at Izumi. Therefore, there must be some otherreasons for the later arrival of white-napes. Possible reasons include a tendency of White-naped Cranes to winter in more northern areas or to hold a family territory and a tendency of Hooded
Cranes to be attracted more easily to the feeding. I would like toknow the real reason.

Literaturedel Hoyo J., Elliott A. & Sargatal J. eds. 1996. Handbook of the birds of the world.
Vol.3. Hoatzin to Auks.Lynx Edicions, Barcelona.
Fujita G., Guan H.L., Ueta M., Goroshko O., Krever V., Ozaki K., Mita N. &Higuchi H. 2004. Comparing areas of suitable habitats along travelled andpossible shortest routes in migration of White-naped Cranes Grus vipio in East
Asia. Ibis 146: 461-474.
Higuchi H., Ozaki K., Fujita G., Minton J., Ueta M., Soma M. & Mita N. 1996.
Satellite-tracking of White-naped Crane Grus vipio migration, and the importance of the Korean DMZ. Conserv. Biol. 10: 806-812.
Higuchi H., Ozaki K., Fujita G., Soma M., Kanmuri N. & Ueta M. 1992. Satellite
tracking of the migration routes of cranes from southern Japan. Strix 11: 1-20.
Higuchi H., Ozaki K., Golovuskin K., Goroshko O., Krever V., Minton J., Ueta M.,
Andronov V., Smirensky S., Ilyashenko V., Kanmuri N. & Archibald G. 1994.
The migration routes and important rest-sites of cranes satellite tracked fromsouth-central Russia. In: Higuchi H. & Minton J. (eds). The Future of Cranes
and Wetlands. Pp. 15-25. Wild Bird Society of Japan, Tokyo.
Kiyosu Y. 1978. Enlarged and revised edition Encyclopedia of Japanese birds.
Kodansha, Tokyo. In Japanese.

AuthorMutsuyuki UETA Japan Bird Research Association
I was employed by the Wild Bird Society of Japan for the satellite
tracking of White-naped Cranes in 1992 when I was fresh out of college. With Drs. Higuchi and Fujita that are now on the staff of theUniversity of Tokyo and Dr. Ozaki at Yamashina Institute, I attachedtransmitters to the cranes in Izumi, their major wintering ground, tosatellite-track them while on migration. We were given a hard time by
the media calling the study as abuse of cranes, but the study broughtsome conservation results, such as the establishment of their North
Korea stop-over site as a nature reserve and the conservation advancement of their breeding grounds of China, based on the findings of thestudy. I realized effects ofscientific studies on conservation. I owe White-naped
Cranes what I am now as anornithologist .
mj-ueta@bird-research.jp

Commemorative photo of 1995 withthe crane research team in Russia

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