Bird Research News

Vol.1 No.3

Eastern Curlew

2004. 11.08.

Horoku-Shigi (Jpn) Numenius madagascariensis
Migration:

Morphology and classification

Eastern Curlews areassumed to be monogamous. It seems that themale and female incubate and take care of thechicks.

Classification: Charadriiformes Scolopacidae
Total length: 615mm (535-680)
Wing length: 326.7mm (312-340)
Tail length:119.2mm (115-126)
Culmen length: 180.5mm (138-206)
Tarsus length: 90mm (81-96)
Weight:1047g (740-1301)
Total and tarsus lengths after Enomoto 1941, and other parts were measured fromindividuals captured for satellite-tracking study in Brisbane, Australia in 1997-1999.

Photo 2. Chicks of Eastern Curlews havestraight bills in contrast with the adluts

Appearance:
Pale brown overall with vertical dark brown stripes. Brownish hue
isthan the Eurasian Curlew.
２.stronger
分布と生息環境

Vocalization:● Non-stop flight across the sea

Call sounds like "Carlew, Carlew".

Distribution and Habitat
Distribution:
Eastern Curlews breed in the wetlands from the middle reaches of
the Amur to Kamchatka and winter in mudflats from Southeast
Asia to Australia. However, some of them winter in Japan.

Habitat:
Although the breeding ground of Eastern Curlews lie in bogs ofsphagnum moss, they actually build nests in more arid patchessuch as sedge grassland adjacent to those bogs, where they use forforaging. It is assumed, therefore, that they occur densely in sites
with both habitats for nesting and feeding (Ueta & Antonov 2000).
Outside of the breeding season, the species uses mudflats where it
forages for crabs with its long bills.

Life history
12

3

4

5wintering

67

Topics of ecology, behavior and conservation89

breeding migration

101112

wintering

Eastern Curlews migrating between Russia and Australia weresatellite-tracked as a jointgovernment study of Japan andAustralia from 1998 to 2000. The
study showed that Eastern Curlews
flew non-stop from Australia toTaiwan, the east coast of China andJapan in spring and that they flew
non-stop from the east coast ofChina to Indonesia in autumn(Figs.1 and 2, Driscoll & Ueta
2002). Although it would be safer
to fly along island chains, strong
fliers, such as curlews might give
Photo 3. An Eastern Curlewefficiency priority over safety.
with a satellite transmitter
Figure 2 shows the date and time
mounted on the back.
and the flight distance for one of
the individuals that we tracked.
The bird flew at a speed of about 50 km/h based on the result of
the satellite tracking. Therefore, it flew non-stop more than 5000
km at least for 4 days from March. 5 to 9, though it is possible thatit took a rest on New Guinea.

Breeding system:
Eastern Curlews are assumed to be monogamous.
It seems that the male andfemale incubate and takecare of the chicks.

20kmApr 28Jun 24

Mar 7
15:35
2045 km

Apr 5
Photo 1. Nest at a dry site in the wetland

Clutch size and egg size and color :Clutch size is four eggs. The eggs have reddish brown flecks on anocher ground.

Incubation, chick-rearing periods and fledging rate: :Incubation period is about four weeks. Chicks leave the nest when
their down dries up after hatching and begin to forage for smallorganisms, such as insects in the wetlands along with their parentbirds. It takes more than four weeks for the chicks to start flying.

5♪ http://www.bird-research.jp/1_shiryo/koe/horoku_090409_sanbanse_moriya.mp3
Toshifumi Moriya

30Jun 17

Nest:
Eastern Curlews build
nests on raised dry sites,such as hammocks in thewetlands using dead grasscollected from the surroundings.

Mar 9 20:57

May 3

Sep 7

Mar 5
16:03

Sep 12
Sep 24
Mar 24

Fig. 1. Migration routes ofEastern Curlews inspring (○) and autumn(●).

Fig. 2. Transoceanic route of an Eastern
Curlew migrating from Australia via
Daito Island, Japan to its breeding
grounds of Russia.

Bird Research News

Vol.1 No.3

2004. 11.08.

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

バードリサーチ生態図鑑● Behavior of turning back along the way● Navigation during the migration

As many as half the Eastern Curlews (18 of 37 birds) that wetracked aborted the spring migration on the way and returned tothe wintering grounds (Figure 3). Although the possibility remainsthat the transmitter mounted on their back was a burden, Finn etal. (2001) and Driscol (pers. comm.) argue that Eastern Curlews
tend to turn up again a little after they have set out on their spring
migration in Australia. In addition, they report that 25-30% of thewintering population spends the summer in Australia. Some ofother Scolopacidae also stay in Australia during the summer, instead of returning to the breeding grounds, but they account forless than 10% of the wintering population. It is assumed, therefore,that the behavior of turning back along the way is characteristic ofEastern Curlews.
In order to explain the reason why Eastern Curlews frequently
discontinued the migration, I examined in the computer simulation
the conditions under which the behavior was adaptive (Fig 4; Ueta2000). The result showed that the abandonment of migration wasadaptive when the annual mortality rate was 30%, but it was not
adaptive at all when the rates were 50% and 80%. It is suggested
that the abandonment of migration is adaptive for large species,
such as Eastern Curlews whose annual mortality rate is low andmigration involves many risks, but it is not adaptive for small
migratory birds with a high annual mortality rate

4/9

3/21

Eastern Curlews can rely on no landmarks, such as shorelines
when crossing over the sea. The satellite tracking showed that theyflew in a straight line across the ocean. And on the way, they seem
able to make correction for wind drift. The tracked birds were hit
by a typhoon on migration and some of them were swept eastwards from the normal route in 1997. These birds returned to thewintering grounds. This incident suggests that they can not only
keep their flight direction constant but also orientate themselves
and return to the wintering site, even if blown off course. When weobserve vagrant birds that arrive in Japan, we wonder if they willbe able to return to their breeding grounds, but there may be nothing to worry about. They probably orient themselves as Eastern
Curlews did.

Literature
Enomoto Y. 1941. The body size of Japanese birds. Japan Wild Bird Society
Osaka Branch, Osaka. [J]Driscoll P. & Ueta M. 2002. The migration route and behaviour of Eastern Curlews Numenius madagascariensis. Ibis 144: E119-E130.
Finn PG, Catterall CP & Driscoll PV 2001. The low tide distribution of Eastern
Curlew on feeding grounds in Moreton Bay, Queensland. Stilt 38: 9-17.
Kurechimaru A.V. 1996. Field guide to birds of Northern Siberia. Bun-ichi Sogo
Shuppan, Tokyo. [J]Ueta M. 2000. Is migration abortion by Eastern Curlews adaptive? OrnithologicalSociety of Japan 2000 Annual Meeting Abstracts. [J]Ueta M. & Antonov A. 2000. Habitat preference of Eastern Curlews at breeding
Site. Emu 100: 72-74.
Ueta M., Antonov A., Artukhin Y. & Parilov, A. 2002. Migration routes of Eastern Curlews tracked from far east Russia. Emu 102: 345-348.
Languages of literature cited other than English: [J] in Japanese,

5/1

4/7

3/24
5/3
5/7

3/22Mutsuyuki UETA Japan Bird Research Association

Fig. 3. Two cases of Eastern Curlews which stopped their migration on theway and returned to the wintering grounds of Australia.

Difference in lifetime breeding success rate
between the curlews which stopped theirmigration and ones which continued it

Annual mortality 30 %AuthorAnnual mortality 50 %Annual mortality 80 %Frequency of physicalexhaustion 5 %10-1-22
10-1-22
10-1-2

I have been to Russia and Australia on the joint research of EasternCurlews, working together in the multi-national party. As a poor
speaker of English, I was more comfortable in Russia because I was
not under the stress of communicating in English. However, the research locations in Russia was extensive wetlands that is extremely
hard to move about, compared to sandy beaches in Australia where it
was easy to walk. I was out of luck in the first year of the study, because I thought it was easier to buy a pair of long boots in Russia forthe study. The new boots gave me a lot of shoe sores.
mj-ueta@bird-research.jp

Frequency of physicalexhaustion 10 %Frequency of physicalexhaustion 20 %

5102051020510

Increase of mortality due to continuing the migration when
physical strength is exhausted

20P < 0.05Fig. 4. Differences in the fitness between Eastern Curlews which stopped
their migration and ones which continued it based on a computer simulation. ■: On the assumption that annual mortality is decreased due tothe abandonment of migration, □: On the assumption that annual mortality does not change.

http://www.youtube.com/watch?feature=player_embedded&v=lyuSGexsEmo
Toshifumi Moriya

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