Bird Research News

Vol.8 No.1

Crested Ibis

Toki (Jpn) Nipponia nippon

Morphology and classification
Classification: Pelecaniformes Threskiornithidae
Total length:
Wing span:
Wing length:
Tail length:
Culmen length:
Tarsus length:
Weight:♂ 772.1±33.4mm (N=8)♂ 1234.2±112.0mm (6)♂ 411.5±21.2mm (8)♂ 172.4±8.3mm (8)♂ 181.0±7.1mm (7)♂ 89.2±6.1mm (6)♂ 1775.9±120.1g (49)

♀ 731.0±27.2mm (10)♀ 1234.2±112.0mm (6)♀ 392.0±18.0mm (10)♀ 173.4±9.0mm (11)♀ 163.7±6.2mm (11)
♀ 86.3±4.9mm (6)♀ 1545.3±107.2g (30)All measurements after Sado Japanese Crested Ibis Conservation Center (2010).

Morphology:
Although Crested Ibises are not remarkable in sexual dimorphism,
males are somewhat larger than females. Sexual identification in
the field is possible when a breeding pair is together, but difficult
when the bird is alone. Crested Ibises have a decurved black billwith a red tip. Incidentally, the decurved bill is the shared featureof the ibis subfamily, Threskiornithinae. They have a bare facewith the vermilion skin exposed. A young bird has a paler face.
The feet are also vermilion, but paler than the head. Crested Ibises
can be easily distinguished from similar-sized Great Egrets by thefeatures when flying such as the extended neck, the legs shorter
than the tail, and the faster and more powerful wing beats.

Appearance:
The male and female are similar inplumage coloration. They look rosy
white all over in the non-breeding period
from September to January. The flightfeathers are reddish orange in the rachisand become paler towards the peripheryof the vane. The underpart of the wings
looks salmon pink in flight (or when thebirds fly overhead) (Photo 1). Crested
Ibises turns the plumage charcoal gray Photo 1. Crested Ibis inflight. The underpart
from the nape to the back in the breedingof the wings is brilperiod. However, they do not develop
liant salmon pink.
the breeding feathers by molting. They
rub the black lipid that comes off from the skin of the nape on thefeathers after they bathe (Photo 2). Since the lipid is not soluble inwater, it is thinly applied to the feathers after it is emulsified bywater (Uchida 1970). They look black immediately after bathing,but turn gray when they dry up. The gray of the feathers deepens
in color every time they bathe from January to April. When thebreeding period is over, however, Crested Ibises cease to rub thelipid on the feathers after bathing, and therefore the feathers become lighter in color until the back looks mottled in the molting
period when the old feathers arereplaced with new rosy white
ones. Crested Ibises become rosy
white all over again in September
when the molting period is over.
It is birds of over two years thatrub the lipid on the back feathersin the breeding season, and onePhoto 2. Male and female in theyear-old birds remain rosy white
breeding period.
in most of its plumage.

Vocalization:
Crested Ibises utter a loud voice that sounds like "Ta-a" or "Car",
which is suggestive of Large-billed Crows. They also make a quiet
sound like "Gwa, gwa" between male and female or when theyurge the other members of a flock to take off.

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2011.1.21. Last Revised:2014.2.13.

Distribution and Habitat
Distribution:
Crested Ibises are an endemic species of Northeast Asia. They
used to be widely distributed in Japan, Taiwan, China, the Korean
Peninsula and Primorskii (Ussuri area), Russia. Presently the only
wild population is breeding in China (primarily Yang County ofShanxi Province), but their reintroduction has been attempted inSado Island, Niigata Prefecture, Japan under a captive breeding
program.

Habitat:Crested Ibises prefer to use as a breeding ground a "Yato" landscape with a mixture of paddy fields and secondary woodlands.
They build a nest in a tall tree at the edge or in the interior ofwoodlands, and forage in a paddy field, on its levee and in a grassy
area around a paddy field. The birds that have moved to Honshu(the main island of Japan) from Sado Island where they were released forage in rice fields away from woodlands. It is said thatthey used to forage in a terraced paddy field of a hilly area and a
stream of a ravine as well in Sado Island. When Crested Ibises
were rediscovered in Yang County, China, they foraged in the rice
fields of a "Yato" landscape surrounded by hills. However, they
have started to breed in the lowland as the population increased,
and they occasionally nest in a tall tree in the residential areas.

Life history
1234 5 6 7breeding season

89 10 11 12
non-breeding season

Breeding system: Monogamy.
Life history:
Crested Ibises start to nest from March to April and lay eggs fromlate March to mid-May. They build a plate-shaped nest at the forkof a horizontal branch of trees, such as pine, oak and elm. The
male chiefly supplies exterior materials for the nest, while thefemale collects materials for the inner lining, such as dry grass andbranches with dead leaves. They continue to carry nest materials to
the nest to complete it while they incubate their eggs. The medianclutch size is three eggs (range 2-5 eggs). They lay an egg every
other day and start to incubate the first egg, which results in nonsimultaneous hatching. The male and female take turns incubating,but the female is mostly responsible for nighttime incubation incaptivity. It takes about 27 days for an egg to hatch. Both male andfemale are engaged in rearing the young. They feed half-digested
small animals to the chicks by regurgitating them. The nestlings
fledge about 40-45 days after hatching, but they are fed by theirparents for a while. The young grow up to be the same size as theadult bird in the autumn (five months after hatching) (Chikatsuji &Nagata 2009). In the breeding season, non-breeders roost in acommunal flock at night, but they forage alone or in a small flockof several birds during the daytime. The birds that failed in theirbreeding attempt also join the foraging flock. Crested Ibises usually form a large flock in the wintering period from November toFebruary, but some of them move around alone. In China, theycome down to the lowlands in a large flock and forage in dam sites
or riverside areas from late August to September. In the wintering
period, however, they move from the lowlands to the nesting
grounds in the hilly region (Ding 2004).

Daily behavior:
Reintroduced Crested Ibises feed in rice paddies and adjustment
wet rice fields of a countryside "Yato" landscape and roost in trees
adjacent to the feeding sites, such as Japanese ceder, Cryptomeria
japonica, and Quercus serrata. Crested Ibises leave their roost andBird Research News

Vol.8 No.1

2011.1.21. Last Revised:2014.2.13.

© Japan Bird Research Association
Sumiyoshi 1-29-9, Fuchu, Tokyo, Japan
start to feed in paddy fields at sunrise. They basically spend a dayalternating feeding with resting until they return to their roost site
before sunset. Unless disturbed, they usually spend a day foraging
for one or two hours and resting on a levee and a tree for one ortwo hours in spring and autumn. In summer and winter, however,they change their behavioral pattern drastically. During the coldest
period of winter (January and February), they spend the most partof a day foraging. In summer (July and August), on the other hand,
they spend the majority of a day resting on a tree (Nagata 2010).

Migration:
Crested Ibises used to be year-round residents in Sado Island, Japan and Shanxi province, China. Crested Ibises arrive in a large
flock in the Korean Peninsula in winter. It is also historically recorded that they arrived with cranes in winter at the major moat ofFukuoka Castle of Fukuoka Domain, northern Kyushu, southern
Japan. It is assumed, therefore, that the Russian population ofCrested Ibises was migratory and moved to the Korean Peninsula,Kyushu and Taiwan.

Diet and foraging behavior
When foraging, Crested Ibises use contactdependent method, in contrast to the egrets
that use the sight-dependent method. Crested
Ibises forage for their prey, inserting the billshallowly into the soil, and when they sense
their prey at the tip of a bill, they insert thebill deeply into the soil to pull out and gulp
it. The analysis of wild Crested Ibis feces
showed that their diet consisted of freshwater
crabs, frogs, insects of Coleoptera(Chrysolina aurichalcea) and insects of Diptera (Stratiomyidae soldier flies, horse flies, Photo 3. Crested Ibis
crane flies) before their extinction in the wild
carrying a loach(Sato 1983). The observation of released
and capturing anCrested Ibises revealed, on the other hand,earthworm.
that their diet included fish (Cobitidae loachand cyprinid fish), amphibians (Hyla japonica, Rhacophorus arboreus,
Rana rugosa, R. ornativentris, R. sususra, Lithobates catesbeianus andCynops pyrrhogaster), insects (adult and nymph of dragonflies, Coleoptera, Orthoptera and larvae of Diptera), crustaceans (freshwater crab
and Procambarus clarkii) and annelids (earthworm). Loach fish represents only 11-16% of their diet, but earthworms account for 36% insummer when paddy fields are not available to them as a feeding siteand 24% even in winter, which suggest that earthworms are their important food item (Nagata 2010).

Topics of ecology, behavior and conservation● History of extinction of wild Crested Ibises
The product records of feudal clans in the Edo period (17th to mid19th C) suggest that Crested Ibises were distributed in the area east of
Shimane Prefecture, western Japan on Japan Sea side and in the area
north of the Kanto region on the Pacific Ocean side in the 18th century. It is assumed, on the other hand, that they occurred throughout
Japan at the end of the Edo period (19th C) because they were recorded to be released in the feudal domains of western Japan. However,they were originally a breeder in eastern Japan and a winter visitor inwestern Japan. Approximately 100 Crested Ibises remained in Oki
Island, the Noto Peninsula and Sado Island in the 1940s, but they
sharply declined in the 1960s with only 10 birds or so remaining in theNoto Peninsula and Sado Island. Eventually only five birds survived inSado Island in 1979. The five birds were captured for their captive
breeding in 1981, when the wild population became extinct in Japan.
The extinction of Crested Ibises can be attributed to the hunting pressure in the Meiji era, the loss of the nesting grounds due to deforestation during World War II and land development and the use of pesti-

バードリサーチ生態図鑑
cides after the war.

● Reintroduction program of Crested Ibises
The Japanese population of Crested Ibises went extinct with the deathof the last female "Kin" in 2003. Since the descendants of two Crested
Ibises presented by China in 1998 and another three birds provided
afterwards have been breeding successfully in captivity, the Ministryof the Environment decided to reintroduce Crested Ibises to eastern
Kosado area of Sado Island in 2005. The genetic difference between
Japanese and Chinese Crested Ibises is only 11 bases (0.06 %) out of
16,793 base pairs of the whole mtDNA, which is a level within individual variation (Yamamoto 2009). Since the captive-raised Crested
Ibises of Japan exceeded 100 birds in 2008, 10 of them were releasedin Sado Island, followed by another 19 birds in 2009. Of the released
birds, only females dispersed from Sado Island to Honshu (the mainisland of Japan). The survival rates of the released Crested Ibises during the first six months were 80% for the first release and 78.9% forthe second one (Nagata 2010). As of the end of December 2013, a totalof 142 birds have been released in Sado Island. The Ministry of theEnvironment aims at establishing a population of 60 Crested Ibises inSado Island including eastern Kosado wildlife reserve by 2015.

● Present population of Crested Ibises
As of the end of December 2009, there are approximately 760 birds inYang and Ningshan Counties of Shanxi Province, China. In addition,
about 530 captive-reared birds are in six breeding facilities of China.
Also four Crested Ibises provided by China are kept in Changnyeong,South Korea. As of December 2013, there are a total of 187 birds in
the Sado Crested Ibis Conservation Center, the Reintroduction Station,and Observatory Facility of Sado City in Sado Island, Izumo and Nagaoka Captive Breeding Centers, Tama Zoo and Ishikawa Zoo in Japan. As of the end of December 2013, a total of 86 released and 12
newly born Crested Ibises are confirmed in the wild in Japan, with 96
birds in Sado Island and two in Honshu.

Literature
Chikatsuji H. & Nagata H. 2010. The Crested Ibis. Dictionary of Wild Animal Conservation. Asakura-shoten. [J]Ding C. 200４. Research on the Crested Ibis. Technology and Education Press ofShanghai, Shanghai. [C]Nagata H. 2010. Dispersal and foraging behaviors of re-introduced Crested Ibis
Nipponia nippon in Sado Island. Kankyo-kenkyu, 158:69-74. [J+E]
Sato H. 1968. A note on the plumage color of Japanese Crested Ibis. Tori 18:301-313.
[J+E]
Sato H. 1983. Memories of wild Crested Ibis. "Toki" Nipponia nippon: Poetry offlight that disappeared in the dusk. (Yamashina Y. and Nakanishi G. chief eds).
Pp.78-89. Kyoikusha. Tokyo. [J]
Sado Japanese Crested Ibis Conservation Center. 2010. Handbook of method andfacility for breeding Crested Ibis (the first edition). Ministry of the Environment,&Niigata Prefecture. Sado City. [J]Uchida Y. 1970. On the color change in Japanese Crested Ibis: A new type of cosmetic coloration in birds. Misc. Rep. Yamashina Inst. Ornithol. 6:54-72. [J+E]
Yamamoto Y. 2009. The genetic diversity in the Crested Ibis In: Japan-China International workshop report of Crested Ibis Reintroduction Project. Pp.22-25. Birdlife
Asia. Tokyo. [J]Authorfor Toki and Ecological Restoration,
Hisashi Nagata Center
Niigata University
Three and a half years have passed since I was involved in Crested Ibises
and it is almost two years since I moved to Niigata. The latitude of myhouse increases every time I move. The next time,
where ? Since I was born and raised in southern Japan, itis hard to get acclimated to the snow. But in Kagoshima I
encountered the heavy snow I had not experienced inNiigata on this New Year's Eve when I was back home. I
hope that this year Crested Ibises will hatch their young
in the wild. hnagata@gs.niigata-u.ac.jp

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