This jay has a small population which is suspected to have declined, possibly as a result of increased levels of predation. It therefore qualifies as Vulnerable. If surveys reveal that the population is now increasing following predator control and forest regeneration, the species may warrant downlisting.
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.
Distribution and populationGarrulus lidthi
38 cm. Large, brown and blue jay. Dark blue head with blue-black forehead and lores. Dark blue tail. Rich chestnut back and underparts. White tips to flight and tail feathers. White flecking on throat. Bicoloured bill with horn tip and grey-blue base. Voice Unknown.
endemic to the islands of Amami-ooshima, Kakeroma-jima, Uke-jima, Edateku-jima, part of the Nansei Shoto Islands, Japan
(BirdLife International 2001, K. Ishida in litt
. 2012). Its population was estimated at c.5,800 birds in the 1970s, but it may have declined through to the 1990s. It is precautionarily treated as undergoing a continuing decline overall, although it may have begun to increase since 2000, owing to alien predator control and natural forest regeneration (Yukihiro Kominami in litt
. 2007), and may now be stable (K. Ishida in litt
. 2012). Some observations indicate a population increase in the northern Kasari peninsula of Amami-ooshima (M. Takashi per
K. Ishida in litt
. 2012).Population justification
The global population is estimated to number c.5,800 individuals (Nishidi 1974 in Brazil 1991), equivalent to c.3,900 mature individuals. It has been suggested that the population now exceeds 5,800 individuals (K. Ishida in litt
. 2012); however, further research is required. The population is presently assumed to form one sub-population, but future genetic research (K. Ishida in litt
. 2012) is expected to confirm whether this is the case.Trend justification
It has been suggested that the population is now stable (K. Ishida in litt
. 2012), but until new data are available the trend is precautionarily assumed to be negative. Although forest loss is unlikely to be having a significant impact upon this species, reduced reproductive success owing to nest predation by mammals is perhaps still leading to a moderate decline overall.Ecology
It occurs from sea-level into the hills, in subtropical evergreen broadleaved forest, coniferous forest, and in woodland around cultivation and human habitation, showing a significant preference for mature forest. It feeds on and caches the acorns of Castanopsis cuspidate
, Quercus glauca
and other oaks when they are available; if this food supply is exhausted birds will feed in agricultural fields (Yukihiro Kominami in litt
. 2007). Sweet potato, insects, spiders, seeds, fruits, reptiles, including Okinawa pit-viper Trimeresurus flavoviridis
, and birds are also included in its diet. It forages in trees and on the ground. Breeding takes place from late January or early February until May. Threats
In some years, a high proportion of nests are predated by crows and mammals, and the small Asian mongoose Herpestes auropunctatus
and snakes have been reported to prey on young birds and eggs. However, it is not known whether this apparently increased predation pressure will have a long-term effect on the population. The numbers of Large-billed Crow Corvus macrorhynchos
on Amami-ooshima have recently increased, probably because of increased garbage disposal on the island. The effect of logging on its population is probably relatively small. Conservation Actions Underway
It is legally protected in Japan. Yuwandake on Amami-ooshima was established as a National Wildlife Protection Area, mainly for the conservation of this species and Amami Thrush Zoothera major
. Several surveys and ecological studies have been completed. Introduced small Indian mongoose has been controlled within its range in recent years and as a result the species may now be stable or increasing. The increase in numbers of Large-billed Crows Corvus macrorhynchos
on Amami-ooshima has been halted by improvements in refuse management (K. Ishida in litt
. 2012).Conservation Actions Proposed
Carry out surveys to obtain an up-to-date population estimate. Conduct regular surveys to ascertain whether the population is in fact stable or recovering. Conserve and restore remaining areas of mature forest on Amami-ooshima. Provide nest-boxes in areas where there is a shortage of suitable natural nesting sites. Control alien predators on Amami-ooshima.
BirdLife International. 2001. Threatened birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, U.K.
Brazil, M. 2009. Birds of East Asia: eastern China, Taiwan, Korea, Japan, eastern Russia. Christopher Helm, London.
Brazil, M. A. 1991. The birds of Japan. Chistopher Helm, London.
Further web sources of information
Detailed species accounts from the Threatened birds of Asia: the BirdLife International Red Data Book (BirdLife International 2001).
Text account compilers
Benstead, P., Bird, J., Crosby, M., Peet, N., Taylor, J.
Ishida, K., Kominami, Y.
IUCN Red List evaluators
Butchart, S., Symes, A.
BirdLife International (2014) Species factsheet: Garrulus lidthi. Downloaded from
http://www.birdlife.org on 16/03/2014.
Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 16/03/2014.
This information is based upon, and updates, the information published in BirdLife International (2000)
Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004)
Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.
To provide new information to update this factsheet or to correct any errors, please email BirdLife
To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.
Additional resources for this species