Justification 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.

Family/Sub-family Corvidae

Species name author Bonaparte, 1851

Taxonomic source(s) Sibley and Monroe (1990, 1993)

Identification 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.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

5,800

decreasing

820 km²

Yes

Range & population Garrulus lidthi is endemic to the islands of Amami-ooshima and Kakeroma-jima, part of the Nansei Shoto Islands, Japan. It was previously common in the central mountains of Toku-no-shima but is now extinct there. Its population was estimated at c.5,800 birds in the 1970s, but it declined through to the 1990s. Owing to alien predator control and natural forest regeneration it may have begun to increase since 2000¹.

Important Bird Areas Click here to view map showing IBAs where species is recorded and triggers any of the IBA criteria.

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 fields¹. Sweet potato, insects, seeds fruits, reptiles, including Okinawa pit-viper Trimeresurus flavoviridis, and maybe 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 A high proportion of nests are predated by crows and mammals and the small Indian mongoose Herpestes javanicus has been reported to prey on young birds. 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 measures 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 increasing.

Conservation measures proposed Conserve and restore remaining areas of mature forest on Amami-ooshima. Provide nest-boxes in areas where there is a shortage of natural nest-holes. Control alien predators on Amami-ooshima. Survey the central mountains of Tokunoshima, where it was reported in the 1920s. Investigate the potential for reintroduction on Tokunoshima.

References BirdLife International (2001). 1. Yukihiro Kominami in litt. (2007).

Further web sources of information

Fully detailed species accounts from the Threatened birds of Asia: the BirdLife International Red Data Book (BirdLife International 2001), together with new information collated since the publication of the Red Data Book

Text account compilers Phil Benstead (BirdLife International), Jeremy Bird (BirdLife International), Mike Crosby (BirdLife International), Nic Peet (BirdLife International)

Contributors Yukihiro Kominami (Wild Bird Society of Japan)

IUCN Red List evaluators Jeremy Bird (BirdLife International), Stuart Butchart (BirdLife International), Mike Crosby (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Garrulus lidthi. Downloaded from http://www.birdlife.org on 10/2/2010

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.

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