Justification This species has a small population which is thought to be declining rapidly as a result of disturbance at breeding sites, predation and mortality from drift-net fisheries. It is therefore listed as Vulnerable.

Family/Sub-family Alcidae

Species name author (Temminck, 1835)

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

Identification 26 cm. Small alcid. Short, thick, pale bluish-grey bill. Black head with black crest (summer only) and white stripes on sides of head from top of eyes, meeting on nape. Blackish and bluish-grey upperparts. White throat and underparts. Greyish-black flanks. Yellowish-grey legs and feet. Juvenile has browner upperparts. Similar spp. Ancient Murrelet S. antiquus lacks crest and has black on throat.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

2,500-9,999

decreasing

1,080,000 km²

No

Range & population Synthliboramphus wumizusume is endemic to the warm current regions near central and southern Japan, where it breeds on uninhabited islands. The most important breeding sites are in Kyushu, notably the islands of Biro-jima, Koya-jima and Eboshi-jima, and the Izu Islands, notably Onbase-jima and Onohara-jima. Breeding has also been recorded on Gugul Island off the southern coast of South Korea, and it may also breed in Peter the Great Bay, Primorye, Russia. After breeding, birds move northwards to an area south-east of Hokkaido. They also winter along the coasts of Honshu and Kyushu, some birds apparently moving south to the Nansei Shoto Islands. The population is unlikely to exceed 10,000 birds. It is still declining in many localities, particularly the Izu Islands¹.

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

Ecology: It frequents rocky islets and headlands during the breeding season (mid-February-early May), nesting in single pairs, small groups and sometimes in large colonies. In the non-breeding season it occurs offshore, occasionally entering bays.

Threats Sport fishing on isolated offshore reefs and islets is a major threat as it causes direct disturbance and habitat degradation. Fish, discarded by anglers, attract crows and gulls which then predate eggs and chicks. Indeed, predation by crows is the main threat on Biro-jima and Onohara-jima. Black rat Rattus rattus has been introduced to some nesting colonies and has almost extirpated the population on Koya-jima. Annual mortality of adults in drift-nets has been estimated at 1-10% of the total breeding population, but these figures may be underestimates. There is some evidence that fish stocks have declined around the Izu Islands because of changes in water temperature. Oil spills are a potential threat.

Conservation measures underway CMS Appendix I. It is legally protected in Japan. Several breeding colonies are protected as National Wildlife Protection Areas, including Nanatsu-jima, Kiinagashima, Okino-jima and Danjo-gunto. Gugul Islet (South Korea) has been designated as a Natural Monument. In Japan, educational materials have been produced to inform fishers about the species and the importance of the largest known breeding colony on Biro-jima Island.

Conservation measures proposed Conduct co-ordinated surveys of breeding sites to determine current population size and trends. Establish new protected areas at important colonies that are not officially protected. Restrict human access to islands with breeding colonies. Control predators at breeding colonies. Research and design methods to reduce the bycatch of seabirds by fisheries.

References BirdLife International (2001). 1. Carter et al. (2002).

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), Simba Chan (Wild Bird Society of Japan), Mike Crosby (BirdLife International), James Gilroy (BirdLife International), Nic Peet (BirdLife International)

Contributors Koji Ono (Kushiro Nature Conservation Office)

IUCN Red List evaluators Jeremy Bird (BirdLife International), Stuart Butchart (BirdLife International), James Gilroy (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Synthliboramphus wumizusume. 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.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

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