Gorsachius goisagi

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	AVES	CICONIIFORMES	ARDEIDAE

Scientific Name:

Gorsachius goisagi

Species Authority:

(Temminck, 1835)

Common Name/s:

English

–

Japanese Night-heron, Japanese Night Heron, Japanese Night-Heron

Assessment Information [top]

Red List Category & Criteria:

Endangered C2a(i) ver 3.1

Year Published:

2008

Assessor/s:

BirdLife International

Reviewer/s:

Butchart, S., Bird, J., Crosby, M.

Contributor/s:

Kominami, Y., He, F., Kawakami, K.

Justification:
This species has a very small, declining population, and therefore qualifies as Endangered. Declines are primarily a result of deforestation in its breeding and wintering ranges.

History:

2004	–	Endangered
2000	–	Endangered
1996	–	Vulnerable
1994	–	Vulnerable

Geographic Range [top]

Range Description:	Gorsachius goisagi breeds in Japan, and there has been one report of breeding from Taiwan (China). It has been recorded in spring and summer in Russia (Primorye and Sakhalin) and South Korea, and is a passage migrant in coastal mainland China and Hong Kong (China), and also in Taiwan. The main wintering area appears to be in the Philippines, but it has also been recorded as a non-breeding visitor to Indonesia, and as a vagrant to Brunei and Palau. It was apparently locally common in Japan until the 1970s, but by the 1980s and 1990s, had disappeared from many of its former breeding sites. There has apparently been just one recent record from mainland China, of two sightings at Wuyuan in Jiangxi Province in April 2006³. This relative paucity of recent records indicates that the population is now probably less than 1,000 mature individuals.
Countries:	Native: China; Hong Kong; Indonesia; Japan; Korea, Republic of; Philippines; Russian Federation; Taiwan, Province of China Vagrant: Brunei Darussalam; Palau
Range Map:	Click here to open the map viewer and explore range.

Population [top]

Population:	Recent work in Japan suggests the previous assertion that the global population comprises fewer than 1,000 individuals may have been overly pessimistic. Hence, the true figure probably lies within the band 1,000-2,500 individuals.
Population Trend:	Decreasing

Habitat and Ecology [top]

Habitat and Ecology:	It breeds in heavily forested areas, including coniferous, broadleaved and degraded forest, on hills and on the lower slopes of mountains (up to 1,500 m), where there are watercourses and damp areas. It winters in dark, deeply shaded forest near water up to 2,400 m. It forages mainly in forest, but will use swamps, rice-fields and farmland and is mainly crepuscular. Breeding has been recorded from April to July¹. Earthworms are probably the principal food source, but land snails, crabs, ground and scarabid beetles are all present in its diet^2,4.
Systems:	Terrestrial; Freshwater

Habitat and Ecology:

It breeds in heavily forested areas, including coniferous, broadleaved and degraded forest, on hills and on the lower slopes of mountains (up to 1,500 m), where there are watercourses and damp areas. It winters in dark, deeply shaded forest near water up to 2,400 m. It forages mainly in forest, but will use swamps, rice-fields and farmland and is mainly crepuscular. Breeding has been recorded from April to July¹. Earthworms are probably the principal food source, but land snails, crabs, ground and scarabid beetles are all present in its diet^2,4.

Systems:

Terrestrial; Freshwater

Threats [top]

Major Threat(s):	The main threat is deforestation in both its breeding and non-breeding ranges. The development of dense scrub undergrowth in forest and on abandoned farmland (following a change in traditional agricultural practices) is believed to reduce the suitability of these habitats for feeding. It has probably been hunted in many parts of its range. It declined rapidly on Miyake-jima in the Izu Islands, where it was formerly abundant, following the introduction of Siberian weasel Mustela sibirica in the early 1970s. Today nest predation by Corvids is an increasing threat as crow populations increase in urban and suburban areas.

Major Threat(s):

The main threat is deforestation in both its breeding and non-breeding ranges. The development of dense scrub undergrowth in forest and on abandoned farmland (following a change in traditional agricultural practices) is believed to reduce the suitability of these habitats for feeding. It has probably been hunted in many parts of its range. It declined rapidly on Miyake-jima in the Izu Islands, where it was formerly abundant, following the introduction of Siberian weasel Mustela sibirica in the early 1970s. Today nest predation by Corvids is an increasing threat as crow populations increase in urban and suburban areas.

Conservation Actions [top]

Conservation Actions:	Conservation Actions Underway It is legally protected in Japan and Hong Kong. Birds may occur in protected areas in Japan and it has been recorded in Quezon National Park, Philippines. Environmental Impact Assessments are conducted prior to major developments in Japan, and if this species is identified using a site mitigation measures are taken⁴ Conservation Actions Proposed Survey its breeding range in Japan and its wintering range in the Philippines. Establish a monitoring programme of its breeding and wintering populations. Study its home-range requirements using radio-telemetry. Protect and manage forests in its breeding and wintering grounds. Ensure official protection throughout its range and strengthen and enforce legislation to prevent the sale of this (and other threatened) species. Establish public-awareness programmes concerned with its conservation. Control and monitor invasive species where appropriate within its range.

Conservation Actions:

Conservation Actions Underway
It is legally protected in Japan and Hong Kong. Birds may occur in protected areas in Japan and it has been recorded in Quezon National Park, Philippines. Environmental Impact Assessments are conducted prior to major developments in Japan, and if this species is identified using a site mitigation measures are taken⁴

Conservation Actions Proposed
Survey its breeding range in Japan and its wintering range in the Philippines. Establish a monitoring programme of its breeding and wintering populations. Study its home-range requirements using radio-telemetry. Protect and manage forests in its breeding and wintering grounds. Ensure official protection throughout its range and strengthen and enforce legislation to prevent the sale of this (and other threatened) species. Establish public-awareness programmes concerned with its conservation. Control and monitor invasive species where appropriate within its range.

Citation:	BirdLife International 2008. Gorsachius goisagi. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 24 May 2012.
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