Justification of Red List Category
This species is listed as Endangered because it has a very small, fragmented population which is undergoing a continuing decline as a result of hunting and forest clearance, primarily owing to demands for timber and agricultural land. The species may warrant downlisting in the future should data prove that the recent increase in its known range also corresponds to an increase in the known population.
Brazil (2009) has estimated the population in China at fewer than 100 breeding pairs. The global population is estimated at c.250-999 mature individuals (BirdLife International 2001; M. Crosby in litt. 2005). This estimate equates to 375-1,499 individuals in total, rounded here to 350-1,500 individuals. Recent records confirm the species occurs in a wider range than previously thought, and the global population size could be shown to be larger (He Fenqi in litt. 2016), but it is tentatively retained in the current range (J. Kushlan in litt. 2016).
This species's population is presumed to be experiencing a rapid decline owing to hunting and the clearance and fragmentation of forest, primarily owing to demands for timber or agricultural land and damming of some sites for stream regulation.
Gorsachius magnificus is known from southern China and northern Vietnam (BirdLife International 2001). By 2001, the species was known from c.20 localities, but since then extensive survey effort and increased awareness have resulted in records from more than 30 new localities (He Fenqi et al. 2011). There are records from Hunan, Hubei, Zheijian, Anhui, Jiangxi, Guangxi, Xinping, Guangdong, Yunnan, Fujian, Guizhou and Sichuan provinces, and it was last recorded on Hainan in 1962 (Gao Yuren 2003, Kadoorie Farm and Botanic Garden 2003, He Fenqi and Lin Jiansheng 2004, He Fenqi et al. 2007a,b, M. Crosby in litt. 2009, 2016, He Fenqi et al. 2011, He and Jiang 2013, Gao et al. 2013). There are also recent records from northern Vietnam (including Ba Be National Park, Bac Kan province, and Na Hang Nature Reserve, Tuyen Quang province), among them the first and subsequent breeding records for the country (Anon. 2001, Nguyen Cu 2008, Eames and Le Manh Hung 2009, Pilgrim et al. 2009, J. Pilgrim in litt. 2009, Walsh 2010). Direct observations and information from local people suggest that there is a minimum of seven pairs in the Xuan Lac and Ba Be areas of Bac Kan province (Walsh 2010). The degree of connectivity between populations is poorly understood. The rate of discovery of new sites has led to considerable extension of its known range and suggests the species has been under-recorded and may breed across a wider range in southern China and northern Indochina (He Fenqi et al. 2007a,b, 2011). However, significant threats to the species and its habitats remain and as a result a continuing decline is inferred.
Its ecology is poorly known. It occurs in subtropical and tropical forest, with recent records from sites close to streams, rivers, reservoirs and rice-fields (close to or within forest). Its ability to persist in modified habitats is also demonstrated by its presence as a breeding species in a low-integrity plantation forest in Nanning (He Fenqi et al. 2007a) and secondary pine forest on reservoir islands in Zhejiang (per Eames and Le Manh Hung 2009). Its diet includes small fish, shrimps and invertebrates, and it appears to be almost entirely nocturnal (Pilgrim et al. 2009). The species does not nest in heronries and lays 3-5 eggs (Li et al. 2007).
A key threat is forest clearance and fragmentation, primarily as a result of demands for timber and agricultural land in an extremely densely populated region. Although the species can nest in human modified habitats, vulnerability of monocultures to pest invasion is a risk (Fellowes et al. 2001). Human disturbance may cause this secretive bird to abandon eggs while incubating (Li et al. 2007). Hunting is a major additional threat, even inside protected areas, and it may be particularly vulnerable when nesting. The decline or disappearance of the birds in Hubei and parts of Guangxi and Guangdong has been attributed to habitat damage and direct hunting (He Fenqi et al. 2007a). In Guangxi, the number of birds seen in markets outnumbers records in the wild. In recent years, a relatively high number of specimens have been collected, including those to supply scientific purposes, notably at Chebaling and Shennongjia (He Fenqi et al. 2007a). This, like capture for food, is illegal in China. Direct habitat damage for dam construction, river regulation and road building has driven birds from known sites, but counter-intuitively these activities also create new habitats in some cases. It appears that most areas of suitable habitat in Vietnam are subject to pressure from deforestation and hunting (Eames and Le Manh Hung 2009, Pilgrim et al. 2009, Walsh 2010), with overfishing and the intensive use of agricultural chemicals also being widespread (Pilgrim et al. 2009). The impact of chemical pesticides and fertilizers is unknown. Other threats affecting Ba Be National Park, Vietnam, include firewood collection, harvesting of non-timber forest products, occupation of agricultural land within the park, cattle-grazing, water pollution and sedimentation (Eames and Le Manh Hung 2009, Walsh 2010).
Conservation Actions Underway
It is a Class II nationally protected species in China. It has been recorded in or near several protected areas in China, including Shennongjia Nature Reserve (Hubei), Tianmu Shan National Nature Reserve (Zhejiang), Dayao Shan Nature Reserve and Daming Shan Nature Reserve (Guangxi), Chebaling National Nature Reserve (Guangdong), Jianfengling Nature Reserve and Wuzhishan Nature Reserve (Hainan), and Jiulianshan Nature Reserve (Jiangxi) (Tang Pei-Rong and Liao Cheng-Kai 2003). In Vietnam, it has been recorded in Ba Be National Park and Na Hang Nature Reserve (Nguyen Cu 2008, Eames and Le Manh Hung 2009, Pilgrim et al. 2009, J. Pilgrim in litt. 2009, Walsh 2010). Special nature reserves have been created for the species in Fusui and Shangsi, southern Guangxi (Fellowes et al. 2001), of which the former was later merged administratively with the Fusui Precious Animal Reserve protecting the white-headed leaf monkey Trachypitheus poliocephalus. Fieldwork in northern Vietnam in 2008 appears to have raised awareness amongst local people, such that they are now starting to officially report nests (Walsh 2010). A management plan for the species has been produced for Ba Be National Park (Dine 2012).
54-56 cm. Secretive, boldly patterned night-heron. Males have blackish head and nape plumes, white postocular stripe, cheek-stripe and throat, broad blackish line down neck side, brown underparts with whitish streaks/scales and orange-buff to rufous-chestnut rear neck sides. Females have less distinct head and neck pattern, whitish streaks and spots on back and wings (particularly wing-coverts) and shorter nape plumes. Juvenile resembles female, but dark parts of plumage browner, has heavier whitish to buff spots above.
Text account compilers
Benstead, P., Harding, M., Crosby, M., Westrip, J., Peet, N., Bird, J., Calvert, R., Taylor, J.
Pilgrim, J., Hafner, H., Lau, M., Fellowes, J., He, F., Kushlan, J., Crosby, M.
BirdLife International (2019) Species factsheet: Gorsachius magnificus. Downloaded from http://www.birdlife.org on 16/06/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/06/2019.