The White-eared Night Heron (Gorsachius magnificus) got its name from not only its appearance, but also its preference for nocturnal activity- this bird is primarily active at night time and rarely ventures from its roosting site prior to sunset. The White-eared Night Heron was first discovered in the 1890s on Hainan Island, Wuzhi Shan, Qiongzhong County, China (Fellowes et al 2001). Since then, confirmed records of white-eared night heron have been sparse and scattered throughout China and Vietnam. From 2004-2006 the largest population was documented in the Thousand Island Region in southeast China (Li et. al. 2007). In 1988, Gorsachius magnificus was catagorized as a threatened species, and by 1994 it was declared to be a critically endangered species by the IUCN. This label lasted until 2000 when the category was changed to endangered, as it has remained until present. Currently, little is known about the global species abundance, but it is considered to be endangered verging on critically endangered.
A white wedge-shape patch extending from the eye gives the species its name. These are smaller herons, with males only getting to be about 55cm tall and females are even smaller. Being located near streams, rice fields, and marshes these herons mostly feed on small fish, shrimp, and other invertebrates (Birdlife Species Champion, 2012). During night they like to forage singly or in isolated pairs near the ground (IUCN-SSC Heron Specialist Group, 2011).
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2014. The eBird/Clements checklist of birds of the world: Version 6.9. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
White-eared Night Heron have been observed primarily in subtropical and tropical regions of south-east China over the last century. After the initial discovery of the White-eared Night Heron on Hainan Island, Wuzhi Shan Province, China in 1890, its known range spread into the surrounding mountains, where the skin of a White-eared Night Heron specimen was collected in March 1899 (He et al., 2011). The next recorded sighting of a White-eared Night Heron was in July of 1901 in Huoshan County of Anhui Province, China. In January of the following year, a female was sighted in Chongyang County of Hubei Province just west of the sighting in Anhui. A male White-eared Night Heron was next collected near Fuzhou County of Fujian Province, China in October of 1911, with sightings of a pair in 1913. Another pair was identified near Lingshi Si County of Fujian Province in the summer of 1929. In April of that same year, a male White-eared- Night Heron was collected in Dayao Shan Nature Reserve in Guangxi Province, China. In December of 1944, a female was spotted again in Fujian Province in Shaowu County. White-eared Night Heron were first recorded to have dispersed into Tianmu Shan County of Zhejiang Province in May of 1954 when a male and female pair was spotted. Three years later, a female was spotted, in this same County in July of 1957. Huashi Shan of Guangdong Province recorded a sighting of a male White-eared Night Heron in March of 1960(BirdLife International, 2012). In April of 1961, a female was sighted in Baisha county on Hainan Island for the first time since 1899 and was last recorded to be on Hainan in 1962 (BirdLife Species Champion 2011). In 1975, the first record of White-eared Night Heron was made in northern Vietnam, near Son Tay in Ha Tay Province. Sightings in the 1990s included three within the Nanning District of Guangxi Zhuang Autonomous region in June 1990, October 1992, and January 1993 and several in Shennongjia Nature Reserve of Hubei Province between 1993 and 1999(Fellowes 2001). Several White-eared Night Herons were also collected in Chebaling Nature Reserve in Quangdong Province between 1993 and 2000 including 4 juveniles and at least 4 different adults (Birdlife International 2012). After 25 years without records in Vietnam, a White-eared Night Heron was observed in Back an Province in 2001. The Thousand Island Lakes region of Zhejiang Province of China was found for the first time to house a small population of White-eared Night Herons in May of 2004, when 6 adults and 4 juveniles were identified. Over the next three years, six nests and sixteen eggs were recorded with thirteen nestlings surviving to fledging and a total of seven breeding pairs (Li et al., 2007). Most recently, reports of a White-eared Night Heron in Bac Kan Province of Vietnam were made in 2008 and 2009 (Pilgrim 2009). It has been suggested that dispersal occurred to the north prior to southern movement and that Hainan is or was once a wintering area for birds from further north ( IUCN-SSC Heron Specialist Group, 2011).
The White-Eared Night Heron (Gorsachius magnificus) is a medium-sized brown heron with a brown streaked breast and a white patch on the side of its head. The male adult exhibits the most profound markings, having a black crown with a brown-black crest and the remainder of the head patterned in white and brown patches. A white wedge-shaped patch extends back from the eye, separating the brown black cheek patch extending from the crown to the bill from the cap. A narrower white line descends diagonally from the eye, and the chin and upper throat are white (Pilgrim et al 2009). The white feathers have dusky centers, giving the white patches a mottled appearance. The lores and skin around the eye are yellow green, and the irises are a dark yellow. The upper bill is black while the lower bill is also black with a green-yellow tinge at the base. The front of the throat has a vertical streak down its middle and is blacker towards the head and browner descending onto the breast. Moving from the side to the back of the neck are three patches: lateral to the central throat stripe is a white line descending from the white lower cheek, a broad black-brown line ascends from the dark shoulder, and a broad buff yellow patch merging to chestnut orange is at the very rear of the neck sides. The upper back is dark grey-brown with a slightly purple tinge, occasionally having a few white spots on the lower back. Flight feathers are slate, thighs are a dark reddish-brown, and the legs are green. The underside of the breast is a mottled brown and white (Heron Specialist Group 2011). Average length of adult males is approximately 54-56 cm (BirdLife Champion 2011).
Females have less prominent coloring on the head and neck, while the back and wings have a more mottled appearance, with a higher occurrence of white spots and streaks, particularly on the upper wing. Female crest feathers are shorter than the males. Juvenile White-Eared Night Herons have predominantly brown feathering spotted with buff or white (Heron Specialist Group 2011).
Average length of adult males is approximately 54-56 cm (BirdLife Champion 2011).
Distinguishing features of the White-eared Night Heron include its dark base color contrasting with white ears and throat, and a short bill length (King, 2005). Common look-a-likes include the Malayan Night Heron (Gorsachius melanolophus) and the Black Bittern (Ixobrychus flavicollis). It also could be mistaken for Little Heron (Butorides striatus) and Chinese Pond Heron (Ardeola bacchus) (Pilgrim et al. 2009). The White-eared Night Heron can be distinguished from the Malayan Night Heron by its tricolored neck, darker sides, and slate flight feathers (Heron Specialist Group 2011). Additionally, White-eared Night Herons can be distinguished from Black Bitterns by their shorter, thicker bill, shorter neck, short foot projection beyond the tail tip and stouter appearance (King, 2005). Light Heron (Butorides striatus) can be distinguished by its smaller size (41-47cm) and slate-grey with some greenish gloss colored head crest and back of neck (Wang, 2007). The Chinese Pond-Heron (Ardeola baccus) can be distinguished by its red-brown head and neck and yellow bill (Avibirds 2012). Another look alike is the Black crowned Night Heron, Nycticorax nycticorax (Pilgrim et al. 2009).
Habitat and Ecology
White-eared Night Herons prefer to roost in areas near extensive primary and secondary forests, with streams, rice fields, marshes and mountains (Fellowes et. al. 2001). Though the optimal habitat for the species is primary forest with adjoining rice fields, marshes and slow-flowing streams that constitute good areas for foraging, pristine habitat is not essential. In the evening, White-eared Night Herons roost in high trees near a source of water and often in or directly adjacent to subtropical forests (Li et al. 2007). While White-eared Night Herons are active at night for foraging and movement, during the daytime birds retreat into the forest, usually within 500m of streams or inundated fields (Fellowes et. al 2001). Due to the lack of forests remaining in low-lying flat areas, recent recordings of White-eared Night Heron report them almost exclusively from hilly and lower to middle mountainous areas, though they have generally been recorded below 1300 m altitude (Fellowes et al 2001). Gorsachius magnificus likes to roost in high trees in the evening, near streams and rivers, reservoirs and paddy fields, in or adjacent to subtropical forests on the lower and middle slopes of mountains (IUCN-SSC heron specialist group, 2011).
White-eared Night Herons have recently started moving into areas of secondary pine (Pinus halepensis) (average 11m in height) forest in the Thousand Island Lakes subtropical monsoon zones of China, presumably due to habitat degradation (Li et. al. 2007). This report from the Thousand Island Lakes region indicates that White-eared Night Heron prefer isolated habitats on smaller islands of approximately 2000-6000 m2, with few other individuals of the species present(area was claimed to be a reservoir in 1959 once dam was built). The islands are in close range, with the nearest-island distance of about 100 m (Li et. al. 2007). Other confirmed roosting sites of White-eared Night Heron in secondary forest include Nahuang Cun, Nazao Cun and Chebaling, within 40 km of areas of extensive primary forests (Fellowes et. al. 2001). In Nahuang Cun, White-eared Night Herons have been reported to roost in young broadleaf trees, including Breynia fruticosa, Litsea glutinosa, Cinnamomum porrectum, and Macaranga denticulate (Fellowes 2001). Here the area is a shallow ravine on shrub-covered hillside and is within 500m of paddy fields and a stream. They have known to nest in oak (Quercus acutissima) in Hubei Province, and bamboo forest and pine in Fujian Province. Nesting has taken place in Pinus massoniana plantation 50m from wide stream, placed 7-10m above ground in 10-12m tall trees (Birdlife International, 2001).
The White-eared Night Heron is believed to be a summer visitor to the northern-most parts of its range. In October, the White-eared Night Heron appearently moves south to winter in Hainan as well as south-east Asia. The White-eared Night Heron has been recorded in Hubei and Guangxi, (possibly non-migratory in Guangxi) as late as January, Guangdong in March as well as Fujian in December and March, which indicates that its migratory status is still questionable. The White-eared Night Heron is also suggested to be a migrant to northern Vietnam, being primarily spotted in the Bac Kan Province in March and early April (Pilgrim 2009). Migratory status is still questionable, but the IUCN classifies this heron as a full migrant (IUCN Red List Criteria fact sheet, 2012).
The White-eared Night Heron is common among subtropical and tropical regions of south-east China and northern Vietnam. Most sightings were in reserves, farms, and markets (last sighting in 2005).
Dated sightings: Hubei-Shennongjia Nature Reserve(1902, 93-99), Anhui (1901-02), Zhejiang (1954-early 60s), Guangdong-Chebaling National Nature Reserve (1960, 1993-00), in the mountains of Hainan Island (1899, 1961-62), and finally Ban Thi-Xuan Lac (1975)(Birdlife International, 2012).
Historical sightings: In 1990, 1992, and 1993 there was known sightings of the White-eared Night Heron within the Nanning District of Guangxi Zhuang Autonomous Region (Longhushan, Xianhu Reservoir & Nada, and Loxu). 1994 had five sightings within the District’s Damingshan Nature Reserve. 1998 Nanning and Shixing County had one each. 1999 Duheng Village had two found in a farm by a main stream. Three injured ones were found this year near Nahuang Cun, Fusui County; Datang Village; and Fengtinghe Reservoir. In Guangxi and Shajing town (suburb of Nanning) had two for sale in the market (Fellowes, J., et. al. 2001 and Fen-Qi. et. al. 2007).
More recent sightings: In 2000 nesting sites were found by a stream in Nazao within a Pinus massoniana plantation. Also more nesting sites found in Nahuang Cun of this year and more in Biannian Village, Guangxi and near Chebaling National Nature Reserve, Guangdong (sightings). Suspicion of more populations due to historical sightings: Guangxi, Guangdong, Hainan, Hunan, Jiangxi, Fujian, and Zhejiang, but not confirmed (Fellowes, J., et. al. 2001). There is a known population of a u-shape within the (NE)Hunan and (NW)Jiangxi provinces, but connectivity is lacking within these locations.
Sightings Elsewhere: Dayao Shan Nature Reserve, Houhe Nature Reserve, Huashui Shan, Jianfengling Nature Reserve, Jiulianshan Nature Reserve, Jiangkou Xiang-Mashi Zhen, Longhu Shan, Pingnan Dapeng, and Qiandao Hu Reservoir (IUCN Red List Criteria Factsheet, 2012). Vietnam includesBa Be National Park and Na Hang Nature Reserve(Birdlife Species Champion, 2011).
Chinese Provinces: Hunan, Zheijian, Jiangxi, Xinping, Yunnan, Guizhou, and Sichuan in China, Bac Kan and Tuyen Quang in Vietnam(Birdlife Species Champion, 2011).
It is believed that dispersal occurred to the north prior to southern movement and that Hainan is or was once a wintering area for birds from further north (IUCN-SSC Heron Specialist Group, 2011).
It is known that the White-eared Night Heron breeds and is probably a resident of Northern Vietnam (Pilgrim et al. 2009).
These herons mostly eat small fish, shrimp, and invertebrates (Pilgrim et. al. 2009).
Populations have been estimated to be between 250-999 adults as of 2005. China has been estimated to have less than 100 breeding pairs. Between Vietnam and China, the total number of White-eared Night Herons is estimated to be between 350-1500 individuals (BirdLife Species Champion, 2012).
Life History and Behavior
The herons are silent when flying to the feeding grounds at night (Fellowes et. al. 2001). They are known to breed in pairs. When a nest is established one heron keeps the egg warm while the other stands on a branch nearby as a sentinel (Li et al., 2007).
The territorial call of this heron is a deep-throaty, raspy "whoa" that lasts for about 0.3 seconds. This call gets as loud as 0.2-0.5kHz and it is repeated every 5-15 seconds. King (2005) describes this call as similar to that of a large owl.
Juvenile White-Eared Night Herons have predominantly brown feathering spotted with buff or white (Heron Specialist Group 2011). When they become adults they have more spots on their chest, and some orange on the neck. Their body is a dark brown and the crown is black (Pilgrim et al. 2009).
Females begin to carry eggs as early as the start of March and lay eggs towards the end of April. After the 25 day incubation period, eggs hatch in early May (usually between the 3-13th). Fledglings and young birds are observed in June and are considered juveniles by mid-August (Pilgrim 2009).
White-eared Night Heron (Gorsachius magnificus) breeding strategies have been most thoroughly examined in the Thousand Island Lake region, Zhejiang Province, P.R. China. In the Thousand Island Lake region, no more than one Gorsachius magnificus nest was observed per island per breeding season and no other heron species nested or colonized the same island where the White-eared Night-heron nested. White-eared Night-herons are solitary nesters and do not nest in heronries like most heron species. Nesting islands were relatively small. The White-eared Night Heron builds their nests with thin pine branches. Nest building can take two weeks’ time. The White-eared Night Heron forms a disk shaped nest high in the pine tree, no higher than 7m from the ground. The construction of the nest occurred over a two week period. Thin withered pine branches were arranged to form a disk-like external rim to the nest, with diameters ranging from 25-70 cm. They position their nest on two crossing branches with the main branch being as parallel to the ground as possible. The nests also need to be within 5-8m of a water front. Eggs are an ovoid shape with white speckles on a pale blue background. Eggs averaged a size of 6.5cm long and 3.5cm wide. Incubation period is about 25 days long. Clutch size is 3-5. Nestlings hatch consecutively and (at this particular study area) all nestlings survived to fledge. During breeding the adult Herons take turns incubating the young and foraging at night. During the day one heron typically is in the nest and the other is on a nearby branch. At night, one adult leaves the nest to gather food from nearby water sources and promptly returns to the nest to feed nestlings. Breeding in Daming Shan Mountains in Guangxi, China occurs at 1200m and the birds winter at altitudes below 500m. Nests are 4-10m above ground positioned against the trunks, 2m from tree tops.
Other confirmed White-eared Night-heron nesting sites include Nahuang Cun, South China and Chebaling National Nature Reserve. Both of these nesting sites were in secondary forests no more than 40km from areas of primary forest (Fellowes et al. 2001). White-eared Night-heron has also been observed as a breeding species in a low-integrity plantation forest in Nanning (BirdLife Species Champion 2011).
A White-eared Night-heron nestling was caught swimming in the Gam reservoir in the Na Hang Nature Reserve in Vietnam on May 5, 2008 indicating the Na Hang Nature Reserve as a breeding site of at least one pair. The caught heron was photographed as a juvenile in early June of 2008 (Walsh 2008).
Molecular Biology and Genetics
Little is known about the genetic compostion of the White-eared Night Heron. The only known genes to have been sequenced are the MHC class II antigne beta gene alleles.
Gorsachius magnificus MHC class II antigen beta (Goma-DAB1) gene, Goma-DAB1*01 allele, exons 2, 3 and partial cdsLOCUS: HM991024 656 bp DNA linear VRT 14-OCT-2011ORIGIN 1 gttttccagg aattctctac gtttgagtgt cactacctga acggcaccga gcgcgtcagg61 tttttgcaca ggtacatcca caaccggcag cagctctcac acttcgacag cgacgtgggg 121 ctccatgtgg ccgacagccc cctgggcgag tccattgcca agtactggaa cagccagacg181 gccatactgg aggacagacg ggctgctgtg gacaggttct gcagatacaa ctacggggtg241 tcgacccctt tctctgtgga taggaggggt gagcgcgtgg cagaacattt ccctggggga301 tgggcacagg ccaagcctcc gggctcgcgg gaggggagag cgtggccgtg tcggcctcgg361 gcagggcccc gggcgagcaa agcccctgcg tccttccatg aggacacgag tccctcacac421 cctccctggg cacgcctggc gtgggcacca cagggacagc cctgggccag gctggggggt481 ccctgtgctc tcccagctcc tccccagcat gcgctcactc tcccccagtt cagcccgagg541 tggaaatcta cccgatgcag tcgggctccc tgccccagac tgacaggctg gtttgtgccg601 tgatggattt ctacccggcg gagattgagg tgaagtggtt caagaacggg caggag
Gorsachius magnificus MHC class II antigen beta (Goma-DAB2) gene, Goma-DAB2*01 allele, exons 2, 3 and partial cds
LOCUS HM991048 656 bp DNA linear VRT 14-OCT-2011ORIGIN 1 tatctacagt tccagtttaa gtgcgactgt tactacacca atggcaccga gcgggtgaag61 tatgtgaaga ggtacatcca caaccggcag cagctcgtgc acttcgacag cgatctgggg121 ctccatgtgg ccgacagccc cctgggcgag tccattgcca agtactggaa aagtcagcca181 gacatactgg agaatgacct ggctgaggtg gacagggtct gccgaaacaa ctacagggtg241 tcgacccctt tctctgtgga taggagaggt gagcgcgtgg cagaacattt ccctggggga301 tgggcacagg ccaagcctcc gggctcgcgg gaggggagag cgtggccgtg tcggcctcgg361 gcagggcccc gggcgagcaa agcccctgcg tccttccatg aggacacgag tccctcacac421 cctccctggg cacgcctggc gtgggcacca cagggacagc cctgggccag gctggggggt481 ccctgtgctc tcccagctcc tccccagcac gcgctcactc tcccccagtt cagcccgagg541 tggaaatcta cccgatgcag tcgggctccc tgccccagac cgacaggctg gtttgtgccg601 tgatggattt ctacccagcg gagattgagg tgaagtggtt caagaacggg caggag
Gorsachius magnificus MHC class II antigen beta (Goma-DAB1) gene, Goma-DAB1*02 allele, exons 2, 3 and partial cdsLOCUS HM991025 656 bp DNA linear VRT 14-OCT-2011ORIGIN 1 gttttccagg aattctctac gtttgagtgt cactacctga acggcaccga gcgcgtcagg61 tttttgcaca ggtacatcca caaccggcag cagctctcac acttcgacag cgacgtgggg121 ctctatgtgg ccgacagccc cctgggcgag tccattgcca agtactggaa cagccagacg181 gccatactgg aggacagacg ggctgctgtg gacaggttct gcagatacaa ctacggggtg241 tcgacccctt tctctgtggg taggagaggt gagcgcgtgg cagaacattt ccctggggga301 tgggcacagg ccaagcctcc gggctcgcag gaggggagag cgtggccgtg tcggcctcgg361 gcagggcccc gggcgagcaa agcccctgcg tccttccatg aggacacgag tccctcacac421 cctccctggg cacgcctggc gtgggcacca cagggacagc cctgggccag gctggggggt481 ccctgtgctc tcccagctcc tccccagcac gcgctcactc acccccagtt cagcccgagg541 tggaaatcta ccagatgcag tcgggctccc tgccccagac cgacaggctg gtttgtgccg601 tgatggattt ctacccggcg gagattgagg tgaagtggtt caagaacggc caggag
Gorsachius magnificus MHC class II antigen beta (Goma-DAB2) gene, Goma-DAB2*02 allele, exon 2 and partial cds
LOCUS HM991049 270 bp DNA linear VRT 14-OCT-2011ORIGIN 1 tatctacagt tccagtttaa gtgcgactgt tactacacca atggcaccga gcgggtgaag61 tatgtgaaga ggtacatcca caaccggcag cagctcgtgc acttcgacaa cgatctgggg121 ctccatgtgg ccgacagccc cctgggcgag tccattgcca agtactggaa aagtcagcca181 gacatactgg agaatgacct ggctgacgtg gacagggtct gccgaaacaa ctacagggtg241 tcgacccctt tctctgtgga taggagaggt
(Li, L. et. al. 2011)
IUCN Red List Assessment
Red List Category
Red List Criteria
- 2012Endangered (EN)
- Endangered (EN)
- Endangered (EN)
- Endangered (EN)
- Endangered (EN)
- Endangered (EN)
- Critically Endangered (CR)
- Critically Endangered (CR)
- Threatened (T)