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Great Knot

Common Name Great KnotBirdlife International
Species name Calidris tenuirostrisBirdlife International
Family Scolopacidae
Genus  
Local Name
Country Appearance Local name
Brunei Darussalam    
Cambodia    
China    
Indonesia    
Japan Yes オバシギ
Lao PDR    
Malaysia    
Mongolia    
Myanmar    
Philippines    
Republic of Korea    
Singapore    
Thailand    
Vietnam    

 

Visual and Sound Image

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Great Knot

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Sounds

 

Identification

No descriptions

Birdlife International

 

Range Description

Calidris tenuirostris breeds in north-east Siberia, Russia, wintering throughout the coastline of South-East Asia, and also on the coasts of Australia, India, Bangladesh, Pakistan, and the eastern coast of the Arabian Peninsula1. The global population has been estimated at 380,000 individuals, of which 176,000 were thought to pass through South Korea10. Since then the reclamation and development of wetlands in South Korea has led to a decline in the observed counts of non-breeding populations, mostly notably including dramatic declines at the Saemangeum wetland which previously held c.20-30% of the global population on migration13,14. Despite there being no observed declines within the Chinese portion of the Yellow Sea, further declines at smaller staging grounds in Japan and at major wintering grounds in Australia make it clear that the population is declining overall11,12,16.

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Ecology

Ecology (Behaviour)

This species is a long-distance migrant that largely travels along the coast making few stopovers1 but utilising different routes in the autumn and the spring1, 5. It breeds from late-May to late-June, departing the breeding grounds in July and arriving on the wintering grounds between August and October1. The return migration to the breeding grounds takes place from March to April1 although juvenile non-breeders often remain in the tropical parts of the wintering range for the breeding season2. The species forages in large flocks of one hundred to several thousand1 at favoured sites on passage2, but during the winter it typically forages in small groups3.

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Habitat

<Breeding> The species breeds on gravelly areas covered with lichen and patches of herbs, heather1, Empetrum spp., Dryas spp. and Vaccinium spp.3, or alternatively on areas with a continuous layer of lichen and scattered stunted larch Larix spp. or dwarf pine Pinus pumila1. It occurs on plateaus or gentle slopes with montane tundra in the subarctic at heights of 300-1,600 m1.
<Non-breeding> In its wintering range the species occurs in sheltered coastal habitats such as inlets, bays, harbours, estuaries and lagoons with large intertidal mud and sandflats, oceanic sandy beaches with nearby mudflats1, 5, sandy spits and islets, muddy shorelines with mangroves and occasionally exposed reefs or rock platforms5. It roost in refuges6 such as shallow water in sheltered sites, on coastal dunes or on saltflats amongst mangroves5 during high tides6. On passage the species stages in estuaries and on intertidal mudflats7, 8.

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Diet

<Breeding> The adult breeding diet consists predominantly of plant material such as berries1 (e.g. of Empetrum nigrum)3 and pine kernels of dwarf pine Pinus pumilla1. Small chicks feed exclusively on insects (e.g. larval Diptera and Coleoptera) and spiders1.
<Non-breeding> During the winter and on passage the species takes bivalves up to 36 mm long from intertidal mudflats as well as gastropods, crustaceans1 (e.g. crabs and shrimps)5, annelid worms and echinoderms (e.g. sea cucumbers)1.

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Breeding Site

The nest may be an open depression in moss4, but very few nests have been found3.

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References

1. del Hoyo et al. (1996). 2. Hayman et al. (1986). 3. Johnsgard (1981). 4. Flint et al. (1984). 5. Higgins and Davies (1996). 6. Rogers et al. (2006). 7. Moores (2006). 8. Tomkovich (1997). 9. Kelin and Qiang (2006). 10. Wetlands International (2006). 11. Moores et al. (2008). 12. Amano (2006). 13. Moores in litt. (2009). 14. Rogers et al. in litt. (2009). 15. BirdLife International (unpublished data). 16. R. Clemens in litt. (2010).

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Status

International Status

IUCN Red List Category

VU

Justification

This species has been uplisted to Vulnerable owing to a rapid population decline caused by the reclamation of non-breeding stopover grounds, and under the assumption that further proposed reclamation projects will cause additional declines in the future.
<Population justification> The global population has been estimated at c.380,000 individuals (Wetlands International, 2006). Following the reclamation of the tidal flats at Saemanguem, c.90,000 non-breeding individuals disappeared from the area. Surveys elsewhere in South Korea confirmed they had not been displaced, and a decline of the same magnitude and timing in Australia suggests that individuals previously using Saemanguem have died (D. Rogers in litt. 2009). Therefore a population of c.290,000 individuals is estimated, though given documented declines elsewhere the true figure is likely to be lower.
<Trend justification> Reclamation of Saemangeum alone has caused a decline of c.90,000 individuals, equating to a population decline of approximately 25% since 2000 (N. Moores in litt. 2009; D. Rogers in litt. 2009). Furthermore there have been documented declines in some of the peripheral sites for the species in Australia and Japan (Amano 2006; R. Clemens in litt. 2010). Given that reclamation in the Yellow Sea is not restricted to Saemangeum and many more reclamation projects are proposed within the region, it is reasonable to assume that declines will continue in the future, hence a precautionary decline of 30-49% over 22 years (three generations) is estimated.

 

National Status

Country Category Reference
Brunei Darussalam    
Cambodia    
China    
Indonesia    
Japan    
Korea    
Lao PDR    
Malaysia    
Mongolia    
Myanmar    
Philippines    
Singapore    
Thailand    
Vietnam    

 

Management

Threat

In the Chinese, North Korean and South Korean regions of the Yellow Sea (a major stopover area) the species is threatened by the degradation and loss of wetland habitats through environmental pollution9 (e.g. oil contamination of intertidal mudflats)8, reduced river flows and human disturbance9 (e.g. from off-road vehicles, tourists and hunters)8. In South Korea, after the loss of the important Saemangeum stopover area and almost all of the tidal-flats in Asan Bay and much of Namyang bay, possibly only five sites nationwide remain internationally important. Of these, only one (the Geum Estuary) currently has a low risk of reclamation, with the other four at risk due to the construction of tidal power plants and barrages, industrial use and urban expansion13. The species is also potentially threatened by climate change because it has a geographically bounded distribution: its global distribution is restricted to within c.10o latitude from the polar edge of continent and within which 20-50% of current vegetation type is projected to disappear under doubling of CO2 levels15.

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Information

No descriptions

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Current Conservation

No specific conservation action is known for this species, although population trends are being monitored in Australia as part of the Monitoring Yellow Sea Migrants in Australia project.

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Current Conservation

Identify key stopover areas and prevent their reclamation. Continue to monitor population trends. Restore reclaimed wetland sites. Campaign to stop shorebird hunting in Asian countries. Legally protect it in all range states. Survey the breeding grounds for potential threats. Manage roost sites in the species's Australian wintering range to minimise disturbance6.

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Legal Protection

Country Status Reference
Brunei Darussalam    
Cambodia    
China    
Indonesia    
Japan    
Korea    
Lao PDR    
Malaysia Protected Wild Birds Part I: Game Birds Law of Malaysia Act 76, Protection of Wild Life Act 1972
(Amend. 2006)
Mongolia    
Myanmar    
Philippines    
Singapore    
Thailand    
Vietnam    

 

Related Links

 

 

Range

Geographical Information

Migration Route

 

Asian Waterbird Census

Descriptions

The Asian Waterbird Census (AWC) was initiated in 1987 and runs in parallel with other waterbird censuses carried out in Africa, Europe, Central and West Asia and Latin America under the umbrella of the International Waterbird Census (IWC), which is organised by Wetlands International.

The AWC takes place annually, during the second and third weeks of January, and is carried out by volunteers interested in collecting information on waterbirds and wetlands as a basis for contributing to their conservation.

Reference: Li, Z.W.D., Bloem, A., Delany S., Martakis G. and Quintero J. O. 2009. Status of Waterbirds in Asia - Results of the Asian Waterbird Census: 1987-2007. Wetlands International, Kuala Lumpur, Malaysia

Census Data

BRUNEI DARUSSALAM 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual       1                                    
The number of observed sites(not all count sites)       1                                    
The total number of count sites 2 3 3 2 4 4 0 4 4 4 4 5 5 0 0 0 9 0 0 1 0 9
CAMBODIA 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual                                            
The number of observed sites(not all count sites)                                            
The total number of count sites 0 0 0 0 0 0 0 4 0 0 11 0 0 12 12 11 5 1 6 9 6 6
CHINA 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual                                     12      
The number of observed sites(not all count sites)                                     1      
The total number of count sites 0 1 34 12 50 60 67 29 6 14 6 15 21 20 14 10 22 45 80 81 59 72
INDONESIA 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual         126   26                   426         650
The number of observed sites(not all count sites)         1   2                   2         1
The total number of count sites 0 0 0 1 19 8 17 17 15 19 16 0 0 47 12 10 40 34 14 16 15 23
JAPAN 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual                                     7 1 1 4
The number of observed sites(not all count sites)                                     1 1 1 2
The total number of count sites 0 0 0 53 39 52 47 20 50 40 47 37 41 37 107 112 103 109 97 159 142 137
LAO PDR 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual                                            
The number of observed sites(not all count sites)                                            
The total number of count sites 0 0 0 2 4 5 3 2 1 0 0 0 0 0 14 1 0 0 0 1 0 0
MALAYSIA 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual       21 80   125 20 479 37       100 43 82 83 1178 656 501 1174 703
The number of observed sites(not all count sites)       2 2   2 2 2 2       1 2 2 1 4 2 3 10 3
The total number of count sites 0 0 0 59 68 93 85 17 10 7 10 0 0 20 25 25 25 43 43 82 82 40
MYANMAR 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual                                            
The number of observed sites(not all count sites)                                            
The total number of count sites 0 5 3 12 17 15 21 20 13 12 2 4 2 0 7 32 47 73 24 31 32 19
PHILIPPINES 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual         10 64 156 332 14   128 145 87   50 73 123 6 663 3 33 401
The number of observed sites(not all count sites)         1 4 6 5 2   1 4 1   3 1 3 1 3 1 1 3
The total number of count sites 0 0 0 0 19 21 34 39 46 47 39 28 29 32 43 38 50 47 56 54 65 108
SINGAPORE 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual                           2                
The number of observed sites(not all count sites)                           2                
The total number of count sites 0 0 0 0 4 12 17 15 13 14 10 10 6 11 10 10 8 9 9 8 8 7
REPUBLIC OF KOREA 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual                                            
The number of observed sites(not all count sites)                                            
The total number of count sites 0 0 10 12 22 20 20 15 10 22 25 22 14 68 99 112 118 116 117 123 127 127
THAILAND 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual 235 3 5       38 66 40         1 52     85 107 133 1681 1590
The number of observed sites(not all count sites) 2 1 1       4 2 1         1 1     2 1 3 6 5
The total number of count sites 10 8 3 20 26 12 23 16 17 5 9 3 1 1 7 3 9 26 20 82 99 33
VIETNAM 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
The number of observed individual                                     145 100 134 36
The number of observed sites(not all count sites)                                     1 1 4 2
The total number of count sites 0 0 0 1 2 0 1 4 0 1 1 0 1 8 2 2 16 4 4 9 6 11

 

Population

Descriptions

 

Population Trend

 

Additional Information

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Climate change species distributions

 

Other Information