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Water Thick-knee Burhinus vermiculatus
BirdLife is updating this factsheet for the 2016 Red List
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This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size may be moderately small to large, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Taxonomic source(s)
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

Trend justification
The population trend is difficult to determine because of uncertainty over the extent of threats to the species (del Hoyo et al. 1996).

Behaviour This species is largely sedentary although some individuals may make local movements to avoid river flooding (returning to exposed riverbanks as the water recedes) (del Hoyo et al. 1996). The timing of breeding is variable but generally coincides with the dry season or the early rains, with the species nesting solitarily (del Hoyo et al. 1996) or in loose associations of several pairs on riverine sandbars (Hockey et al. 2005). The species is usually observed foraging nocturnally (del Hoyo et al. 1996) in pairs or small groups (Hayman et al. 1986) but is also gregarious at times, gathering in flocks of 30 or more individuals during the non-breeding season (Urban et al. 1986). Habitat It inhabits riverbanks, lake shores, estuaries, mangrove swamps, undisturbed sheltered beaches (del Hoyo et al. 1996) and the shores of coastal creeks and islands (Hayman et al. 1986), showing a preference for habitats with bushes or shrubs providing cover (e.g. light woodland) (del Hoyo et al. 1996). It generally avoids heavily vegetated wetlands (Hockey et al. 2005) but occasionally forages more than 1 km from water (del Hoyo et al. 1996). Diet Its diet consists of insects (del Hoyo et al. 1996) (e.g. aquatic beetles, grasshoppers, locusts and termites) (Hockey et al. 2005), crustaceans (del Hoyo et al. 1996) (e.g. crabs with carapace widths of up to 50 mm) (Hockey et al. 2005), molluscs (del Hoyo et al. 1996), worms, frogs and tadpoles, millipedes and grass seeds (Hockey et al. 2005). Breeding site The nest is a scrape in the ground often positioned close to water (del Hoyo et al. 1996) on a sandbank, shoreline (Urban et al. 1986) or a small islet (Hayman et al. 1986) near a landmark such as a piece of driftwood or a bush (del Hoyo et al. 1996).

The species is threatened by human disturbance and predation by domestic dogs on beaches (Hockey et al. 2005).

del Hoyo, J.; Elliott, A.; Sargatal, J. 1996. Handbook of the Birds of the World, vol. 3: Hoatzin to Auks. Lynx Edicions, Barcelona, Spain.

Delany, S.; Scott, D. 2006. Waterbird population estimates. Wetlands International, Wageningen, The Netherlands.

Hayman, P.; Marchant, J.; Prater, A. J. 1986. Shorebirds. Croom Helm, London.

Hockey, P. A. R.; Dean, W. R. J.; Ryan, P. G. 2005. Roberts birds of southern Africa. Trustees of the John Voelcker Bird Book Fund, Cape Town, South Africa.

Urban, E. K.; Fry, C. H.; Keith, S. 1986. The birds of Africa vol. II. Academic Press, London.

Further web sources of information
Explore HBW Alive for further information on this species

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Ekstrom, J., Butchart, S., Malpas, L.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2016) Species factsheet: Burhinus vermiculatus. Downloaded from on 28/10/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from on 28/10/2016.

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

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Least Concern
Family Burhinidae (Thick-knees)
Species name author (Cabanis, 1868)
Population size mature individuals
Population trend Unknown
Distribution size (breeding/resident) 5,800,000 km2
Country endemic? No
Links to further information
- Additional Information on this species
- Projected distributions under climate change