Alternative name: Water Dikkop
Photo © by rudydbn
Location: Isipingo, KwaZulu-Natal Province, South Africa, 4 November 2004
- Burhinus vermiculatus
Identification
38–41 cm (15-16"); 293–320 g.
Adult has pale grey panel on the folded wing, upwards delimited by white and dark. Face pattern with broad white stripe from base of bill to below large yellowish eye, dark malar and white chin and throat. Upperparts streaked, not spotted. In flight shows pale gray wing panel on upperside and has both primary and secondary coverts tipped black. Sexes alike.
Juvenile has more vermiculated upperparts and has buff freckling on its wing coverts .
Similar species
Spotted Thick-knee lacks the pale wing panel and has upperparts spotted, not streaked. Senegal Thick-knee has the wing panel but is is upwards only limited by dark (no white) wing bar, and usually is more strongly limited by black on the lower side; underside of wing shows black tips only to primary coverts. Eurasian Thick-knee if overlapping in range would have a narrower pale panel bordered above by black-white-black.
Distribution
Sub-Saharan Africa.
Taxonomy
This is a polytypic species varying mainly in bill length and upperpart color.
Subspecies
There are two subspecies[1].
- B. v. buettikoferi - Liberia to Nigeria and Gabon; sometimes claimed to occur E to Uganda; darker brown, less gray above, longer bill than nominate.
- B. v. vermiculatus - Democratic Republic of the Congo east to south central Somalia, and south to eastern and southern South Africa; paler, grayer above, shorter billed than B. v. buettikoferi.
Habitat
Riverbanks and lake edges, estuaries and mangroves; also occasionally undisturbed, sheltered beaches.
Behaviour
The Water Thick-knee, like the other Thick-knees, is mainly nocturnal. It is, however, more active during the day than the rest of its genus, when it can be found on river and lake edges. This is particularly true when the weather is dull and overcast.
Diet
Feeds on wide range of prey, including crabs, aquatic beetles, frogs, insects, molluscs and small fish. Nocturnal and terrestrial feeder; sometimes feeds on dirt roads at night.
Breeding
Season variable, but generally dry season and early rains in S Africa; Sept–Jan in Liberia; Jan, Apr and May in Ghana; Aug in Somalia. Monogamous. Nest a shallow scrape in sand, often among debris.
Vocalisation
Mainly vocalizes at night. Call is a far-carrying, loud, rather strident but plaintive whistle, “ti-ti-ti-ti-ti-tee-teee-teeee' fading towards the end.
Movements
Sedentary, apart from some local movements to avoid flooding and occasional records outside normal range.
References
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2017. The eBird/Clements checklist of birds of the world: v2017, with updates to August 2017. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
- Hockey, PAR, WRJ Dean, and PG Ryan, eds. 2005. Roberts' Birds of Southern Africa. 7th ed. Cape Town: John Voelcker Bird Book Fund. ISBN 978-0620340533
- Hume, R. & Kirwan, G.M. (2018). Water Thick-knee (Burhinus vermiculatus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/53768 on 6 July 2018).
- Sinclair, I., Hockey, P.A.R., and Arlott, N. (2005). The Larger Illustrated Guide to Birds of Southern Africa. Struik, Cape Town. ISBN 978-1775840992
- Birdforum thread discussing id of Water vs Senegal Thick-knee
Recommended Citation
- BirdForum Opus contributors. (2024) Water Thick-knee. In: BirdForum, the forum for wild birds and birding. Retrieved 27 April 2024 from https://www.birdforum.net/opus/Water_Thick-knee
External Links
GSearch checked for 2020 platform.1
