Olive and Karoo Thrush, some guidelines for Identification in South Africa.
Etienne Marais(with thanks to Mostert Kriek and Hugh Chittenden)Posted 11 January, 2007
Introduction
Karoo Thrush and Olive Thrush were split on the basis of genetic work conducted a few years ago. However fieldguides have been rather vague and even error-prone in attempting to guide birders in relation to the identification of these related species.
Karoo Thrush (Turdus smithi) occurs in the interior of the country (Gauteng, North-west, western Mpumalanga, Free-state and the drier interior regions of Eastern Cape and Western Cape, as well as the Northern Cape) It is generally a bird of riverine habitat in drier areas, but has adapted well to urban areas and is a common garden bird in many towns across the region (being particularly common in Johannesburg and Pretoria). This species is typically grey-brown, with a grey vent, yellow bill and yellow or orange-yellow eye-ring. The flanks are greyish or grey-brown and the orange-rufous colouring is confined to the centre of the belly.
Key ID Features:
Grey flanks,
Yellow or Orange Eye-ring
,
Plain yellow bill without dark base to upper mandible
Throat usually off-white or dusky, streaks olive-grey or light brown giving the effect of less heavily streaked throat (variable)
Olive Thrush (Turdus olivaceus) occurs along the escarpment, eastern mpumalanga, eastern limpopo and eastern cape, as well as along the coastal region from Cape Town northwards. It is found in and around forest patches in the eastern and southern parts of the country. It also occurs in plantations, gardens and in riverine vegetation. Olive Thrush is generally darker above than Karoo Thrush, with a whiter, better marked throat, and more extensive orange colouration which extends onto the flank. The bill is yellow, but there is a distinctive dark smudge at the base of the upper mandible. The eye ring is brown, and the undertail is typically white.
Key ID Features:
Orange flanks
Brown (dull) Eye-ring
,
Yellow bill with dark base to upper mandible
Throat usually white with dark streaking. Throat appears more heavily streaked than Karoo.
Olive Thrush image from Eshowe Forest, Eshowe (Hugh Chittenden)
Karoo Thrush image from Centurion, Gauteng (Etienne Marais)
Olive Thrush image from the Drakensburg (Hugh Chittenden)
Karoo Thrush image from Centurion (Etienne Marais)
Olive Thrush image from Harrismith (Dave Weaver)