Olive thrush

Olive thrush
Olive thrush adult, Greyton, South Africa
Song recorded in KwaZulu-Natal, South Africa
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Turdidae
Genus:	Turdus
Species:	T. olivaceus
Binomial name
Turdus olivaceus Linnaeus, 1766

The olive thrush (Turdus olivaceus) is, in its range, one of the most common members of the thrush family (Turdidae). It occurs in African highlands from the montane regions in Eastern and Central Africa in the north to the Cape of Good Hope in the south.[2] It is a bird of forest and woodland, but has locally adapted to parks and large gardens in suburban areas.

Taxonomy

In 1760 the French zoologist Mathurin Jacques Brisson included a description of the olive thrush in his Ornithologie based on a specimen collected from the Cape of Good Hope in South Africa. He used the French name Le merle olive du Cap de Bonne Espérance and the Latin Merula Olivacea Capitis Bonae Spei.[3] Although Brisson coined Latin names, these do not conform to the binomial system and are not recognised by the International Commission on Zoological Nomenclature.[4] When in 1766 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the twelfth edition, he added 240 species that had been previously described by Brisson.[4] One of these was the olive thrush. Linnaeus included a brief description, coined the binomial name Turdus olivaceus and cited Brisson's work.[5]

Six subspecies are recognised:[6]

• T. o. milanjensis Shelley, 1893 – south Malawi and northwest Mozambique
• T. o. swynnertoni Bannerman, 1913 – east Zimbabwe and west Mozambique
• T. o. transvaalensis (Roberts, 1936) – northeast South Africa
• T. o. culminans Clancey, 1982 – east South Africa
• T. o. olivaceus Linnaeus, 1766 – southwest South Africa
• T. o. pondoensis Reichenow, 1917 – southeast South Africa

A juvenile and immature of the nominate subspecies near Cape Town, South Africa

The subspecies differ mainly in the relative amounts of white, orange and brown on the underparts. Several additional populations of African Turdus thrushes were previously included within this group, but are now most commonly treated as separate species in their own right including the Karoo thrush (Turdus smithi), the Somali thrush (Turdus ludoviciae) and the more northerly Abyssinian thrush, also known as the Northern olive thrush and Mountain thrush, T. abyssinicus, itself also sometimes considered as several separate species (Abyssinian thrush, T. abyssinicus, Usambara thrush, T. roehli and Taita thrush Turdus helleri).[2]

Description

It can reach a length of 24 cm (9.4 in) and a weight of at least 101 g (3.6 oz). The tail and the upperparts are coloured dull olive brown. The belly is white and the rest of the underparts have an orange hue. The throat is speckled with white spots. It can be found in evergreen forests, parks, and gardens.

The male's song is a mix of fluted, whistled and trilled phrases, which varies geographically. It occasionally mimics other birds.

Behaviour

The female builds a cup nest, typically 2 to 9 m (6 ft 7 in to 29 ft 6 in) above the ground in a tree or hedge. The 1–3 (usually 2) eggs are incubated solely by the female for 14–15 days to hatching, and the chicks fledge in another 16 days.

Its diet consists of earthworms, insects, snails, fruits, and spiders.

References

1. BirdLife International (2017). "Turdus olivaceus". IUCN Red List of Threatened Species. 2017: e.T103888967A119723556. doi:10.2305/IUCN.UK.2017-3.RLTS.T103888967A119723556.en. Retrieved 12 November 2021.
2. Bowie, Rauri; Voelker, Gary; Fjeldså, Jon; Lens, Luc; Hackett, Shannon; Crowe, Timothy (2005). "Systematics of the Olive Thrush Turdus olivaceus Species Complex with Reference to the Taxonomic Status of the Endangered Taita Thrush T. helleri" (PDF). Journal of Avian Biology. 36 (5): 391–404. doi:10.1111/j.0908-8857.2005.03459.x. Retrieved 10 July 2020.
3. Brisson, Mathurin Jacques (1760). Ornithologie, ou, Méthode contenant la division des oiseaux en ordres, sections, genres, especes & leurs variétés (in French and Latin). Vol. 2. Paris: Jean-Baptiste Bauche. pp. 294–296, Plate 22 fig 3. The two stars (**) at the start of the section indicates that Brisson based his description on the examination of a specimen.
4. Allen, J.A. (1910). "Collation of Brisson's genera of birds with those of Linnaeus". Bulletin of the American Museum of Natural History. 28: 317–335. hdl:2246/678.
5. Linnaeus, Carl (1766). Systema naturae : per regna tria natura, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis (in Latin). Vol. 1, Part 1 (12th ed.). Holmiae (Stockholm): Laurentii Salvii. p. 292.
6. Gill, Frank; Donsker, David, eds. (2018). "Thrushes". World Bird List Version 8.1. International Ornithologists' Union. Retrieved 10 May 2018.

Further reading

• Bo T Bonnevie, The biology of suburban Olive Thrushes (Turdus olivaceus olivaceus) in the Eastern Cape, South Africa (2005). M.Sc. thesis, Rhodes University, South Africa
• Clement, Peter; Hathway, Ren (2000). Thrushes. Helm Identification Guides. London: A & C Black. ISBN 978-0-7136-3940-7.
• Sinclair, Hockey and Tarboton, SASOL Birds of Southern Africa, ISBN 1-86872-721-1

External links

• Olive thrush - Species text in The Atlas of Southern African Birds.