Grey-bellied shrike-tyrant  (Agriornis micropterus)

Classified as Least Concern (LC) on the IUCN Red List (1).

The grey-bellied shrike-tyrant was discovered in Patagonia by the eminent naturalist Charles Darwin (3). This species has mostly brownish-grey upperparts, with a whitish band running above the eye, and a blackish-brown tail. The throat is whitish with heavy streaking, which is black in the male and dark brown in the female. The breast is pale grey-brown to whitish, becoming browner towards the flanks. Perhaps the most distinctive feature of the grey-bellied shrike-tyrant is the robust, long bill, the upper part of which has a markedly hooked tip and is dark brown, while the lower part is orange. There are two subspecies of grey-bellied shrike-tyrant, Agriornis micropterus micropterus and Agriornis micropterus andecola, the latter being slightly larger and darker (2).

Subspecies Agriornis micropterus micropterus has the largest range, occupying much of central and southern Argentina, while Agriornis micropterus andecola can be found further north in southern Peru, Bolivia, northern Chile and north-west Argentina (2).

The grey-bellied shrike-tyrant is generally found in lowland and montane open grassland with scattered shrubs and boulders, but may also be found in agricultural areas during the austral winter. In the southern part of its range, this species can be found from sea-level to elevations of 5,000 metres, whereas in the northern part, it is most commonly found between elevations of 2,000 and 4,000 metres (2)

A solitary species, the grey-bellied shrike-tyrant is commonly found perching conspicuously on the top of a rock or bush (2) (3). This species is a skilled hunter, taking insects on the wing or catching its prey whilst running along the ground. Other prey sources include small mammals, lizards, frogs and the eggs and nestlings of other bird species (2).

In order to attract a mate, the male grey-bellied shrike-tyrant gives an aerial display, during which the two short, outer primary feathers produce a low-pitched, barely audible whirring sound. Although many aspects of the grey-bellied shrike-tyrant’s reproduction are currently unknown, eggs have been found in January in Chile, while in Argentina, nests have been recorded in September and October, and eggs and fledglings reported in December (2).

While the subspecies Agriornis micropterus andecola remains in the same location throughout the year, Agriornis micropterus micropterus leaves its breeding grounds in February, migrating northwards to southern Bolivia, Paraguay and northern Argentina where it overwinters (2).

Although generally uncommon, the grey-bellied shrike-tyrant has a large range and is not considered to be threatened (2) (4).

While there are currently no known conservation measures in place for the grey-bellied shrike-tyrant (4), it is found in a number of protected areas throughout its range (5).

To learn more about conservation initiatives within the grey-bellied shrike-tyrant’s range visit:

• WWF:
  www.panda.org/who_we_are/wwf_offices/argentina

• Subspecies: a population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.

1. IUCN Red List (December, 2008)
   http://www.iucnredlist.org
2. del Hoyo, J., Elliott, A. and Sargatal, J. (1992) Handbook of the Birds of the World. Volume 9: Cotingas To Pipits And Wagtails.Lynx Edicions, Barcelona.
3. Gould, J. and Darwin, C.R. (1839) Birds: Part 3, No. 4 of The zoology of the voyage of H.M.S. Beagle. by John Gould. Edited and superintended by Charles Darwin.Smith Elder and Co, London. Available at: http://darwin-online.org.uk
4. BirdLife International (April, 2009)
   http://www.birdlife.org
5. World Database on Protected Areas (April, 2009)
   http://www.wdpa.org