White-tailed shrike-tyrant  (Agriornis albicauda)

Classified as Vulnerable (VU) on the IUCN Red List (1).

The white-tailed shrike-tyrant (Agriornis albicauda) has dark grey central tail feathers, but the contrasting outlying feathers are bright white, giving the white-tailed shrike-tyrant its name. The back of the white-tailed shrike-tyrant is dark grey and the wings have a pale margin and buff undersides. The throat is white with dark streaks while the upper breast and sides of the white-tailed shrike-tyrant are grey-brown. The lower breast, belly, and rear are off-white, but may occasionally have a buff tinge (2).

A narrow buff coloured stripe runs from the base of the beak to above the eye, becoming streaked at the side of the head. The white-tailed shrike-tyrant has a hooked bill, which is large and powerful for the size of the bird. The beak is dark on top and cream to yellowish below and the legs are dark, varying to black (2).

There is little difference in appearance between male and female white-tailed shrike-tyrants (2) and the call is loud and melodic with many variations around “teeu, tcheeu-tcheeu-tcheeuw!” (2).

The white-tailed shrike-tyrant can be found in the high Andes, from Ecuador to northern Chile and Argentina. There are two white-tailed shrike-tyrant subspecies: Agriornis albicauda andicola from Ecuador and Agriornis albicauda albicauda from Peru, western Bolivia, northern Chile and north-western Argentina (3).

The habitat of the white-tailed shrike-tyrant is typically semi-arid scrubland between 2,400 and 4,300 metres above sea level (3). It prefers open, rocky, sparsely vegetated habitat, and can also be found near buildings and walls. In Ecuador, the white-tailed shrike-tyrant has been infrequently observed in open farmland with Eucalyptus trees (3).

The white-tailed shrike-tyrant will perch on rocks and in trees with views of the surrounding habitats. From these lookouts, the white-tailed shrike-tyrant hunts large insects, small mammals, lizards, frogs and the eggs or nestlings of other birds (2). 

The white-tailed shrike-tyrant builds its nest on the ground, in the shelter of sparse vegetation. The nest is built on a base of twigs from dry grass stems and moss, and is lined with feathers and other materials such as; horse hair, plant matter and snake skin. The nest is usually about 50 centimetres across, while inside it measures around 11 centimetres across and 7 centimetres deep (4).

The display flight of the male white-tailed shrike-tyrant consists of circling at height, repeatedly pulling its wings in and dropping down forwards before pulling back up (4).

The white-tailed shrike-tyrant appears to have declined in recent decades and populations are becoming increasingly fragmented (3). The full reasons for this decline have not been well researched, though it seems that habitat change, such as clearing of scrub plants including Puya raimondii by sheep farmers, may disrupt nesting patterns (5). The white-tailed shrike-tyrant has, however, been recorded breeding in cattle pasture where scrub, pine trees and Eucalyptus are present (6). 

The white-tailed shrike-tyrant has recently been recorded in four national reserves and a conservation area in Argentina. The recommended conservation actions for the white-tailed shrike-tyrant include monitoring of known populations, and surveys to find new populations (3).

Further study to discover more about the ecology of the white-tailed shrike-tyrant and the threats affecting it are also recommended (3).

Find out more about this and other bird species:

• BirdLife International (white-tailed shrike-tyrant):
  http://www.birdlife.org/datazone/speciesfactsheet.php?id=4323#FurtherInfo