Sharp-tailed tyrant (Culicivora caudacuta)

Also known as: Sharp-tailed grass tyrant
GenusCulicivora (1)
SizeLength: 11 cm (2)

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

The sharp-tailed tyrant is a small, grassland flycatcher (3), named for the pointed feathers of its long, brown, slender tail (4). The head is black, with a contrasting broad, white stripe above each eye, while the body has dark brown upperparts (2), yellowy-white underparts and cinnamon-buff patches on the sides (4). Although not a very vocal bird, it may call with a rather weak and nasally ‘ree, ree’  (2) (5). It is also commonly referred to as the sharp-tailed grass tyrant due to its typical grassland range (4).

This rare bird is restricted to the grasslands of central South America (4), occurring in Bolivia, Brazil, Paraguay, Uruguay and Argentina (2).

The sharp-tailed tyrant primarily inhabits subtropical, tall, dry grasslands (4), but can also be found in shorter, wetter areas (2).

Although typically found individually or in pairs (4), the sharp-tailed tyrant has also been reported in small groups of three to seven birds (6). It may be seen moving through the long grass and perching in low bushes as it searches for insects, on which it primarily feeds (4). It has also been noted to occasionally feed on the seeds of grass and other flowering plants, which no other tyrant species is known to do (4).

Although information on the sharp-tailed tyrant’s breeding biology is scarce, it apparently breeds between October and March (2).  A cup-shaped nest has been found containing three yellowish-beige coloured eggs (3).

The sharp-tailed tyrant’s population is thought to be rapidly decreasing due to several threats, including ongoing habitat degradation and destruction (2). This continual degradation is predominantly due to overgrazing, particularly caused by excessive cattle ranching (4), the conversion of land to soybean and Eucalyptus plantations, and the frequent occurrence of fires (2). As a result, not many sharp-tailed tryants now survive outside the few nature and biological reserves in the area (3).

At present, the sharp-tailed tyrant is protected by law in Paraguay and current studies are being carried out on threatened grassland species at the Reserva Isla Yacyreta in Paraguay (2). Unsurprisingly, populations of the sharp-tailed tyrant appear to be highest where human activities are either controlled or prevented, such as in Brasilia and Emas Nature Parks, Brazil (4), emphasizing the importance of increasing the area of suitable habitat that is protected (2). Further studies on the sharp-tailed tyrant’s ecology and surveys to assess its population size have also been proposed, in order to inform future conservation efforts for this species (2).

To learn more about the sharp-tailed tyrant and bird conservation in general see:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:

  1. IUCN Red List (May, 2010)
  2. BirdLife International (May, 2010)
  3. Parker III, T.A. and Willis, E.O (1997) Notes on three tiny grassland flycatchers, with comments on the disappearance of South American fire-diversified savannas. Ornithological Monographs, 48: 549-555.
  4. Ridgely, R.S. and Tudor, G. (1994) The Birds of South America: The Suboscine Passerines. University of Texas Press, Austin, Texas.
  5. Ridgely, R.S. and Tudor, G. (2009) Field Guide to the Songbirds of South America. The Passerines. University of Texas Press, Austin, Texas. 
  6. Silveira, L.F. (1998) The birds of Serra da Canastra National Park and adjacent areas, Minas Gerais, Brazil. Cotinga, 10: 55-63.