Data Zone
Justification of Red List category
Extensive and continuing habitat loss throughout the range of this species has presumably resulted in rapid population declines. It consequently qualifies as Vulnerable.
Population justification
The population is estimated to number 10,000-19,999 individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size (e.g. the lower end of such estimates is 1 / km2) and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. A much higher density of 6.7 individuals / km2 was found in Itirapina Ecological Station, São Paulo, Brazil (Kanegae 2012).
Trend justification
This species's population size is suspected to be declining rapidly in line with rates of habitat loss within its range.
Alectrurus tricolor has become very scarce and local over a large range in north and east Bolivia, occurring in a few scattered localities in La Paz and Santa Cruz (Parker et al. 1991, Ridgely and Tudor 1994, Brace et al. 1997) and frequently in the pampas of north and west Beni (Parker et al. 1991, Ridgely and Tudor 1994, Brace et al. 1997, M. Herrera in litt. 2007), but being inexplicably absent from large areas (Parker et al. 1991, Brace et al. 1997); central and southern Brazil (R. E. Fernandes Santos in litt. 2011), in Mato Grosso, Mato Grosso do Sul, Goiás, Distrito Federal, Minas Gerais and Espírito Santo south to Paraná, where there are few records (Santos 2007, R. E. Fernandes Santos in litt. 2011), and possibly Rio Grande do Sul (Ridgely and Tudor 1994, Machado et al. 1998, L. F. Silveira in litt. 2000); east Paraguay, in Concepción, San Pedro (Robbins et al. 1999, M. B. Robbins in litt. 2000, H. del Castillo in litt. 2007), Cordillera (Lowen et al. 1996), Caazapá (Clay et al. 1998), Itapúa (M. Velázquez in litt. 2000, H. del Castillo in litt. 2007, Codesido and Fraga 2009) and Misiones (H. del Castillo in litt. 2007, Codesido and Fraga 2009), and north Argentina, where a few old specimens were taken in north-east Corrientes and south Misiones (Ridgely and Tudor 1994), but the species has not been recorded since September 1979, despite searches in suitable habitat (Pearman and Abadie 1995, Azpiroz et al. 2012). In Brazil it remains locally common only in a few scattered protected areas in Goiás, Distrito Federal and Minas Gerais (Machado et al. 1998), while in Paraguay it is generally very rare (R. Clay in litt. 2011), but locally common and apparently a stable breeding resident at Estancia Laguna Blanca in San Pedro; Estancia La Graciela in Misiones, and Kanguery in San Rafael National Park, Itapúa (H. del Castillo in litt. 2007).
It inhabits seasonally wet and dry grasslands, known as campo limpo and campo sujo respectively (Parker et al. 1991, Machado et al. 1998, Silveira 1998), favouring areas of taller vegetation (30-100 cm) and, in Bolivia, especially areas of Trachypogon (Parker et al. 1991). In southern Brazil, the species has been recorded in humid grassland dominated by Cyperaceae, as well as Poaceae, species (R. E. Fernandes Santos in litt. 2011). Although it normally disappears from burnt sites (Cavalcanti 1988), it has been observed feeding on the ground in recently burnt areas (Lowen et al. 1996). It is generally insectivorous, though a female has been observed feeding small fruit to two fledglings. In Serra da Canastra it is migratory, arriving between mid-August and September and departing in December and January (Silveira 1998), but it appears to be resident at several sites in Paraguay (H. del Castillo in litt. 2007). Breeding occurs at the start of the wet season in September and October (Parker et al. 1991, M. B. Robbins in litt. 2000). In southern Brazil, it has been recorded nesting on the ground in a very wet area of grassland (R. E. Fernandes Santos in litt. 2011). Despite reports, does not appear to be migratory; may be partially migratory, or exhibit seasonal changes in social behaviour, or nomadism (Marini et al. 2013). Long-term year-round population studies are required in order to elucidate this (Marini et al. 2013).
Grassland habitats throughout its range are threatened by agricultural development, livestock-farming, plantations and mining (Machado et al. 1998, R. Clay in litt. 2011). Its dependence on tall grasslands make it especially sensitive to intensive grazing, trampling by cattle and frequent burning (Parker et al. 1991, R. Clay in litt. 2011). Afforestation with Eucalyptus, cattle ranching and the introduction of invasive jaragua grasses are key threats to the population at Cerrado Laguna Blanca, Paraguay, where a recently instated reserve has failed to protect the species (H. del Castillo in litt. 2012). Uncontrolled burning and the introduction of exotic grasses are major threats elsewhere in the country (H. del Castillo in litt. 2007, R. Clay in litt. 2011). The conversion of grassland to soy plantations is an on-going threat in Brazil at least (R. E. Fernandes Santos in litt. 2011). In Paraná, Brazil, habitat loss and modification are severe, driven largely by conversion to pine plantations (R. E. Fernandes Santos in litt. 2011). The recently instated Reserva Natural Privada Laguna Blanca in Paraguay, within the IBA Cerrado de Laguna Blanca, failed to protect the species, which is threatened with the continuous conversion of natural grasslands into pastures with exotic African grass and Eucalyptus plantation inside the IBA. It is predicted to lose 30–46 % of its year-round range by 2100 because of an expected range shift due to climate change (Marini et al. 2009).
Conservation Actions Underway
In Brazil, it is locally common in Emas National Park in Goiás (Machado et al. 1998, R. E. Fernandes Santos in litt. 2011), Gama-Cabeça de Veado Environmental Protection Area, Brasília National Park in Distrito Federal, Serra da Canastra National Park and São Miguel Wildlife Sanctuary in Minas Gerais (Machado et al. 1998). In Paraguay it is protected by law, and occurs in San Rafael National Park (where Guyra Paraguay protects the site at Kanguery), Serranía San Luis National Park, Tapytá Private Nature Reserve (Clay et al. 1998), Morombi Private Reserve and on a protected private estancia at La Graciela (H. del Castillo in litt. 2012). In 2008, Asociación Armonía, with the support of the American Bird Conservancy and World Land Trust-U.S., created the Barba Azul Nature Reserve in Beni Province, Bolivia, protecting habitat occupied by the species in the Beni savanna (BirdLife International 2008). A tiny population in Jaguariaíva County, Paraná state, where the species is rare, was monitored in 2007-2008, and will be searched for in the future (R. E. Fernandes Santos in litt. 2011).
12 cm (male 18 cm including tail). Striking tyrant-flycatcher. Male mostly black above, with grey rump and white shoulder patch. White face and underparts. Black patch on breast sides. Black tail with broad central rectrices, elongated and orientated perpendicular to other rectrices. Female similar to male, but brown instead of black. Whitish below, tinged buff. Normal-shaped, short tail. Similar spp. Both sexes of Strange-tailed Tyrant A. risora have complete breast-band and elongated outer rectrices. Voice Mostly silent, but some inconspicuous calls.
Text account compilers
Khwaja, N., Sharpe, C J, Taylor, J., Clay, R.P., Capper, D., Symes, A., Pople, R., Williams, R.
Contributors
del Castillo, H., Clay, R.P., Silveira, L., Herrera, M., Robbins, M., Velásquez, M., Fernandes Santos, R.
Recommended citation
BirdLife International (2024) Species factsheet: Cock-tailed Tyrant Alectrurus tricolor. Downloaded from
https://datazone.birdlife.org/species/factsheet/cock-tailed-tyrant-alectrurus-tricolor on 25/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 25/12/2024.