Justification of Red List category
This species is classified as Near Threatened because it is suspected to be declining moderately rapidly owing to ongoing habitat loss and degradation.
Although widespread and fairly common at a few localities, it is generally scarce and localised (Collar and Wege 1995, Parker and Willis 1997). Surveys in the Argentinian Pampas in 2006 to 2008 found the species to be rare, with records in only two of 30 transects (Codesido et al. 2012).
The global population size has not been quantified, but given the size of its range, it is assumed to be larger than 10,000 mature individuals (Collar and Wege 1995). The population in Argentina is suspected to number 2,500-10,000 mature individuals (MAyDS and Aves Argentinas 2017). In French Guiana, there are thought to be fewer than 250 mature individuals (MNHN et al. 2018).
Although there is no direct, quantitative information on population trends, the population is suspected to be in decline owing to ongoing habitat destruction and degradation.
In Colombia, habitat loss may have led the species to disappear from some areas (Ruiz-Ovalle and Chaparro-Herrera 2016), and in 2005, the species was not found at a site in Meta where it was previously recorded in the 1960s (F. G. Stiles, in Ruiz-Ovalle and Chaparro-Herrera 2016). Although an analysis of habitat change found no loss between 2001 and 2011, the species's population was suspected to have declined by more than 30% over 10.8 years due to fires and habitat conversion, with the rate of loss expected to increase in the future (Renjifo et al. 2016).
In Brazil, the population size is suspected to be declining as a result of ongoing habitat loss and degradation through conversion to agriculture and overgrazing (ICMBio 2013).
In Argentina, surveys in the pampas in 2005-2008 found that other, more common, grassland specialist bird species were present in significantly fewer counties than in 1938 to 1993 (Codesido et al. 2011). However, the species's range has expanded in La Pampa and eastern Buenos Aires since the 1980s (MAyDS and Aves Argentinas 2017).
The species's population size is suspected to be stable in the Sipaliwini Nature Reserve in south Suriname and in adjacent Brazil (O. Ottema in litt. 2020), but declining in French Guiana (MNHN et al. 2018).
Overall, the population is suspected to be declining moderately rapidly, with a rate of decline here placed in the band 10-20% over ten years, although this is highly uncertain.
Polystictus pectoralis has a localised and disjunct distribution, to the north and to the south of the Amazon basin. Subspecies bogotensis occurred in the upper río Dagua valley (Valle del Cauca), and Bogotá swamp (Cundinamarca), Colombia, but there have been no confirmed records since the 1950s and the subspecies is now considered extinct (Collar and Wege 1995, Donegan 2004, Amaya-Villarreal 2016). Subspecies brevipennis occurs in north-east Colombia (Meta, Casanare), Venezuela (from Barinas to Bolívar in the south; also Carabobo), Guyana, south Suriname (Sipaliwini), north French Guiana (Sinnamary), and extreme north Brazil (Roraima, Pará, Amapá).The nominate race occurs in central-south Brazil (Mato Grosso, Mato Grosso do Sul, Goiás, Minas Gerais, Distrito Federal, São Paulo, Paraná, Santa Catarina and Rio Grande do Sul; Parker and Willis 1997, WikiAves 2020), southern and eastern Paraguay, Uruguay, and northeast Argentina. There are several old specimens from Santa Cruz, Bolivia, but no recent records (Collar and Wege 1995). It is an austral summer visitor to central-east Argentina (south to Mendoza, La Pampa and west Buenos Aires; Collar and Wege 1995).
It inhabits a variety of grassland types, all with varying amounts of shrubby vegetation (Collar and Wege 1995, Parker and Willis 1997). It occurs in savanna with scattered shrubs, tall grass in cerrado, and low heath-like shrubs and tall grass (Fitzpatrick and Sharpe 2020). It is rarely recorded in disturbed vegetation, although several individuals have been recorded in savanna within an oil palm plantation (Ruiz-Ovalle and Chaparro-Herrera 2016). It feeds on insects (Collar and Wege 1995).
Conversion to agriculture for Eucalyptus plantations, arable agriculture (largely soybeans, maize and rice) and pastures have had a severe impact on its habitat in Brazil (Parker and Willis 1997), where two-thirds of cerrado were heavily or moderately altered by 1993 (Conservation International 1999), with most destruction having occurred since the 1950s (Cavalcanti 1999). In Rio Grande do Sul, 15.6% of native grasslands were lost over 27 years from 1976-2002 (Cordeiro and Hasenack 2009). The main ongoing cause of habitat conversion in Brazil is forestry, with developments for mining, hydroelectricity, roads, commercial premises and tourism also contributing (Urben-Filho and Costa Straube 2008, ICMBio 2013). In Argentina and Paraguay, grasslands have been converted to sown pastures for cattle ranching, and to arable agriculture (mainly soybean, sunflower, maize, wheat and rice) and tree plantations (pine and eucalyptus; Pearman and Abadie 1995, Lowen et al. 1996). Between 1985-1989 and 2002-2004, grassland cover within the Río de la Plata grassland region decreased from 67.4 to 61.4% and the area of agriculture increased from 22 to 25.9%, with declines in grassland being higher in Argentina, and some areas of flat pampas dominated by arable plantations (Baldi and Paruelo 2008). In western Uruguay, grasslands have been converted to plantations of soybean, wheat and corn (Paruelo et al. 2006). In Colombia, large areas of the Orinoco region have been converted to agriculture, and savannas have been converted to pastures and plantations of oil palm and crops, with a subsequent increase in the frequency of fires (Amaya-Villarreal 2016). The species's strict habitat requirements render it vulnerable to habitat degradation through overgrazing and fire. Conversion of land to oil palm plantations could pose a future threat (López-Ricaurte et al. 2017).
Conservation Actions Underway
The species is listed as nationally Vulnerable in Colombia (Renjifo et al. 2016) and Argentina (MAyDS and Aves Argentinas 2017), Critically Endangered in French Guyana (MNHN et al. 2018), and Near Threatened in Brazil (MMA 2014). It occurs in a number of protected areas including Canaima National Park, Venezuela; Sipaliwini Savanna Nature Reserve, Suriname; Tatí Jupí Reserve, Mbaracayú Forest Nature Reserve, Sombrero Private Reserve and San Rafael National Park, Paraguay; Otamendi Reserve, San Juan de Poriahú Private Reserve and Mburucuyá National Park, Argentina; El Tuparro National Park, Colombia; and Emas and Chapada dos Guimarães National Parks, Guartelá State Park, Ibirapuitã Environmental Protection Area and Itirapina Ecological Station, Brazil.
The species was included in the CMS MOU on the Southern South American Migratory Grassland Bird Species and their Habitats. The associated action plan (CMS 2010), which ran from 2010 to 2015, included the following actions: identification of further protected areas, management of existing protected areas for grassland birds, development of market incentives for sustainable grassland management, development of a manual of best practices for farmers, training and awareness-raising, and development of legislation for the protection of grasslands.
In Brazil, the species was included in the previous cycle of the National Action Plan for the Conservation of the Threatened Passeriformes of the Southern Grasslands and the Espinilho, which ran from 2013 to 2017 and included the following actions: creation of protected areas, improved regulation of grazing levels, promotion of sustainable agricultural practices, promotion of a certification scheme for sustainable agriculture, enforcement and improvement of environmental regulations, promotion of ecotourism, and raising awareness of conservation among local communities (ICMBio 2013).
The Southern Cone Grasslands Alliance was established in 2006 to promote sustainable ranching practices across the Southern Cone grasslands of Argentina, Brazil and Uruguay, and a certification scheme has been developed to provide a financial incentive for sustainably-produced beef (Azpiroz 2012). The species is included in a project to conserve the sources of the Uberabinha and the Mandaguari river basin in Minas Gerais, Brazil (ICMBio 2013).
Research is underway in Brazil on the species's reproductive biology (ICMBio 2013).
Conservation Actions Proposed
Survey and monitor populations to obtain a global population estimate and trend estimates. Research the species's migration patterns and habitat requirements.
Remove incentives encouraging habitat loss, especially through the planting of Eucalyptus trees on grasslands. Implement and enforce regulations to protect remaining habitat from conversion to agriculture and tree plantations. Regulate development to prevent it from having a significant impact on the species (Urben-Filho and Costa Straube 2008, ICMBio 2013). Effectively protect and manage protected areas where the species occurs. Manage agricultural land to ensure that habitat loss does not exceed habitat gain. Protect and restore areas of natural grassland. Create further protected areas to protect areas of tall grassland. Promote ecotourism and birdwatching to increase knowledge and awareness of the species (ICMBio 2013).
Text account compilers
Ottema, O., Capper, D., Clay, R.P., Isherwood, I., O'Brien, A., Sharpe, C.J., Symes, A. & Khwaja, N.
BirdLife International (2023) Species factsheet: Polystictus pectoralis. Downloaded from http://datazone.birdlife.org/species/factsheet/bearded-tachuri-polystictus-pectoralis on 05/12/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 05/12/2023.