Justification of Red List Category
This species is classified as Near Threatened because it is suspected to have a moderately small population which is inferred to be declining owing to habitat loss and degradation in parts of its range.
It is described as rare to locally common (Bostwick 2020). It is more or less common in Córdoba, where the major global stronghold is protected by the Bañados del Río Dulce and Laguna de Mar Chiquita Natural Park, and frequent in Santiago del Estero. The population size has not been estimated directly, but is suspected to number at least 10,000 individuals (BirdLife International 2012), which roughly equates to 6,700 mature individuals. The population size is here placed in the band 6,700 - 19,999 mature individuals. The subpopulation structure is not known, but the species is highly mobile and so it is assumed to function as a single subpopulation.
The population is inferred to be in decline owing to ongoing habitat destruction for agricultural conversion.
Pseudocolopteryx dinelliana breeds in north Argentina (Santiago del Estero, Santa Fe, Chaco, Córdoba, San Juan, western Buenos Aires, Tucumán, and Salta) and winters in northern Argentina, southern Bolivia, Paraguay, and extreme southwest Brazil (Mato Grosso do Sul; Pérez-Villamayor et al. 2014).
It inhabits periodically flooded rushy and grassy marsh vegetation and shrubbery near watercourses in lowland scrub, with nests found in bushes, rushes and tall grass. Outside the breeding season, it occurs in humid chaco and pantanal habitats (Smith et al. 2014). It feeds on arthropods. It is migratory, moving north from April to October (Smith et al. 2014).
Canalisation may affect the wetlands of Bañados del Río Dulce and Laguna de Mar Chiquita (J. C. Chebez in litt. 1995, 1999), and there are other modifications to wetlands occurring within its range (Hayes et al. 1994). Where it inhabits drier savanna-type vegetation, it is under some pressure from agricultural conversion, particularly for cattle ranching. In Paraguay, habitat at the Bahía de Asunción Ecological Reserve has been lost since 2010 due to road construction (Smith et al. 2014).
Conservation Actions Underway
The stronghold is Bañados del Río Dulce and Laguna de Mar Chiquita Natural Park (Argentina). In the non-breeding season it occurs in San Antonio Private Nature Reserve, Bahía de Asunción Ecological Reserve, and Tacuara National Park, Paraguay, and in Maracajú/Mbaracayú Biological Refuge, on the Brazil - Paraguay border.
11.5 cm. Small, pale yellow and brown flycatcher. Upperparts pale olivaceous brown, with plainer brown crown. Underparts yellow, brighter on throat. Faint buffy wing-bars. Similar spp. Most similar to Warbling Doradito P. flaviventris which is browner above with a more rufescent crown; often shows a squared-off head shape, well rounded in Dinelli's. Voice A series of soft, high pitched chattered and fast rolling notes chrrret-chrrret chrrrut ended up in a very thin íík. Hints Generally conspicuous and tame in their shrubby habitat, but not always easy to locate.
Text account compilers
Chebez, J.C., Sharpe, C.J., Symes, A., Mazar Barnett, J., O'Brien, A. & Capper, D.
BirdLife International (2022) Species factsheet: Pseudocolopteryx dinelliana. Downloaded from http://www.birdlife.org on 04/10/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 04/10/2022.