Justification of Red List Category
This species is classified as Vulnerable because the extent of habitat modification within its range indicates that it is undergoing a rapid population reduction. Threats appear to be increasing, and the rapid growth of the forestry industry in Argentina is particularly concerning.
The population size is preliminarily estimated to fall into the band 10,000-19,999 individuals. This equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals.
This species's population is suspected to be declining rapidly, in line with rates of habitat loss within its range.
Xolmis dominicanus occurs in Brazil (São Paulo, Paraná, Santa Catarina and Rio Grande do Sul), Uruguay (recently from Paysandú, Canelones, Lavalleja, Maldonado, Rocha, Treinta y Tres and Cerro Largo [A. B. Azpiroz in litt. 2000, Codesido and Fraga 2009]), Argentina (recently from Corrientes, Entre Ríos and Buenos Aires [Fraga 2003, Codesido and Fraga 2009) and there are unconfirmed reports for Paraguay (Contreras 1995). It has undergone a catastrophic decline since c.1850. The current stronghold is possibly south-east Uruguay, where the population is estimated at 1,500-2,200 breeding birds, mostly in Rocha (A. B. Azpiroz in litt. 2000). In Brazil, it remains numerous only in south-east Santa Catarina, and north-east and south-east Rio Grande do Sul. It has declined notably in Argentina, especially in Buenos Aires, where it was previously common (Narosky and DiGiacomo 1993), and most records are now in Corrientes and Entre Ríos (Pearman and Abadie 1995, Fraga 2003, Codesido and Fraga 2009). Although populations may still persist in southern Misiones, there are no recent reliable records from Santa Fe, Chaco or Formosa (Fraga 2003).
It inhabits scrubby grasslands, especially near marshes. In Entre Ríos and Corrientes, it has occurred in old paddy-fields that were unused for over five years (Pearman and Abadie 1995), and it occasionally visits cultivations with Saffron-cowled Blackbird Xanthopsar flavus. In Corrientes, it is relatively common in recently burnt areas (J. C. Chebez in litt. 1999). Nests have been found in vegetation within boggy swales (Suertegaray Fontana 1997, A. B. Azpiroz in litt. 2000). Breeding activity in Argentina has been noted during September-December (Fraga 2003).
Agriculture, and especially livestock-grazing, has modified grasslands since the 16th century, and intensely since the 1870s (Bucher and Nores 1988). Very recently, afforestation with non-native trees has begun to radically alter remaining grasslands, especially in Entre Ríos and Corrientes (Pearman and Abadie 1995). Anthropogenic fires have destroyed nests (A. B. Azpiroz in litt. 2000). In Uruguay, one study has shown very high levels of brood-parasitism by Shiny Cowbird Molothrus bonariensis (A. B. Azpiroz in litt. 2000).
Conservation Actions Underway
In Argentina, it has been recorded in Chaco, Mburucuyá and El Palmar National Parks, San Juan Poriahú and Campos del Tuyú Private Reserves and Ribera Norte Municipal Reserve (Chebez et al. 1998), but only a few of these protected areas support significant breeding populations (Fraga 2003). In Brazil, it is known from Aparados da Serra and São Joaquim National Parks, the general area of Serra Geral National Park (Parker and Goerck 1997, Bencke and Kindel 1999), and Taim Ecological Station (Mahler et al. 1996). In Uruguay, it is legally protected, and resident in Bañados del Este Biosphere Reserve and Laguna de Castillos, Potrerillo de Santa Teresa and Los Indios Reserves (A. B. Azpiroz in litt. 2000).
20.5 cm. Striking, piebald tyrant-flycatcher. Male white, with contrasting black wings and tail. White wing-tips especially visible in flight. Female similar, with brownish-grey crown, hindneck and centre of back. Similar spp. White Monjita Xolmis irupero is smaller, with black-tipped white tail and much less black on wings. Voice Mostly silent. Occasionally delivers soft calls.
Text account compilers
Capper, D., Harding, M., Mazar Barnett, J., Pople, R., Sharpe, C J, Symes, A., Williams, R.
Olmos, F., Laesser, J., del Castillo, H., Chebez, J., Azpiroz, A., Fraga, R.
BirdLife International (2017) Species factsheet: Xolmis dominicanus. Downloaded from http://www.birdlife.org on 17/10/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 17/10/2017.