2 thoughts on “Black-and-white Monjita (Xolmis dominicanus)”
This grassland specialist lives primarily in native grasslands interspersed with boggy swales and depressions. Within this landscape, it uses the bogs for nesting and roosting but forages mainly in the surrounding drier grasslands, which provide sparse shrubs, rocks, or other low perches for hunting invertebrates. Although it may occasionally use croplands, these are typically small patches embedded within a native grassland matrix. The species’ sensitivity to habitat alteration, particularly grassland loss and fragmentation, underlies its previous classification as threatened.
The proposal to downlist the species from Vulnerable to Near Threatened relies on the assumption that habitat loss across its range does not meet the threshold for a higher threat category. The relevance of the 30% grassland loss documented in Brazil during the first two decades of the 21st century is questioned, with the argument that it may not reflect current conditions or be representative of the species’ entire range. Occasional records in forest edges and agricultural areas are interpreted as signs of broader habitat tolerance. However, this view oversimplifies the species’ ecological requirements and underestimates the concentration of threats in areas that support the largest and most viable subpopulations. Although some individuals may forage in croplands or along forest margins, such use is marginal and typically restricted to areas adjacent to native grasslands. There is no evidence that the species can persist in intensively managed monocultures, forest plantations, or natural forests, which are unlikely to support viable populations.
A particularly problematic aspect of the proposal is the claim that populations may use forested habitats. In practice, individuals in such contexts occupy grassland-forest ecotones and rely exclusively on the grassland component. Likewise, the suggestion that agricultural areas provide alternative habitat overlooks the rapid conversion of native grasslands into industrial row crops and exotic tree plantations, land-use changes that are fundamentally incompatible with the species’ ecological requirements.
Data from eBird and WikiAves suggest the existence of at least eight major subpopulations: (1) Campos Gerais (Paraná), (2) Campos de Palmas and Água Doce (Paraná and Santa Catarina), (3) Planalto das Araucárias and Planalto São Joaquim–Lages (southeastern Santa Catarina and northeastern Rio Grande do Sul), (4) Banhado do Maçarico region (southern coastal Rio Grande do Sul), (5) a broad area from southeastern Rio Grande do Sul into eastern and southern Uruguay, (6) southern Entre Ríos and adjacent southwestern Uruguay, (7) Corrientes and neighboring areas in Paraguay, and (8) coastal Buenos Aires. The largest areas of occurrence, though not necessarily supporting the largest populations, given unknown and likely variable densities, are the Planalto das Araucárias–São Joaquim–Lages, southeastern Rio Grande do Sul into southern Uruguay, and Corrientes. Some individuals undertake seasonal movements, but migratory patterns remain poorly understood, and records outside these core areas may reflect either dispersing individuals or small, local populations. Thus, the range mapped in this proposal is exaggerated, as the species is absent or occurs only locally in central and western Uruguay and western Rio Grande do Sul.
The claim that populations in Corrientes are largely protected also deserves closer examination. Although the Iberá reserve is a major conservation area, it primarily safeguards marshes rather than the open grasslands with linear bogs that the species requires. Most breeding individuals occur outside formally protected areas, in grasslands east and west of the Iberá wetlands that are increasingly threatened by pine and eucalyptus plantations, pine invasion, and extensive fires exacerbated by droughts linked to climate change. While recent satellite imagery suggests that grassland cover in Corrientes has remained relatively stable over the past decade, ongoing threats and the absence of effective protection for grassland-dependent species remain significant concerns.
In Brazil, grassland loss was particularly severe until 2018 and affected key strongholds. Over the past decade, however, it has stabilized in most regions, with the notable exception of southwestern Rio Grande do Sul. In the southeastern Planalto of Santa Catarina, grasslands declined from 258,000 to 246,000 ha, a 4.65% reduction from 2015 to 2024. In the northeastern Planalto das Araucárias of Rio Grande do Sul, the decline was from 495,000 to 474,000 ha (4.24%). In southwestern Rio Grande do Sul, however, the loss was more substantial, from 900,000 to 775,000 ha, a 14% reduction in this same period. It remains unclear how the 30% loss that occurred up to 2018 has impacted Brazilian populations, and stabilization in recent years does not necessarily imply recovery, as population responses may lag behind habitat changes. In Uruguay, grassland loss has also slowed, but threats such as row crop and tree plantation expansion, pine tree invasion and wind farm development may be locally significant. The latter two issues are now affecting the Banhado do Maçarico region, another important stronghold and where grasslands were historically preserved from large-scale conversion.
A past decline of 20–29% over three generations appears reasonable, and there is likely no evidence of a 30% reduction across most of the range, including Brazil, in the past three generations/11 years. I also consider the estimated population size of 11,000–20,000 individuals plausible. However, the reported Extent of Occurrence of 910,000 km² is inflated, as a comparison between the assessment map and occurrence data from eBird and WikiAves makes evident. Given the smaller actual extent, the species’ naturally fragmented distribution, its inability to persist in industrial row crops, forest plantations, or natural forests, and the ongoing threats combined with unknown demographic effects of rapid habitat loss over the past 30 years, I find the justification for downlisting this species to Near Threatened insufficient.
Dias, R. A. (2018). Xolmis dominicanus (Vieillot, 1823). In Livro Vermelho da Fauna Brasileira Ameaçada de Extinção: Volume III – Aves (pp. 548–551). Brasília, DF: ICMBio/MMA.
This grassland specialist lives primarily in native grasslands interspersed with boggy swales and depressions. Within this landscape, it uses the bogs for nesting and roosting but forages mainly in the surrounding drier grasslands, which provide sparse shrubs, rocks, or other low perches for hunting invertebrates. Although it may occasionally use croplands, these are typically small patches embedded within a native grassland matrix. The species’ sensitivity to habitat alteration, particularly grassland loss and fragmentation, underlies its previous classification as threatened.
The proposal to downlist the species from Vulnerable to Near Threatened relies on the assumption that habitat loss across its range does not meet the threshold for a higher threat category. The relevance of the 30% grassland loss documented in Brazil during the first two decades of the 21st century is questioned, with the argument that it may not reflect current conditions or be representative of the species’ entire range. Occasional records in forest edges and agricultural areas are interpreted as signs of broader habitat tolerance. However, this view oversimplifies the species’ ecological requirements and underestimates the concentration of threats in areas that support the largest and most viable subpopulations. Although some individuals may forage in croplands or along forest margins, such use is marginal and typically restricted to areas adjacent to native grasslands. There is no evidence that the species can persist in intensively managed monocultures, forest plantations, or natural forests, which are unlikely to support viable populations.
A particularly problematic aspect of the proposal is the claim that populations may use forested habitats. In practice, individuals in such contexts occupy grassland-forest ecotones and rely exclusively on the grassland component. Likewise, the suggestion that agricultural areas provide alternative habitat overlooks the rapid conversion of native grasslands into industrial row crops and exotic tree plantations, land-use changes that are fundamentally incompatible with the species’ ecological requirements.
Data from eBird and WikiAves suggest the existence of at least eight major subpopulations: (1) Campos Gerais (Paraná), (2) Campos de Palmas and Água Doce (Paraná and Santa Catarina), (3) Planalto das Araucárias and Planalto São Joaquim–Lages (southeastern Santa Catarina and northeastern Rio Grande do Sul), (4) Banhado do Maçarico region (southern coastal Rio Grande do Sul), (5) a broad area from southeastern Rio Grande do Sul into eastern and southern Uruguay, (6) southern Entre Ríos and adjacent southwestern Uruguay, (7) Corrientes and neighboring areas in Paraguay, and (8) coastal Buenos Aires. The largest areas of occurrence, though not necessarily supporting the largest populations, given unknown and likely variable densities, are the Planalto das Araucárias–São Joaquim–Lages, southeastern Rio Grande do Sul into southern Uruguay, and Corrientes. Some individuals undertake seasonal movements, but migratory patterns remain poorly understood, and records outside these core areas may reflect either dispersing individuals or small, local populations. Thus, the range mapped in this proposal is exaggerated, as the species is absent or occurs only locally in central and western Uruguay and western Rio Grande do Sul.
The claim that populations in Corrientes are largely protected also deserves closer examination. Although the Iberá reserve is a major conservation area, it primarily safeguards marshes rather than the open grasslands with linear bogs that the species requires. Most breeding individuals occur outside formally protected areas, in grasslands east and west of the Iberá wetlands that are increasingly threatened by pine and eucalyptus plantations, pine invasion, and extensive fires exacerbated by droughts linked to climate change. While recent satellite imagery suggests that grassland cover in Corrientes has remained relatively stable over the past decade, ongoing threats and the absence of effective protection for grassland-dependent species remain significant concerns.
In Brazil, grassland loss was particularly severe until 2018 and affected key strongholds. Over the past decade, however, it has stabilized in most regions, with the notable exception of southwestern Rio Grande do Sul. In the southeastern Planalto of Santa Catarina, grasslands declined from 258,000 to 246,000 ha, a 4.65% reduction from 2015 to 2024. In the northeastern Planalto das Araucárias of Rio Grande do Sul, the decline was from 495,000 to 474,000 ha (4.24%). In southwestern Rio Grande do Sul, however, the loss was more substantial, from 900,000 to 775,000 ha, a 14% reduction in this same period. It remains unclear how the 30% loss that occurred up to 2018 has impacted Brazilian populations, and stabilization in recent years does not necessarily imply recovery, as population responses may lag behind habitat changes. In Uruguay, grassland loss has also slowed, but threats such as row crop and tree plantation expansion, pine tree invasion and wind farm development may be locally significant. The latter two issues are now affecting the Banhado do Maçarico region, another important stronghold and where grasslands were historically preserved from large-scale conversion.
A past decline of 20–29% over three generations appears reasonable, and there is likely no evidence of a 30% reduction across most of the range, including Brazil, in the past three generations/11 years. I also consider the estimated population size of 11,000–20,000 individuals plausible. However, the reported Extent of Occurrence of 910,000 km² is inflated, as a comparison between the assessment map and occurrence data from eBird and WikiAves makes evident. Given the smaller actual extent, the species’ naturally fragmented distribution, its inability to persist in industrial row crops, forest plantations, or natural forests, and the ongoing threats combined with unknown demographic effects of rapid habitat loss over the past 30 years, I find the justification for downlisting this species to Near Threatened insufficient.
References
Dias, R. A. (2018). Xolmis dominicanus (Vieillot, 1823). In Livro Vermelho da Fauna Brasileira Ameaçada de Extinção: Volume III – Aves (pp. 548–551). Brasília, DF: ICMBio/MMA.
MapBiomas Pampa Platform. (2025). Retrieved from https://plataforma.pampa.mapbiomas.org/
MapBiomas Brasil Platform. (2025). Retrieved from https://plataforma.brasil.mapbiomas.org/cobertura?activeBaseMap=9&layersOpacity=100&activeModule=coverage&activeModuleContent=coverage%3Acoverage_main