Family Typical Antbirds (Thamnophilidae)

Critically Endangered

Marsh Antwren (Formicivora paludicola)


French: Grisin de Sao Paulo German: Sumpfameisenfänger Spanish: Hormiguerito paludícola
Other common names: Sao Paulo Marsh Antwren

Formicivora paludicola

Buzzetti et al.

, 2013,

Córrego Taboão do Parateí (23°24’27” S, 46°13’35” W; 630 m asl), Mogi das Cruzes, São Paulo, Brazil


Perhaps only a race#R and evidently weakly differentiated in voice from F. acutirostris, but detailed molecular analyses#R indicate that paludicola and acutirostris represent distinct clades and reciprocally monophyletic groups. Further, (from published data#R) differs in its black vs dark grey underparts in male (2); dark greyish-brown vs dark brown upperparts in male (1); shorter bill (effect size for female –5.75, score 3); wider bill (effect size for female 0.83, score 1). Monotypic.

What do (1) and (2) mean? Learn more about the scoring system.

SE Brazil in E São Paulo (headwaters of the R Tietê and R Paraíba do Sul Basins)#R.

Descriptive notes

14·7 cm; male 8·5–11 g, female 8–9·6 g. Male has crown, mantle and uppertail-coverts dark greyish brown, with grey forehead, black lores black and white supercilium; ear-... read more


Very similar to that of F. acutirostris. Mainly vocal early morning and late afternoon,... read more


Confined to marshes dominated by cattails (Typha domingensis; Typhaceae) and bulrushes (... read more

Food and feeding

Diet is very poorly known, but apparently is largely or exclusively insects such as mosquitos, mantises and caterpillars. Generally occurs... read more


Virtually nothing known, but nesting biology presumably very similar to that of F. acutirostris. Season Oct–Feb: both sexes have... read more


Resident, with probably low dispersal capabilities, although genetic evidence suggests that some... read more

Status and conservation

CRITICALLY ENDANGERED. Discovered in Oct 2004, in remarkably close proximity to the huge urban metropolis of São Paulo, and apparently already on the brink of extinction.... read more