Ornithologists Discover New Bird Species in Brazil
A previously unrecognized species of the antthrush genus Chamaeza has been discovered in the isolated highland rainforests of northeastern Brazil.
“Chamaeza comprises ground-dwelling suboscine birds specialized for life in the understory of Neotropical forests,” said Universidade Estadual Paulista ornithologist Vagner Cavarzere and his colleagues.
“These secretive birds occupy forest floors from lowland to mid-elevation montane habitats, where they forage primarily in leaf litter and among fallen logs for arthropods.”
“Although they occasionally follow army ant swarms, this behavior occurs less frequently than in other ant-following birds.”
“Chamaeza species exhibit cryptic plumage adapted for leaf-litter camouflage, with no apparent sexual dimorphism.”
“Their reproductive strategy involves nesting in natural cavities of decaying logs, with biparental care extending through the nestling and fledgling stages.”
“Ecologically, they are solitary foragers with limited dispersal capacity, reflecting their specialization for stable forest interiors.”
“The genus consists of six species with distinct biogeographic distributions across South America’s forested regions.”
In their new study, the authors found that populations of the short-tailed antthrush (Chamaeza campanisona) living in the Baturité Mountains of Brazil’s Ceará state are distinct enough to warrant classification as their own species: Chamaeza baturitensis (common name is the Baturité antthrush).
“Currently, 12 subspecies of Chamaeza campanisona are recognized, exhibiting a broad yet fragmented distribution across northern and central South America,” they explained.
The researchers analyzed 183 audio recordings of two Chamaeza campanisona subspecies (C. c. campanisona and C. c. tshororo) collected from across the Atlantic Forest region, combining traditional acoustic analysis with machine-learning tools.
The findings revealed three distinct song patterns among eastern South American populations.
Birds in the Baturité Mountains sing faster, longer songs than their relatives to the south, with no overlap in pace between the groups.
The researches analyzed 134 museum specimens of the two Chamaeza campanisona subspecies. In addition, they examined another 80 specimens through photographs.
They found that the new species lacks a small black patch above the bill that is present in the southern populations, and it has a buffier throat and chest.
“Morphologically, Chamaeza baturitensis is similar to Chamaeza campanisona but differs in lacking the black frontal spot and the yellowish lores characteristic of that species,” they said.
Chamaeza baturitensis is known only from two localities within a rainforest enclave of less than 100 km2.
These ‘sky islands’ formed during ancient climate shifts, when Atlantic Forest habitat expanded into the region and then retreated, marooning species in cooler, wetter mountain refuges.
“The species is restricted to the Baturité Mountains, a highland rainforest complex locally known as Brejos de Altitude, surrounded by the seasonally dry Caatinga, in the municipalities of Guaramiranga and Pacoti, Ceará, northeastern Brazil, north of the São Francisco River,” the scientists said.
The authors note Chamaeza baturitensis faces threats from poaching and has not yet been evaluated for conservation status.
“Because it has not previously been recognized as a distinct lineage, Chamaeza baturitensis is not included in current national or global threat assessments,” they said.
“Nevertheless, given its estimated extent of occurrence of less than 100 km2 and its apparent dependence on well-preserved forest understory, the species should currently be treated as Data Deficient until population studies allow a robust assessment of its conservation status.”
The discovery of Chamaeza baturitensis is reported in a paper published in the journal Zoologia.
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Lucas Romero et al. 2026. Revealing cryptic diversity: vocal and morphological evidence for a new species of Chamaeza (Aves: Formicariidae). Zoologia 43: e25083; doi: 10.1590/S1984-4689.v43.e25083