A previously unrecognized species of the antthrush genus Chamaeza has been discovered in the isolated highland rainforests of northeastern Brazil, researchers report in the journal Zoologia.
The new species — named Chamaeza baturitensis, or the Baturité antthrush — was found in the Baturité Mountains of Ceará state, a highland rainforest complex known as the Brejos de Altitude, surrounded by the dry Caatinga scrublands. 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.
An international team analyzed 183 audio recordings of two Chamaeza campanisona subspecies collected across the Atlantic Forest, 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.
Morphological work on 134 museum specimens plus another 80 birds examined through photographs backed up the vocal evidence. The new species lacks a small black patch above the bill present in the southern populations and has a buffer throat and chest.
"Chamaeza comprises ground-dwelling suboscine birds specialized for life in the understory of Neotropical forests," said Universidade Estadual Paulista ornithologist Vagner Cavarzere and 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."
Chamaeza baturitensis is known from only two localities within a rainforest enclave of less than 100 km², in the municipalities of Guaramiranga and Pacoti. The authors note the species faces threats from poaching and has not yet been evaluated for conservation status. Given its tiny range and apparent dependence on well-preserved forest understory, they recommend treating it as Data Deficient until population studies allow a robust assessment.
