Long believed to be a single species found throughout the Amazon rainforest, ant birds are, in fact, a group of different species, including two newly identified ones: Cherkomakra village and Cercomacula laucisona. These species inhabit distinct areas of the southern Amazon. This revelation was made possible through an extensive analysis of museum specimens and bird audio recordings. Discover more about the gray ant bird (Sercomacra cinerasense), which further complicates our understanding.

The gray antbird is a small, inconspicuous bird native to forested areas. These birds thrive in dense understory habitats across Brazil, Bolivia, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela.

Males typically exhibit gray plumage while females appear brownish, making it challenging for ornithologists to differentiate between various populations in this vast geographical region.

To reassess species boundaries, researchers led by Sercomacra cinerasense expert Wagner Cavalzere from the University of Complex conducted comparative studies on feather coloration, body measurements, and vocalizations.

The study analyzed 682 bird specimens from museum collections and evaluated 347 song recordings.

The team employed BirdNET, a deep learning platform designed to classify bird calls, to assess song structure.

“Birds rely heavily on vocal communication, which is crucial for species recognition,” the researchers stated.

“Their songs serve as sonic signatures, essential for uncovering hidden diversity.”

The findings indicated distinct divisions in populations separated by major Amazonian rivers.

Birds residing north of the Pastaza, Maranhão, Solimões, and Amazon rivers exhibited consistent differences in coloration and song patterns compared to southern populations.

Cherkomakra village is found in the forested region between the Ucayali and Madeira rivers, while Cercomacula laucisona inhabits areas between the Madeira and Tapajos rivers.

“These rivers act as long-standing natural barriers,” the researchers noted.

“The populations have diverged independently over millennia to evolve into the unique species we describe today, isolated by these significant rivers.”

Cherkomakra village. Image credit: Tomas Melo.

Additionally, scientists recognized several previously named forms as distinct species, bringing the total in this complex to five.

Each species is characterized by unique vocal traits and geographical ranges, with minimal evidence of overlap or hybridization.

This discovery underscores the vast unexplored biodiversity within the Amazon, revealing complexities among bird species previously thought to be well understood.

“By integrating artificial intelligence with fundamental bioacoustics and museum collection studies, we uncover diversity that would otherwise remain invisible,” the authors emphasized.

“Acknowledging these species is crucial for their conservation in a rapidly changing environment.”

For further details on this discovery, refer to the new paper published in Vertebrate Zoology.

_____

V. Cavalzere et al. 2026. Integrated taxonomy of Sercomacra cinerasense Species complex with descriptions of two new species (Birds: Thamnophilidae). Vertebrate Zoology 76: 73-91; doi: 10.3897/vz.76.e171834