Artificial intelligence and vocal analysis reveal hidden biodiversity in Amazonian antbird populations across major river barriers

AI and bioacoustics reveal that a common Amazonian antbird is actually five species, including the newly described Cercomacra mura and C. raucisona.

By: AXL Media

Published: Mar 4, 2026, 9:30 AM EST

Decoding the Cercomacra cinerascens complex

The Amazon Basin is home to Earth's richest ecosystems, yet much of its biodiversity remains hidden within "species complexes"—groups of organisms that appear nearly identical but are biologically distinct. A research team from São Paulo State University (UNESP) and the University of São Paulo Museum of Zoology recently focused on the Grey Antbird (Cercomacra cinerascens). While these small, insect-eating birds exhibit almost identical plumage patterns, their vocalizations suggest a far more complex evolutionary history. By integrating artificial intelligence with traditional taxonomy, the researchers proved that what was once considered a single widespread species is actually a group of five distinct lineages.

AI powered bioacoustics and BirdNET technology

To distinguish between the nearly identical birds, the team employed BirdNET, an advanced machine-learning algorithm developed by the Cornell Lab of Ornithology. This AI tool converts complex bird songs into numerical data, enabling a precise, automated comparison of recordings collected from across the Amazon. Because birds rely heavily on acoustic signatures for species recognition and mate selection, these vocal differences serve as a powerful diagnostic tool. The AI analysis identified unique song structures that had previously been overlooked by human ears, providing the "acoustic signature" necessary to unlock the group's hidden diversity.

Discovery of two new avian species

The study led to the formal description of two new species. The first, Cercomacra mura, was named in honor of the Mura people, the Indigenous inhabitants of the western Amazon where the bird is found. The second species was named Cercomacra raucisona, derived from the Latin words for "hoarse" and "sound." This name reflects the bird's most diagnostic trait: a song composed entirely of two-note, raspy phrases. These discoveries demonstrate that even among relatively well-known bird groups, cryptic species remain undocumented due to their subtle morphological differences and reliance on non-visual communication.