A new species of Tinamus (Aves: Tinamiformes) from the western Amazon, Brazil

We describe Tinamus resonans sp. nov., a new species of tinamou from the montane forests of the Serra do Divisor, western Amazonia, Brazil. The species is distinguished by a unique combination of plumage pattern, vocal repertoire, and ecological characteristics, including a conspicuous dark slate facial mask, vivid rufous-cinnamon underparts, and a uniform brownish-gray back. Its vocalizations are remarkable, consisting of long and powerful songs that echo strikingly across the steep montane slopes, producing a characteristic resonant effect.

The species was documented exclusively at higher elevations within a transitional zone between submontane and stunted forests, where the understory is densely structured by root mats. A preliminary population estimate, based on field detections and spatial extrapolation, suggests approximately 2,106 individuals restricted to the Serra do Divisor massif.Although no immediate anthropogenic pressures were observed within its range, the species may be highly vulnerable to climate change and to proposed infrastructure projects that threaten the integrity of this federally protected region.

The discovery of T. resonans highlights the biological uniqueness of the Serra do Divisor, reinforces its status as a center of montane endemism, and underscores the critical importance of maintaining its long-term conservation.