“The genus Tinamus makes up the little forest tinamous and is the most varied within the household Tinamidae, with 21 acknowledged types,”stated lead author Dr. Luis Morais from the Universidade Federal do Rio de Janeiro and his coworkers.

“Despite its variety, Tinamus stays among the least-studied bird groups in the Neotropics, mostly due to its puzzling practices and the inaccessibility of the thick forest environments it inhabits.”

“The western Amazon harbors the best variety of Tinamus types co-occurring within the very same area.”

“However, couple of research studies have actually dealt with the taxonomy of tinamous in this location, leaving a number of essential concerns unsolved.”

The scientists initially taped an unique vocalization of the brand-new types in 2021 in the understory of the Serra do Divisor, a separated mountain complex found on the border in between Brazil and Peru.

“The tune looked like those of Tinamusyet no types might be with confidence recognized at the time, and no visual verification was gotten,” they described.

“Comparisons with all Tinamus vocalizations understood from the area, along with assessments with ornithologists experienced in Amazonian avifauna, stopped working to produce a definitive match.”

“The tune appeared unlike any recognized tinamou vocalization, raising the hypothesis that it may represent an undescribed type.”

In 2024, the researchers was successful in bring in 2 people utilizing a digitally manufactured playback from earlier recordings, getting exceptional views and photos of one bird.

“During the field exploration to Serra do Divisor National Park, 5 acknowledged types of Tinamus were found: Tinamus bartletti Tinamus cinereus Tinamus soui Tinamus strigulosusand Tinamus variegatus,” they stated.

“All these types were taped in lowland forests and along the lower montane slopes.”

“In contrast, the only agent of the genus come across in the greater elevations of the mountains, above 250 m, were the specimens agent of the taxon here presumed as an undescribed types, showing a special mix of plumage pigmentation and singing structure, which we officially name as: Tinamus resonans (typical name is the slaty-masked tinamou).”

Throughout 10 independent encounters at 8 websites throughout the mountainous area of the Serra do Divisor, the authors with confidence determined a minimum of 15 unique people.

“Considering the overall degree of ideal environment within the specified elevational variety (63,302 ha), we approximate an initial population size of roughly 2,106 people in the Serra do Divisor mountain complex,” they stated.

Tinamus resonans is identified by a distinct mix of plumage pattern, singing collection, and eco-friendly attributes, consisting of a noticeable dark slate facial mask, brilliant rufous-cinnamon underparts, and a consistent brownish-gray back.

“This types varies from all other Tinamidae by providing, a minimum of in women (the 3 people whose sex might be figured out were female), an unique dark slate-colored crown, which extends into a popular stripe down the hindneck and into the post-ocular area, forming an obvious facial mask,” the ornithologists stated.

The vocalizations of Tinamus resonans are exceptional, including long and effective tunes that echo noticeably throughout the high montane slopes, producing a particular resonant result.

Tinamus resonans was tape-recorded vocalizing spontaneously throughout the late afternoon and sunset, in between 17:40 and 18:30 regional time,” they scientists stated.

“Its tune is loud and rollovers fars away, however goes through significant acoustic diffusion along the high slopes of the Serra, which modifies the temporal structure of the tune due to echo.”

“When faced straight, people revealed no avoidance habits and appeared incredibly tame, relatively stopping working to acknowledge human beings as possible predators.”

“In addition, people were observed crossing open locations of understory gradually and without indications of watchfulness, a habits contrasting with the generally cautious reactions of other tinamous.”

“Between singing reactions, birds were likewise observed foraging on the forest flooring, penetrating and reversing leaf litter with the expense looking for food products.”

According to the researchers, Tinamus resonans might be extremely susceptible to environment modification and to proposed facilities jobs in Brazil.

“The discovery of Tinamus resonans highlights the biological individuality of the Serra do Divisor, strengthens its status as a center of montane endemism, and highlights the crucial significance of preserving its long-lasting preservation,” they concluded.

Their paper was released on December 2, 2025 in the journal Zootaxa

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Luis A. Morais et al2025. A brand-new types of Tinamus (Aves: Tinamiformes) from the western Amazon, Brazil. Zootaxa 5725 (2 ); doi: 10.11646/ zootaxa.5725.2.6