Scientists have identified two new species of howler monkeys in the Amazon, marking the first such discovery in the last 85 years. The study, published in the journal Communications Biology, was based on the first genomic analysis of the genus Alouatta.
The researchers emphasized that this discovery underscores the importance of conserving Brazil's threatened ecosystems. Howler monkeys, which are the loudest terrestrial animals on the planet, belong to primates of Central and South America, known for their loud calls and vocalizations that can be heard up to five kilometers away.
These sounds are used to deter rivals without physical confrontation, mark territory, and communicate. The work was led by Dr. Romina Batista and Professor Jean Bubli, who work at the University of Salford in the UK. The team collected genetic data from 86 animals from the genus's range, including samples from museum collections. Among these samples were fragments of dried skin from two preserved howler monkeys from the Bavarian State Zoological Collection in Munich, Germany.
Romina Batista stated in her announcement: 'Our research shows that the Amazon still holds remarkable biological secrets, even among well-known animals like howler monkeys.'
The genomic analysis confirmed biologists' suspicions about the need to revise the classification of howler monkeys. The researchers distinguished two species; they also found that A. puruensis is not a valid species as it corresponds to A. juara. However, the Trinidad howler monkey (A. insulanus) may represent an independent species rather than just a subspecies, although this hypothesis requires further confirmation through nuclear DNA analysis.
Gene analysis allowed for the reconstruction of part of the evolutionary history of the genus Alouatta. The results indicate that the genus likely originated in Mesoamerica and subsequently spread throughout South America. The first divergences between howler monkeys from the two regions occurred approximately 3.5 million years ago, coinciding with the formation of the Isthmus of Panama land bridge.
The evolution of these primates was also influenced by the region's geography. The formation of large rivers, such as the Amazon, disrupted gene flow between populations, allowing them to evolve independently. The appearance of savannas in parts of the Amazon basin also separated habitats of species such as A. nigerrima and A. sara.
For scientists, a deeper understanding of this genetic diversity can help determine conservation priorities. Deforestation, climate change, and habitat loss threaten Amazonian species even before they are fully studied or discovered by science.
Jean Bubli noted: 'We hope that these findings will help conservation organizations identify the most vulnerable populations and prioritize protection efforts across the entire Amazon basin.'


