Two New Howler Monkey Species Discovered in the Amazon After 84 Years
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An international research team, including scientists from CIBIO-BIOPOLIS, has identified two new species of howler monkeys in the Amazon rainforest, ending an 84-year hiatus in descriptions for this genus and warning of urgent extinction risks driven by deforestation.
An international research team, including scientists from CIBIO-BIOPOLIS, has identified two new species of howler monkeys in the Amazon rainforest, ending an 84-year hiatus in descriptions for this genus and warning of urgent extinction risks driven by deforestation.
An international genomic investigation led by scientists from the University of Salford, in collaboration with CIBIO-BIOPOLIS (Research Centre in Biodiversity and Genetic Resources, University of Porto), has formally described two new primate species: the Mato Grosso red howler (Alouatta matogrossensis) and the Pantepui red howler (Alouatta iroi). Published in the journal Communications Biology, the study combines high-resolution genomic analyses with detailed morphological comparisons of historical museum specimens, including collections preserved at the National Institute of Amazonian Research (INPA) and new field data.
The findings resolve two chronic shortcomings in biological science: the Linnean shortfall (the true number of living species) and the Wallacean shortfall (their precise geographical distribution). Over millions of years, the dynamics of major Amazonian rivers isolated primate populations on opposing banks, fostering independent evolutionary trajectories that had previously gone undetected.
Amazonian rivers as biogeographical barriers
To reconstruct the most comprehensive evolutionary history of this primate group to date, the team sequenced the genomes of 11 howler monkey species across South and Central America. Howler monkeys are large arboreal primates renowned for their powerful vocalisations, the loudest among all land animals, which echo for kilometres across tropical forests to defend territories and maintain troop cohesion. The study provides empirical proof that the Amazon, Branco, and Xingu rivers served as permanent natural barriers, preventing gene flow and driving speciation across these riverine boundaries.
Critical conservation alert in the "Arc of Deforestation"
This research represents the first description of new species within the genus Alouatta since 1940, the year the Red howler, Alouatta puruensis, was documented. Alongside this taxonomic milestone, the authors issue a pressing conservation alert. The distribution range of A. matogrossensis, endemic to central Brazil, overlaps directly with the southern Amazonian "Arc of Deforestation". In this region, severe habitat loss and fragmentation caused by agricultural expansion place these newly recognized primate populations under severe threat of extinction.
Scientific Article:
Batista, R., Semedo, T.B.F., Beck, R.M.D. et al. (2026). Genome-wide analyses reveal recent diversification and hidden diversity in Amazonian howler monkeys, including two new species. Commun Biol. https://doi.org/10.1038/s42003-026-11187-8