Two new howler monkey species described in the Amazon
· BehindLines newsroom
A team of geneticists has described two howler monkey species in the Amazon (Amazonie in French) that were not recognised before, in a study published on 30 October and relayed on 11 November by Mongabay. According to Mongabay, it also invites a fresh look at how several populations of the genus Alouatta are classified.
More than ten years of work
The research, published in the journal Communications Biology, rests on a genomic analysis covering 11 of the 13 recognised howler monkey species. According to Mongabay, it follows over a decade of field expeditions and specimen gathering. Its lead author, Romina Batista, works as a biologist for the University of Salford (United Kingdom) and for Brazil's National Institute of Amazonian Research, and went through more than 2 terabytes of unprocessed genomic data. Reviewing the results, she saw that the monkeys living along either side of the Rio Branco in northern Brazil belong to separate genetic lineages. Differences in appearance, among them the yellower coat of A. iroi, back up that finding.
Two red howler species
The team formally describes two red howlers from the Amazon: the Pantepui red howler (Alouatta iroi), found in the north-west, and the Mato Grosso red howler (Alouatta matogrossensis), found in the south of the Brazilian part of the region. According to Mongabay, the study further recommends treating the monkeys of Trinidad and Tobago (Trinité-et-Tobago in French) as their own species, A. insulanus, whereas they were formerly listed as A. seniculus insulanus. In the scientific paper, the authors estimate that most of the genus' Amazonian diversity appeared within the past million years, shaped by geographical barriers such as the rivers of the basin and the Andes mountains.
Museum collections put to use
According to Batista, quoted by Mongabay, historical specimens held by natural history museums helped identify distinguishing features. She takes this as a demonstration of why such collections should be preserved, since new tools make it possible to re-examine old specimens.
Threats to be assessed
The home range of A. matogrossensis overlaps Brazil's "arc of deforestation", where farming expansion has helped break up the forest. The researchers think it could be classed as "critically endangered", but no formal assessment has been made yet. According to Mongabay, the Bem Querer hydroelectric dam planned for the Rio Branco might also affect A. iroi and its near relative A. macconnelli. In Mato Grosso, the Reconecta project put up canopy bridges linking split-up forest patches; scientists have recorded A. matogrossensis crossing them, one of the animals being a mother with her young.
Why it matters
The scientists are circulating their distribution data among peers and the general public, which could feed into an IUCN assessment. Batista calls these results "a piece of the puzzle" for grasping how the region's biodiversity came about. The authors remind readers in the study that 11 of the 16 recognised howler monkey taxa are already listed as threatened by the IUCN.