Mayor, P. | bioRxiv Science

bioRxiv2025

The genomic landscape of spider monkeys and northern muriquis from a conservation perspective

BackgroundMost populations of spider monkeys (Ateles) and muriquis (Brachyteles), two Neotropical primate genera, are under severe anthropogenic threats. Yet, taxon-wide population-level studies leveraging their degree of endangerment linked to their genetic diversity patterns and demographic history are lacking. To properly address this, there is a need to expand from morphological and genetic marker-based studies. ResultsWe generated high-coverage genome sequencing for 58 individuals sampled across 8 Atelidae species, in the first population-wide study of all extant spider monkey species, in the wild and captivity, alongside northern muriquis (Brachyteles hypoxanthus). Additionally, we present a high-contiguity reference genome for Ateles hybridus. Here, we observe the overall levels of genetic diversity and genetic load of the analyzed populations do not align to their IUCN endangerment category. Moreover, we show that in the wild, genetic load is overall higher compared to the captive populations analyzed. Then, we depict two main trans and cis-Andean sister clades in Ateles, and further structure and dynamics outlined by the Madeira River in the latter clade. Lastly, we find that genes in highly divergent regions between Ateles and B. hypoxanthus are involved in central nervous system development and photorreception. ConclusionsOur study shows i) the lack of concordance between the genetic diversity levels and extinction risk of these populations, suggestive of recent and strong external drivers; ii) increased genetic load in the wild in contrast to effective captive management, indicating mostly past demographic events; iii) structure and dynamics in spider monkeys that agrees with common biogeographical patterns and iv) genetic divergence between Ateles and Brachyteles potentially linked to distinct environmental light levels.

genomics↗

bioRxiv2020

Mysterious disappearances of a large mammal in Neotropical forests

The drivers of periodic population cycling by some animal species in northern systems remain unresolved1. Mysterious disappearances of populations of the Neotropical, herdforming white-lipped peccary (Tayassu pecari, henceforth "WLP") have been anecdotally documented and explained as local events resulting from migratory movements or overhunting2,3,4, or as disease outbreaks5,6, and have not been considered in the context of large-scale species-specific population dynamics. Here we present evidence that WLP disappearances represent troughs in population cycles that occur with regular periodicity and are synchronized at regional and perhaps continent-wide spatial scales. Analysis of 43 disappearance events and 88 years of commercial and subsistence harvesting data reveals boom - bust population cycles lasting from 20 to 30 years, in which a rapid population crash occurring over 1 to 5 years is followed by a period of absence of 7 to12 years and then a slow growth phase. Overhunting alone cannot explain the crashes, but as in northern systems dispersal during the growth phase appears to play a key role. This is the first documentation of population cycling in a tropical vertebrate.

ecology↗