Genetic diversity in ex situ populations of the endangered Leontopithecus chrysomelas and implications for its conservation

Leontopithecus chrysomelas, the Golden-headed Lion Tamarin (GHLT), is an endangered and endemic Neotropical primate from the Atlantic Forest of Brazil that has suffered a reduction of its habitat and population size in the wild. Ex situ populations have been established as a relevant alternative to safeguard the species and retain its genetic diversity and evolutionary potential. This study evaluated the genetic diversity and structure of the two main Brazilian captive populations of GHLT, which have been under human care at the Primatology Center of Rio de Janeiro (CPRJ) and the Zoological Park Foundation of São Paulo (FPZSP). Our results revealed levels of genetic diversity overall comparable to those observed for other Leontopithecus species and for ex situ and in situ populations of GHLT previously studied. Bayesian and principal coordinate analyses showed a moderate differentiation between CPRJ and FPZSP populations. Both populations presented observed heterozygosity values higher than expected heterozygosity values for most of the microsatellites used in this study, suggesting that the management has been efficient in avoiding an increase in homozygosity. However, simulations point to a significant loss of genetic diversity in the next 100 years, mainly in the FPZSP population. Such data are relevant for further decision-making on the metapopulation management of L. chrysomelas in captive conditions and for integrating in situ and ex situ conservation plans.

First detection of antibodies against Leptospira among free-ranging neotropical non-human primates in the Peruvian Amazon lowland rainforest

Leptospirosis is a bacterial zoonotic disease with multiple serogroups that infects wildlife and humans alike. Several studies have detected the presence of leptospiral antibodies in captive Neotropical primates, suggesting that they are asymptomatic carriers. However, the presence of antibodies in free-ranging primates and their potential role as reservoirs for this pathogen is not known. In this study, we used the Microscopic Agglutination Test (MAT) to screen two species of free-ranging tamarins for the presence of Leptospira antibodies using a panel of 21 serogroups. A total of 56 primates (26 Leontocebus weddelli and 30 Saguinus imperator) were screened at the Estación Biológica Río Los Amigos in Madre de Dios, Peru. MAT results with titres of ≥100 in single samples were considered seropositive. Prevalence ratios (PR) were estimated for age group, sex and host species identity. Overall, 51.8% (29/56) of animals were reactive for at least one Leptospira serogroup. Serogroups were distributed as follows: Iquitos (41.1%), Icterohaemorrhagiae (14.3%), Sejroe (3.6%), Autumnalis (1.8%) and Bataviae (1.8%). No significant differences (p > .05) were found for seropositivity frequencies among categories within assessed variables. These results suggest that free-ranging L. weddelli and S. imperator might serve as reservoirs for pathogenic Leptospira serogroups. Given increasing human-wildlife contact, future studies that test for active infection are required to determine potential transmission risks to humans.