Genetic diversity in a little known lemur species from the north of Madagascar (Microcebus tavaratra)

Tese de mestrado. Biologia (Biologia da Conservação). Universidade de Lisboa, Faculdade de Ciências, 2011Estudos sobre a delimitação das espécies e genética populacional providenciam-nos informação sobre a evolução das espécies assim como a sua resposta natural às pressões antropogénicas. Ainda assim, para muitas espécies, esses efeitos ainda não foram estudados e necessitam de mais investigação (Hanski et al., 1998). Este é o caso dos lémures rato (género Microcebus) que habitam as florestas de Daraina. Foi sequenciado o ADN mitocondrial de 72 indivíduos Microcebus, cujas amostras tinham sido recolhidas em três fragmentos de floresta, de modo a determinar se eram todos membros da mesma espécie, a M. tavaratra, uma vez que dois outros indivíduos desta espécie já tinham sido identificados nesta região (Weisrock et al., 2010). É importante perceber como a diversidade genética é distribuída tanto para os genes mitocondriais como para os nucleares (microsatélites), uma vez que o rio Manankolana e outros aspectos ecológicos de Daraina já demonstraram desempenhar um papel importante na estrutura genética de algumas populações (Quéméré et al., 2010; Radespiel et al., 2008). Os resultados sugerem que todos os indivíduos pertencem à espécie M.tavaratra e que é mantida uma grande variabilidade genética nas populações de Bekaraoka e Solaniampilana. Contudo, na floresta de Binara, a falta de diversidade genética em todos os mtADN loci é surpreendente. Por outro lado, os dados dos microsatélites demonstraram que afinal a população de Binara exibe variabilidade genética assim como as outras duas populações. Como tal, não foi possível identificar nenhuma estrutura populacional ao nível nuclear. Embora seja provável que este seja o estudo mais abrangente geograficamente sobre os Microcebus de Daraine, os resultados sugerem que é necessária mais investigação. Estudos como este são importantes para que se implementem planos de conservação coerentes e consistentes para as espécies em risco

notes on the present distribution and conservation of the sooty mangabey (Cercocebus atys) in Guinea-Bissau, West Africa

UIDB/04038/2020 UIDP/04038/2020The West-African sooty mangabey (Cercocebus atys) is threatened by habitat loss, hunting for meat consumption, and mortality during crop-foraging events. The species’ overall demographic trend is unknown. Presence and distribution in Guinea-Bissau, a country neighbored by Senegal and Republic of Guinea, was confirmed in 1946 but the species was declared extinct in 1989 and not observed in subsequent countrywide expeditions. Narratives of its presence across southern Guinea-Bissau are scattered in reports and occurrence in the eastern part was reported in 2017, but the limits of its distribution are currently unknown. Here, we present recent geo-referenced visual and molecular-based records of the sooty mangabey for three protected areas in southern Guinea-Bissau collected as part of a region-wide survey. Individuals were observed in Cufada Lagoons Natural Park (2015) and Dulombi National Park (NP) (2016) and photographed in Boé NP (2007, 2015 and 2020). Thirty-six samples collected in Boé NP (2017) were identified as sooty mangabey using a 402 base pair fragment of the mitochondrial cytochrome b gene. Our work suggests a wider distribution in Guinea-Bissau than previously described, augments knowledge of the populations’ current habitat use and threats, and has implications for efforts to conserve the species in West Africa. Considering the sooty mangabey as the reservoir of the simian immunodeficiency virus that led to the human variant, HIV-2, confirmation that the Guinea-Bissau population is not extinct may lead to a better understanding of early viral jump to humans and consequent epidemic spread, specifically of the HIV-2 Subgroup A. We highlight the need for extra conservation measures by Guinea-Bissau authorities.publishersversionpublishe

The importance of well protected forests for the conservation genetics of West African colobine monkeys

In tropical forests, anthropogenic activities are major drivers of the destruction and degradation of natural habitats, causing severe biodiversity loss. African colobine monkeys (Colobinae) are mainly folivore and strictly arboreal primates that require large forests to subsist, being among the most vulnerable of all nonhuman primates. The Western red colobus Piliocolobus badius and the King colobus Colobus polykomos inhabit highly fragmented West African forests, including the Cantanhez Forests National Park (CFNP) in Guinea-Bissau. Both species are also found in the largest and best-preserved West African forest—the Taï National Park (TNP) in Ivory Coast. Colobine monkeys are hunted for bushmeat in both protected areas, but these exhibit contrasting levels of forest fragmentation, thus offering an excellent opportunity to investigate the importance of well-preserved forests for the maintenance of evolutionary potential in these arboreal primates. We estimated genetic diversity, population structure, and demographic history by using microsatellite loci and mitochondrial DNA. We then compared the genetic patterns of the colobines from TNP with the ones previously obtained for CFNP and found contrasting genetic patterns. Contrary to the colobines from CFNP that showed very low genetic diversity and a strong population decline, the populations in TNP still maintain high levels of genetic diversity and we found no clear signal of population decrease in Western red colobus and a limited decrease in King colobus. These results suggest larger and historically more stable populations in TNP compared to CFNP. We cannot exclude the possibility that the demographic effects resulting from the recent increase of bushmeat hunting are not yet detectable in TNP using genetic data. Nevertheless, the fact that the TNP colobus populations are highly genetically diverse and maintain large effective population sizes suggests that well-preserved forests are crucial for the maintenance of populations, species, and probably for the evolutionary potential in colobines.info:eu-repo/semantics/publishedVersio

The importance of well protected forests for the conservation genetics of West African colobine monkeys

In tropical forests, anthropogenic activities are major drivers of the destruction and degradation of natural habitats, causing severe biodiversity loss. African colobine monkeys (Colobinae) are mainly folivore and strictly arboreal primates that require large forests to subsist, being among the most vulnerable of all nonhuman primates. The Western red colobus Piliocolobus badius and the King colobus Colobus polykomos inhabit highly fragmented West African forests, including the Cantanhez Forests National Park (CFNP) in Guinea‐Bissau. Both species are also found in the largest and best‐preserved West African forest—the Taï National Park (TNP) in Ivory Coast. Colobine monkeys are hunted for bushmeat in both protected areas, but these exhibit contrasting levels of forest fragmentation, thus offering an excellent opportunity to investigate the importance of well‐preserved forests for the maintenance of evolutionary potential in these arboreal primates. We estimated genetic diversity, population structure, and demographic history by using microsatellite loci and mitochondrial DNA. We then compared the genetic patterns of the colobines from TNP with the ones previously obtained for CFNP and found contrasting genetic patterns. Contrary to the colobines from CFNP that showed very low genetic diversity and a strong population decline, the populations in TNP still maintain high levels of genetic diversity and we found no clear signal of population decrease in Western red colobus and a limited decrease in King colobus. These results suggest larger and historically more stable populations in TNP compared to CFNP. We cannot exclude the possibility that the demographic effects resulting from the recent increase of bushmeat hunting are not yet detectable in TNP using genetic data. Nevertheless, the fact that the TNP colobus populations are highly genetically diverse and maintain large effective population sizes suggests that well‐preserved forests are crucial for the maintenance of populations, species, and probably for the evolutionary potential in colobines

Dietary flexibility of western red colobus in two protected areas with contrasting anthropogenic pressure

Food distribution and abundance can affect intra- and inter-dietary variation in non-human primates, influencing feeding ecology and altering behaviour. Natural and/or human-induced actions can influence the dynamics between primates and the environment, with associated impacts on socio-ecology and demography. This relationship in anthropogenic landscapes, however, is poorly understood. Here, we use DNA metabarcoding to obtain high resolution dietary diversity data, and multivariate generalised linear models to investigate variation in the diet of this threatened primate. We characterise the diet of the western red colobus (Piliocolobus badius) in both the better preserved Gola Rainforest National Park (GRNP, Sierra Leone), and in the fragmented forests of Cantanhez National Park (CNP, Guinea-Bissau), and evaluate biological, ecological and temporal differences. Dietary plant species richness was high in both protected areas, and the type of plants consumed varied significantly across seasons, space, and time. Although we identify dependence on a few key plants, red colobus in CNP consumed a higher average number of plant taxa than in GRNP, and 11% of the diet consisted of cultivated foods (e.g. mango). This is the first time a molecular approach has been used to investigate red colobus diet, and reveal dietary flexibility in degraded forests. Predicting the consequences of dietary change on long-term population persistence, however, remains a significant knowledge gap. Nevertheless, our results provide critical information to inform targeted regional conservation planning and implementation

The use of plants by human and non-human primates in altered landscapes: dietary flexibility or local adaptation?

Non-human primates foraging range and human populations currently overlap extensively in regions of extreme poverty. In these anthropogenic landscapes, people depend heavily on natural resources, sharing space and plants with sympatric non-human primates. To understand the complex social-ecological dynamics of such systems, an integrative approach was applied to evaluate the extent of wild plant overlap between co-existing humans, and western chimpanzees (Pan troglodytes verus) and western red colobus (Pilicolobus badius) in two national parks in West Africa. Despite being similar in area and demography, Gola Rainforest National Park in Sierra Leone is a semi-deciduous evergreen continuous forest devoid of villages and with low levels of human disturbance, and strong conservation enforcement. Cantanhez National Park in Guinea-Bissau is a mosaic of sub-humid and secondary forests, savanna, mangrove, and agricultural fields and settlements, with little formal protection of the forests and wildlife. High levels of wild plant use by humans were observed in both parks, with people from Cantanhez showing a greater ethnobotanical knowledge. Non-human primate diet across all populations revealed high plant species richness, generally higher in Gola forest. Primate populations at the disturbed site, demonstrated signs of dietary flexibility and consumed a greater number of cultivated items than primates in Gola. Overall, some wild and cultivated plant overlap was detected within each study site, but to a greater extent in the fragmented landscape of Cantanhez national park. Evidence produced in this research, together with local knowledge and expertise, can be incorporated to plan and implement ethical and sustainable conservation strategies and policies, that can conserve threatened primates and their habitat, and respond to people’s basic needs

The genetic structure of a mouse lemur living in a fragmented habitat in Northern Madagascar

International audienc

Genetic Differentiation and Demographic History of the Northern Rufous Mouse Lemur (Microcebus tavaratra) Across a Fragmented Landscape in Northern Madagascar

International audienc