Genetic assessment of an isolated endemic Samango monkey (Cercopithecus albogularis labiatus) population in the Amathole Mountains, Eastern Cape Province, South Africa

Abstract

The endemic Samango monkey subspecies (Cercopithecus albogularis labiatus) inhabits small discontinuous Afromontane forest patches in the Eastern Cape, KwaZulu-Natal midlands and southern Mpumalanga Provinces in South Africa. The subspecies is affected by restricted migration between forest patches which may impact on gene flow resulting in inbreeding and possible localized extinction. Current consensus, based on habitat quality, is that C. a. labiatus can be considered as endangered as the small forest patches they inhabit may not be large enough to sustain them. The aim of this study was to conduct a molecular genetic investigation to determine if the observed isolation has affected the genetic variability of the subspecies. A total of 65 Samango monkeys (including juveniles, subadults and adults) were sampled from two localities within the Hogsback area in the Amathole Mountains. Nuclear and mitochondrial DNA variation was assessed using 17 microsatellite markers and by sequencing the hypervariable 1 region (HVR1). Microsatellite data generated was used to determine population structure, genetic diversity and the extent of inbreeding. Sequences of the HVR1 were used to infer individual origins, haplotype sharing and haplotype diversity. No negative genetic factors associated with isolation such as inbreeding were detected in the two groups and gene flow between groups can be regarded as fairly high primarily as a result of male migration. This was in contrast to the low nuclear genetic diversity observed (H = 0.45). A further reduction in heterozygosity may lead to inbreeding and reduced offspring fitness. Translocations and establishment of habitat corridors between forest patches are some of the recommendations that have emerged from this study which will increase long-term population viability of the subspecies.

Climate refugia for three Afromontane forest‐dependent bird species in south‐eastern South Africa

“…Although climatic suitability for these species was diminished at higher elevations during the LGM (Figure 4g–i), pockets of climatic refugia may have persisted along the Transkei Escarpment (Baziya) and Amatole Mountains (Kubusi and Fort Fordyce). Observed genetic diversity unique to these forests (Table S2; Figure 2b–d) suggests that these birds may have been present in such mid‐elevational areas during the LGM, corroborating genetic diversity trends within regional Afromontane forests (Velvet worms: Daniels et al, 2017; Barnes & Daniels, 2019; birds: Coetzer et al, 2020; Mulvaney et al, 2021; frogs: Kushata et al, 2020; monkeys: Madisha et al, 2018; chameleons: da Silva & Tolley, 2017).…”

Species–landscape interactions drive divergent population trajectories in four forest‐dependent Afromontane forest songbird species within a biodiversity hotspot in South Africa

“…The South African endemic C. dichroa displayed the highest population structuring (Figure 5a), and the large genetic variability unique to Kubusi (Figure 6b) affirms the climatic refugial importance of the eastern Amatole forest complex (Dalton et al, 2015;Kushata et al, 2020;Madisha et al, 2018). The higher population complexity of this forest specialist contrasts with that of the forest generalist B. capensis, which is near endemic to South Africa, and more genetically diverse than C. dichroa (Table 1).…”

Influence of food availability, plant productivity, and indigenous forest use on ranging behavior of the endangered samango monkey (Cercopithecus albogularis schwarzi), in the Soutpansberg Mountains, South Africa

“…This dietary flexibility may account for the geographic range of the samango monkey extending to more southerly latitudes in comparison to other forest guenons (Wolfheim 1982;Coleman & Hill 2014a), and also facilitates the ranging of samangos into matrix habitat during periods of fruit scarcity (Lawes 1990;Skinner & Chimimba 2005;Nowak et al 2017;Wimberger et al 2017). Despite this, they are heavily reliant on food items located within patches of indigenous forest (Nowak et al 2017;Wimberger et al 2017) and are therefore reluctant to disperse over large stretches of open ground and inhabit small or isolated forest fragments (Lawes 1992(Lawes , 2002Lawes et al 2000;Madisha et al 2018). Understanding the factors that influence ranging patterns of the samango monkey is critical, therefore, for assessing the extent to which they can persist in an increasingly fragmented and human-dominated landscape.…”