The Critically Endangered Hainan gibbon (Nomascus hainanus) is the world’s rarest ape, with a single population of an estimated 25 individuals surviving in approximately 15 km² of suboptimal forest within Bawangling National Nature Reserve, Hainan, China. The existing biological evidence-base for the species is inadequate for conservation planning, precluding evaluation of appropriate recovery actions. I derived comprehensive new baseline data on Hainan gibbon ecology, behaviour and genetics to clarify the species’ biology and population status, and inform urgently required conservation management for the species. Rigorous re-evaluation of Hainan gibbon spatial requirements indicated the species’ home range is much smaller than previously estimated (c. 1.5 km²) and in line with closely related Nomascus species in similar ecological conditions. Molecular assessment of the genetic status of the surviving population within the context of the species’ historical genetic diversity revealed that the Hainan gibbon has suffered a significant decline in genetic diversity following its past population bottleneck. The current population also shows a high level of relatedness and male-biased offspring sex ratio. Predictive models examining reportedly ‘anomalous’ Hainan gibbon ecological and behavioural traits within a phylogenetic framework indicated that large, polygynous groups may be evolutionarily characteristic for the species, but home range requirements are influenced by both intrinsic factors and current extrinsic conditions. Finally, Population Viability Analysis demonstrated that the species is highly likely to become extinct in the near future without active management, and that multiple actions mitigating extrinsic threats, enhancing habitat carrying capacity and improving survivorship will be required to reduce extinction risk. Together, these findings suggest that landscape-level management actions and intensive manipulation of the population may be necessary to safeguard the future of the Hainan gibbon. This research also has wider implications for improved understanding of gibbon ecology and conservation of species of extreme rarity.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:631917 |
| Date | January 2014 |
| Creators | Bryant, J. V. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1434514/ |
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