Transfrontier lion conservation: applying genetics across time and space
Creators: name: Dures, Simon George
Publisher: name: Imperial College London
Year: 2016

description: As global landscapes and habitats become increasingly fragmented under pressure imposed by anthropogenic development, it is essential that we gain a better understanding of species functional responses to such change and the degree of connectivity between populations. I use African lions (Panthera leo) as model species and ask how natural and anthropogenic barriers affect lion dispersal across the multiple geopolitical boundaries of the Kavango-Zambezi Transfrontier Conservation Area (KAZA-TFCA). A better understanding of inbreeding depression, gene flow, loss of genetic diversity and the implications of genetic supplementation are all highlighted by the IUCN Cat Specialist Group as important for guiding future conservation plans. This research will give conservation stakeholders an insight into how these genetic factors can be influenced by the management of landscapes and populations with a view to improving the chances of long-term conservation success. Using genetics to assess functional connectivity, I determine the important isolating mechanisms across the landscape, testing both environmental and anthropogenic drivers, with a view to guiding future management of this mammal. I demonstrate how genetics can reveal unexpected cryptic patterns of gene flow that more traditional methods may miss. Furthermore, I identify patterns of gene flow and dispersal across the landscape to assess the feasibility of the KAZA TFCA to successfully conserve the species. Incorporating DNA from 19th century museum collections, I develop an assessment of how population genetic diversity has changed over time, with respect to human activities, and its relevance to conservation status. The results of the genetic analysis are finally incorporated into a population viability assessment to predict how potential future management actions are likely to affect the persistence of this lion population, one of the last remaining lion strongholds in Africa. The results demonstrate that the lion population is differentiated into two distinct genetic groups, one inhabiting the wetland Okavango Delta and the other inhabiting the surrounding dryland Kalahari. Further genetic substructure divides the population into distinct units, largely corresponding to the Wildlife management zones of the KAZA protected area network and likely a consequence of fragmentation, but which could realistically be reconnected given appropriate management of the intervening habitat matrix. Analysis of the historical samples identifies a considerable decline in the genetic diversity of this lion stronghold corresponding with the arrival of European settlers to the region, and a likely increase in persecution of the species and landscape alteration. Finally, modelling of future management scenarios suggests that continued fragmentation of the area, through increased habitat encroachment or even intensive management interventions such as fencing, will likely lead to a dramatic decline in the population due to the effects of inbreeding depression. Conversely, given the reconnection of the protected area network and therefore the promotion of low-level dispersal, my analysis predicts the long-term persistence of the lion population in this region.