FAQs
(Disclaimer - the following answers are based on years of research and reading, so a broad description is given, with a few links to relevant studies and publications where necessary)
1.) What is a population?
Frankham etal. (2010) state that there are 16 different definitions of a ‘population’ based on evolutionary, ecological and statistical criteria, but they define it as a “…group of individuals living in sufficiently close proximity that any member of the group can potentially reproduce with any other member”.
2.) What is a metapopulation?
The metapopulation is regarded as a population of populations (Primack, 1998), with moderately isolated groups that interact through migration and gene flow (Hanski & Gaggiotti, 2004). An example could be two proximal reserves or parks connected by a corridor that allows movement between them. HOWEVER...when it comes to large African mammals, natural gene flow between populations is now hindered by the fences that have been long established to keep the wildlife safe from poachers and avoid human-wildlife conflict with neighbouring communities around parks (apart from species such as cheetahs, leopards and elephants who occasionally do their own thing regardless of the fences). So the way we continue this metapopulation approach to management, despite the fences, is to relocate rhinos from one park to another. It is important to have as much biological information as possible on the animals being moved and where they are being moved to, to ensure they don't end up moving a reproductively dominant adult male to a park that recently acquired four of his daughters, for example.
3.) Why is genetic management important?
This has been a question of some debate for many decades, but a recent summary by Richard Frankham etal. (2014) states that genetic management is of critical importance to fragmented populations of endangered species regardless of current levels of inbreeding or low heterozygosity*. To simplify...the southern White rhino was classed as a conservation success story after recovering from a handful of surviving animals in KwaZulu-Natal in the 20th century, to the tens of thousands estimated to be living in southern Africa in 2007, before the recent poaching surge. But a consequence of a large number of animals growing from a small number of founders, is that their relatedness is likely to be very high, and subsequently the level of inbreeding as well. Inbreeding can have negative effects on a population/ species as it can lead to numerous birth defects, calf mortalities, and high susceptibility to diseases. Basically, if a new disease comes along that effects one animal in a population, it could quite feasibly affect all of them as there is no genetic variation in their immune response and ability to fight back. This could have catastrophic consequences for highly inbred endangered species. So the idea is that we do our best to PREVENT this catastrophe by maximising the number of mates available to reproductive adults in order to avoid the risk of them mating with siblings or parents.
*heterozygosity - this is the measure of genetic variation that accounts for the proportion of individuals in a population that are heterozygotes, i.e. an individual that has two different alleles at a particular chosen locus on the gene eg Aa, as opposed to a homozygote which would be AA or aa.
4.) So how does this project fit in?
In a nutshell...poaching in southern Africa has increased dramatically year-on-year since 2008 and we are reaching the critical stage where the loss of rhinos to poaching is actually greater than the number of births of new rhinos, i.e. population DECLINE! Consequently, managers are needing to move some rhino populations from high risk areas to safer parks with lower poaching rates, sometimes across borders, without the luxury of time to select the most suitable individuals to move. This research aims to advise managers on a few elements of the selection process that should improve the longterm establishment, growth and prosperity of these animals in their new populations, based on their genetic fitness, relatedness, and reproductive potential. I can't emphasise enough the urgency for these research outputs to reach the rhino owners and managers who can immediately apply them to future relocations/ reintroductions*.
I need to point out here, that this research has nothing to do with farming rhinos, as was interpreted by a visitor to my page. The sad reality is that NO rhinos exist anywhere in Africa without a fence around them, so wild and free is all relative these days. The aim here is to address management questions that have arisen during previous relocations of rhinos within South Africa, in order to enhance our current knowledge and understanding and build on what has been followed until now. The principle focus is improving the likelihood of new rhino populations thriving indefinitely, while anticipating and reducing genetic risks such as inbreeding.
* a relocation, or translocation as it is better known in wildlife terms, is the straightforward movement of an animal/ population from one area of its historical range to another. Whereas a reintroduction is the movement of an animal/ population BACK into an area it was historically extirpated from.
5.) I still don't quite understand the relevance!?
I will be adding to this section as topics arise that I believe need some clarity, but please feel free to use the Discussion and Message facilities on the site to ask me about anything I haven't yet covered.
Further reading:
Frankham, R., Ballou, J.D., and Briscoe, D.A. (2010) Introduction to Conservation Genetics, 2
Frankham, R., Bradshaw, C.J.A., and Brook, B.W. (2014) Genetics in conservation management: Revised recommendations for the 50/500 rules, Red List criteria and population viability analyses. Biological Conservation 170, pp. 56-63.
Hanski, I., and Gaggiotti, O.E. [eds] (2004) Ecology, Genetics, and Evolution of Metapopulations. Elsevier Academic Press, USA.
Primack, R.B. (1998) Essentials of Conservation Biology, 2
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