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Wildlife conservation is a great responsibility that we should achieve. Specific actions such as reintroductions, based on the intentional movement and release of a species inside the indigenous range from which it disappeared, are a good way to achieve it. Unfortunately, more than a third of reintroductions (which are very expensive!) fail due to the lack of previous studies, an inadequate follow-up or a low genetic diversity. Genetic diversity at population level matters, but it is crucial when populations are small, as is usual in reintroduced species. The problem lies in the fact that low genetic diversity reduces the capacity to adapt to new environments.

A poorly planned reintroduction: the case of the Alpine marmot (Marmota marmota)

The Alpine marmot became extinct in the Pyrenees more than 15,000 years ago. Between 1948 and 1988 around 400 individuals were reintroduced in the French Pyrenees from the French Alps population (although the exact number or location where they were taken from is unknown). Marmots quickly settled and colonized almost the entire southern side of the Pyrenees.

Thanks to a bit of fur used for DNA extraction and a collaboration between LBBE (Laboratoire de Biologie et Evolutive Biometrics, Lyon, France) and CREAF (Center for Ecological Research and Forestry Applications, UAB), we discovered that the three Pyrenean populations studied (Andorra, Cerdanya and Ripollès) have low genetic diversity, come from two alpine populations and have not exchanged genetic material between them. More specifically, the marmots of Andorra and Cerdanya come from Mercantour, situated in the Southern Alps; while the Ripollès population comes from Vanoise, in the northern Alps. As the populations in the Pyrenees have not exchanged genetic material, each one is still closely related to their native population from the Alps.

Despite a lack of planning, a lack of monitoring and the low genetic diversity of the studied populations, the reintroduction of the alpine marmot has been a success in the Pyrenees. Nevertheless, we should take this success as an exception. It is worth highlighting the need for choosing an adequate number of individuals to reintroduce and for choosing genetically diverse individuals to increase the number of successful reintroductions. Currently few cases have included genetic diversity as a key for the selection of reintroduced specimens. One last issue to be resolved is whether Alpine marmots will be able to adapt to the new environment generated by climate change with this low genetic diversity.



Nature Reserve of the Grande Sassière (French Alps), where a part of the research has taken place.
Image by Carole et Denis Favre-Bonvin.