A rich conservation history

The European bison or wisent (Bos bonasus) is Europe’s largest terrestrial animal species and a conservation icon. After centuries of facing constant pressure from humans, the last European bovine was finally extinct in the wild in the late 1920s. Only surviving in few zoos and private collections the current global population goes back to only 12 founders. Back then, only few dedicated people initiated and carried out an ambitious breeding programme to save the wisent from the brink of extinction. Here, I find it especially inspiring that this Polish-German project survived the unparalleled circumstances of World War II, and as a result the European bison survived as well. Nevertheless, this big bovine is still threatened today due to those severe bottleneck events and the resulting low genetic variability. Conservation genetics tries to tackle the resulting issues with modern methods.

Our applied focus

Our work is just one of several noteworthy publications with the focus on conservation genetics around the European bison. Sadly, papers often present large marker sets for only one application, only applicable on high-quality samples, based on marker systems, such as microsatellites, just failing to provide sufficient molecular resolution to resolve genetic questions properly, or are certainly not easy for immediate implementation in conservation programmes. This has something to do with the very low intraspecific genetic diversity present in this species but also how the research is published.

The achieved goal for us was to develop a cost-efficient, standardised, easy-to-use, optimised, and non-invasive SNP panel, which tackles several applications relevant in wisent conservation. Therefore, we worked closely together with stakeholders from ex situ and in situ conservation to create a marker set that really meets the needs of the conservation community around the European bison. Consequently, I also decided to address the paper’s discussion clearly not only to the scientific community but also to the conservationists in order to answer their upcoming questions. One of the biggest challenges was certainly to make all the different analyses work based on only 96 SNPs and low-quality samples such as dung. Adult European bison defecate 5 – 7 kg dung per day, which makes it an interesting source for genetic material in a genetic monitoring.

Conservation genetics is a relatively young and an explicitly applied research field. Although, publications in conservation genetics often promote the field applicability, I found it noticeable that often crucial information is missing to actually apply the presented and important genetic work. In our publication we provide extensive supplementary material on the optimal dung sampling methodology, genetic analysis, detailed marker information and a large set of 253 individual reference genotypes to maximise the explanatory power of analyses with new data of upcoming follow-up projects.

The potential future

Strictly developed for the European bison, we tested the SNP panel and all its applications on further ten Bovini species in 16 ESUs. The new sex marker can be utilised for all tested Bovini, whereas individualisation is possible on American bison, domestic cattle, gaur, and banteng even between first-degree relatives. Without any adjustments the SNP panel can be implemented in basic genetic monitoring for those partly conservation-relevant species. The interchangeable panel design regarding the markers allows to further develop and improve the marker set or use it as the foundation for new panels e.g. for the mentioned other bovine species. In prospect, we included posthitis-associated SNPs, which we could not test due to the lack of clinical data of our samples. But we invite to use the new marker panel for further research.

Why zoos can be important for conservation genetics

The representativity of the panel itself and the comprehensive population analysis was only possible due to the cooperation with 37 zoos and other holders across eight European countries: Our simplified sampling protocol proved to be handy and efficient by being followed by more than 90 sample collectors. The ex situ population is still the source for reintroduction and holds the highest genetic variability and therefore reduced the ascertainment bias for the final panel. More then 100-year-old pedigree data from those zoo populations provided a unique chance to validate the new panel’s molecular genetic results with the genealogical data. This research project and the development of this conservation tool would have been impossible without those scientifically managed zoo populations. The successful cooperation between zoos, conservation and scientific research shows which important role zoos can play besides e.g. environmental education or breeding programmes. This is an example on how zoos can contribute directly to in situ conservation beside providing animals for reintroductions or raising money. The European bison is again a blueprint on how zoos can play a central role in species conservation.

The successful application

The new panel was already utilised in some management issues in a Dutch zoo and has been implemented in the genetic monitoring of a rewilding project in the Țarcu Mountains, Romania (LIFE RE-Bison; LIFE14 NAT/NL/000987). A continuous genetic monitoring allows not only for the observation of the populations but also the evaluation of costly and laborious reintroduction efforts in the first place. We hope that the new panel can contribute crucial information for the difficult decision-making in such projects.

Again, this project around the SNP panel for the European bison was a fruitful research cooperation between Polish and German research institutions (Mammal Research Institute PAS Białowieża and Senckenberg Research Institute and Natural History Museum Frankfurt) and follows the tradition of former efforts in wisent conservation. We hope that this novel marker panel is used to improve the work of conservationists and will be utilised by follow-up research projects.