Senckenberg Research

Genetic Wildlife Monitoring: Interface between Science and Species Conservation

 

Lynx
The lynx has returned to Germany due to successful reintroduction programmes in the Bohemian Forest and the Harz Mountains. Both credible sightings and genetic detections are extremely rare for this elusive predator.

  

 

Genetic wild animal monitoring is a method that enables us to keep track of rare species such as wolves, wild cats or beavers that prefer to keep themselves to themselves. Senckenberg scientists carry out genetic analyses on samples from hair, droppings or other traces left behind by the animals concerned. This provides an important basis for effective species protection. 

Non-invasive genetic studies on endangered wildlife – ‘invisible’ evidence

An important prerequisite for taking effective measures to protect threatened species involves gathering detailed information about chronological developments concerning their dissemination and abundance. However, in many cases, rare and secretive species are particularly difficult to observe directly, making effective monitoring problematic. This also applies to large and conspicuous species such as the wolf, lynx and wildcat, which in recent years have all begun to regain the territories that they lost after being practically exterminated in the 19th century.

In the Conservation Genetics Section at the Senckenberg station in Gelnhausen, genetic analyses of endangered wildlife species are being carried out to establish an interface between science and society, especially as represented by applied nature conservation. As cadavers of rare species are rarely found, the main emphasis is on the use of non-invasively collected samples such as fur, faeces, urine, blood and saliva residues. Through the use of highly sensitive genetic techniques such as microsatellite analysis, it is possible to draw conclusions about taxonomic status, the degree of hybridization, sex and population membership. Investigation of the genetic structure can also shed light on dispersal rates and migration corridors.

 

Map: Genetic wildcat detections in Germany
Genetic wildcat detections in Germany.
Analyses of the past three years (blue dots)
have significantly increased the known
range compared to the previously known
distribution (green area).

The wild cat as a ‘prototype’

We began the investigations in 2007 with the genetic monitoring of the wildcat (Felis silvestris) as part of the ‘Wildcat Safety Net’ species conservation project which was initiated by the BUN D nature conservation organization. Through the project, it was possible to collate hundreds of wildcat identifications. As a result, the Senckenberg genetic database contains approximately 2,000 genetically registered wildcat individuals. This represents a unique achievement that was only possible with the aid of a large number of volunteer workers who used a method involving lure sticks to attract the cats and obtain fur samples. Thanks to these analyses, the wildcat distribution map for Germany has been radically revised. In many regions, the presence of wildcats could be confirmed for the first time (e. g. Kellerwald National Park, the Odenwald, the Vogtland, the Rhön Mountains, the Rothaar Mountains and Styria). The experience gained with wildcats concerning the treatment of non-invasively gathered samples has since been adapted to suit many otherspecies, including wolves and beavers.

 

The return of the wolves: Wild animal research in the public eye

Timber wolf in the wildlife park Springe
Molecular biology meets wildlife –
to increase thereference data set,
genetic sampling may require approaching
animals in order to pluck hairs, as shown
here for a timber wolf in the wildlife park
Springe.

Since 2009, Senckenberg has been serving as a reference centre for lynx and wolf genetics in Germany. Alongside man, the lynx (Lynx lynx) and the wolf (Canis lupus) stood at the peak of terrestrial food webs in Europe for thousands of years until about 150 years ago. Lynxes were recently reintroduced to the Czech Republic, Switzerland and Germany (Bavarian Forest, Harz Mountains), amongst other places, whereas wolves have returned without human assistance. Coming from Poland, wolves entered the Lusatia region of Saxony and Brandenburg and have spread further into Germany since the first recorded case of reproduction in 2000. For the past three years, scientists from the Senckenberg research station in Görlitz, state officials and the LUPUS Office of Wildlife Biology have been cooperating closely. Now the Polish part of the so-called German-Polish wolf population has been included in the analyses, and this year has seen a comprehensive picture emerge.

For the first time, it was possible to provide precise details of pack structures, movements and the degree of hybridization of German wolves during the annual experts’ meeting at the Federal Agency for Nature Conservation. It could be shown that, since a case of hybridization that occurred in the early years of the wolves’ return and attracted public attention at the time, there have been no more wolf-dog hybrids in the wild. It was also possible to trace the origins of most of the wolves found in the western part of Germany. Some of them come from the core group in Lusatia. However, one wolf that was hit by a car this year in Hesse and then shot by a hunter in the Westerwald is descended from the Alpine population. This group can be clearly defined genetically, and it has been spreading from the Apennines via the Alps for several decades. Wolves have regularly been shown to undertake such long migrations as the ‘Westerwald Wolf’ apparently did. This underlines the need for networking between wolf experts across regional and national boundaries, as Senckenberg is doing.

Reintroduction of beavers in Central Europe: Success ful nature protection or fals ification of th e fauna?

Map of the genetic structure of beaver samples in Germany and adjacent regions
Genetic structure of beaver samples in Germany and adjacent regions.
Colours reflect the affiliation to a genetically defined populations
(red = C. canadensis, green = C. f. albicus, light blue = C. f. galliae,
blue = Bavarian cluster, orange = C. f. fiber and eastern group) based
on nuclear (bars) and mitochondrial DNA (dots). All populations
except of the “green population” of C. f. albicus in eastern Germany
derive from reintroduction programmes.

 

Some time ago, Eurasian beavers (Castor fiber) had been exterminated throughout their entire palaearctic distribution range, except for a few residual populations. As the last group of Central European beavers was living east of the Inner-German border around the Elbe river, and because it had also shrunk greatly in numbers, beavers from a number of different European sources were used for the first reintroduction programmes in Germany. The attempts at reintroduction were often successful, and in some regions (e. g. in Bavaria) the beavers spread rapidly. For this reason, it was no longer possible to determine the origins of local beaver groups with certainty. This was especially true on account of the fact that in many places in Europe, reintroduction programmes relied both on animals that had already been reintroduced and on the North-American beaver, Castor canadensis.

In order to be able to reconstruct the respective regions of origin and the current population structures of local groups, tissue and fur samples from beavers have been subjected to genetic analysis by Senckenberg staff since 2009. Experiments in which barbed-wire snares were placed above the conspicuous beaver routes were successful, so that until the end of 2012 it proved possible to collect 247 beaver samples from Germany and neighbouring regions. The results show that, with just a few exceptions, the German stock comes from Eurasian beavers and the non-indigenous North-American species plays no significant role here. It also transpires that the reintroduced beaver ‘sub-species’ mix well. For instance, in Bavaria they have established a largely homogeneous reproduction unit of which the origins can only be reconstructed by investigating the mitochondrial, maternal lines. This is also true of other regions such as Switzerland and Brandenburg, where converging genetic lineages have merged with each other.

We can therefore assume that in the long term, the German beaver stocks will consist of more or less well connected, mixed groups of very varied origin. All these European residual populations are genetically similar. Furthermore, recent palaeogenetic findings indicate that it is not possible to identify clearly defined genetic subgroups (such as the Elbe beaver or the Rhone beaver), and the historical genetic record is quite complex. Therefore, apart from the difficulty of preventing it, there is little reason to regret the mixing of the stocks from a scientific point of view – as long as efforts are undertaken to prevent alien North-American beavers from spreading.

Future perspectives – a conservation genetics centre at Senckenberg

The examples involving wolves, wildcats and beavers mentioned above show how genetic investigation on wild animals using non-invasive sampling leads to a hitherto unheard of sample density. There is no other way of achieving this for rare and endangered species. For instance, without the genetic investigations on wolves, mainly through analysis of faeces samples, it would be impossible to identify individual pack members, and there would be no way of mapping the distribution dynamics in any detail. In the future, the Conservation Genetics Section will be systematically extending the scope of the genetic analyses. It offers such expertise by way of service provision to public authorities, research institutes and nature protection associations, and its own research is largely funded through these services. Therefore, in 2012, the hazel grouse (Bonasa bonasia) – acutely endangered in Hesse – as well as the common hamster (Cricetus cricetus) and the saiga antilope (Saiga tatarica) were included in the genetic monitoring.

As part of a research project sponsored by the Leibniz Society’s Senate Competition Committee, new types of genomic marker systems are being developed with the aim of making the analyses more effective, more sensitive and cheaper. The aims are to bring science and practical species conservation work in Germany closer together and, in view of the current decrease in biodiversity, to allow vital nature and species protection efforts to profit from scientific and technical progress in molecular biology.

The close links that exist between countless bodies and cooperation partners from the public sector (e. g. the Federal Agency for Nature Conservation, the Hesse Ministry for the Environment, the Hesse Forestry Administration), as well as nature protection organizations such as the Frankfurt Zoological Society, BUND, NABU and WWF, confirm our conviction that the conservation genetics centre in Germany that is being established by Senckenberg is urgently needed.

  

Author

Dr. Carsten Nowak

Dr. Carsten Nowak studied and obtained his Ph. D. at the Goethe University, Frankfurt am Main. Following a period of postdoctoral research at the University of Notre Dame, Indiana, he took over as Head of the Senckenberg Conservation Genetics Section. There, he is conducting research on aquatic invertebrates to establish the significance of genetic diversity for the survival potential of populations. He is also researching the influence of environmental factors on genetic diversity. In addition to this, wildlife genetics as an interface between science and applied species conservation is playing an increasingly important role for his section.

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