Dispersal and gene flow in lynx in Fennoscandia

Dispersal and gene flow in lynx in Fennoscandia - consequences for management

In this project we will quantify the dispersal of lynx within Sweden and between Sweden and Norway using related individuals inferred from genetic markers. W e will quantify the dispersal of lynx between Sweden/Norway and Finland/Russia as well as estimate migration rate (rate of effective dispersal thus resulting in successful transmission of genes) using a population genetic approach. We will investigate the impact of dispersal on lynx harvest rate for Sweden and Norway, using harvest models that combine vital rates, monitoring and harvest data.

Sweden and Norway share the same lynx population, with more individuals and higher management goal in Sweden. The harvest is higher in Norway because of a higher growth rate in Norway. Current harvest models of lynx for both Norway and Sweden do not consider dispersal between different management regions (the models assume immigration and emigration to be equal). Different management regimes with spatially different harvest rates can create a source-sink dynamic, where sink population is dependent on immigration from the source population.

There is no evidence of restricted gene flow between lynx in Sweden and Norway. The genetic structure is consistent with isolation by distance. But the dispersal rate within Sweden and between Sweden and Norway in not known, which is very important knowledge in a spatially structured harvest. Transboundary populations have consequences for management especially if the management regimes differ between the regions. This is a general problem for species with populations spanning across administrative units.

The genetic variation in lynx in Scandinavia is lower than in Finland and the gene flow between Scandinavia and Finland is restricted. The SEPA has pointed out lynx dispersal in Scandinavia and the gene flow between Scandinavia and Finland as important knowledge gaps, which are important for long-term viability of the lynx population in Scandinavia.

Henrik Andren, Swedish University of Agricultural Sciences

3 030 000 SEK