DNA to indicate relationships, movements etc.
If we are to eradicate American mink we will need to use every scrap of information about these animals that might be available. We will have to understand how far they travel, and when they travel. We will need to know about their breeding biology and behaviour, how large are their territories and where they live at different times of year. One of the most powerful tools for providing answers to these questions is in every cell of every American mink – their genetic identity, their DNA. By taking a few cells from a mink, we can potentially identify its parents and siblings, learn where it was born and find out where it has been. This is forensic science being put to use in the service of nature conservation.
To build the reference collection that will allow us to interpret American mink DNA, we routinely take a small piece of tissue from every animal caught, and every mink found dead on a road. These samples will allow us to build up a picture of the genetic diversity of mink across our region, and to look for patterns. For example, if we were to find that the American mink in north Norfolk were genetically no different from those in south Essex or west Cambridgeshire, we would infer that there is a great deal of mixing in the population. But if there are clusters of mink with different DNA profiles within our region, we could be sure that there is little or no mixing. If we take the DNA of a territorial adult female in coastal Suffolk, and then find that young animals captured in Norwich or Hatfield are her offspring, this helps us understand how far juveniles disperse from their natal area. Knowing this degree of dispersal is vital, for example, for us to plan a trapping regime that will keep our project Core Area (essentially Norfolk and Suffolk) free of immigrating American mink, or at least recognise immigration when it has occurred.