Mouse eDNA... What Next?

In late 2022, PFR Research & Operations Manager Kevin Carter waded into waterways to collect water samples, which were sent to Wellington to be tested for traces of eDNA.

eDNA is short for environmental DNA, and it refers to small traces of genetic material left behind by living organisms in the environment. A sample of soil or water which is tested for traces of DNA can reveal the species that have lived in or travelled through the area.

We were looking for mouse eDNA - in an effort to understand whether these tiny predators have gained a stealthy foothold around Oban. This is important because if they are here, and we eradicate rats and feral cats, then we could see the mouse population explode - creating a new problem for our taonga species, and for residents - something we want to avoid!

Initial results were encouraging, with no mouse DNA detected. Even though mice weren't detected with this first survey round, more work is required to provide confidence in their presence or absence in various likely locations. A key principle in science is that "the absence of evidence does not necessarily provide evidence of absence".

However, we did learn that using eDNA sampling is straightforward and easily completed, and will be a handy tool, amongst others, for our kete in future. It was also very exciting to see the range of other species detected, including native fish and insects.

You can check out the results for yourself!

Head to www.wilderlab.co.nz/explore - zoom in on Rakiura, and click on the sites to see what species were detected at each location!

Read our introduction to our Mouse eDNA research, and find more information here.