This week I have decided to write about a trip I took last year to the Nietoperek bat and nature reserve in Poland. I was very lucky to visit as my supervisors were about to establish a collaborative project and luckily for me, a pilot study was needed to investigate the feasibility of a potential DNA project.
The bunker system was built during World War II by Germany, but was never used in the war and was afterwards used by the Polish army until 1957, after which it became abandoned. The system is now home to 30,000 – 40,000 bats that come from different European countries to hibernate there during the winter. Since the importance of the site was recognised in the 1980’s, it became a protected bat reserve and was designated as a Natura 2000 site in recent years. The Vincent Wildlife Trust, a conservation group in Britain and Ireland has participated in the annual bat census in the system over the last number of years. It was during this annual census that surveyors began to notice that pine marten (Martes martes) and stone marten (Martes foina) were also to be found in the tunnel system and their paw prints were found on the walls of the tunnels, suggesting that the martens might be predating on the bat species. See Henry Schofield’s report here for further information.
To investigate this further, a collaborative project between The Vincent Wildlife Trust, Waterford Institute of Technology and Wrocław University was established. Funding for a PhD position was also awarded to John Power, who is currently using non-invasive DNA techniques to map the distribution of marten species in the tunnels. Marten scats (poo) are collected throughout the tunnels and using DNA assays, John is able to differentiate the two species.
As the tunnel system is quite a large network incorporating over 32 km, it takes a team of people to survey the system over a few days. The most recent survey took place last January during the annual bat census. I was fortunate enough to attend the marten survey there last year, April 2012 where we spent three lovely days in the area. Entering the system is an interesting experience and immediately reminded me of the film “The Hole”. It wasn’t helped that the door was locked behind us! Upon entering the system, the first realisation is just how dark the system is. With no lights on, I literally could not see my hand in front of my face. I quickly realised that my cheap head torch wasn’t going to cut it either, but thankfully, the professionals in our group were all well equipped. The winding tunnels are very interesting and the walls are covered in graffiti. There are some problems with people illegally entering the tunnels to play ‘war games’.
Even though I arrived in April to the tunnels, there were still some clusters of bats to be found roosting on the walls including some daubenton’s, natterer’s and brown long-eared bats. We were also fortunate to see some greater mouse eared bats. For a full list of the twelve bat species recorded in the system see here. Our mission however was to collect marten scats, which we found to be abundant in the system although many were old and we were unsure what the DNA quality would be like. I think we collected around 80 scats although I’m pretty sure only a portion of those were suitable for DNA analysis.
While we were on the trip we also visited a Eurasian beaver dam, something all of us Irish people were delighted to see since we don’t have any beavers in Ireland. We were also fortunate to spot an osprey at the beaver dam, and on our way back to the airport we stopped off at the the Warta River, where we were fortunate to see numerous sea eagles.