Developing Monitoring Programmes and Analysing Trends in Bats Populations in the Dinarics – capacity building workshop, Skradin, Croatia, 2014

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Funded by the German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety and Le Gouvernement du Grand-Duché de Luxembourg, Administration de la nature et des forêts

Patron: State Institute for Nature Protection, Croatia

Organisers: Croatian Biospeleological Society and Vincent Wildlife Trust, BatLife Partners

Supported by: Krka National Park, Geonatura Ltd., Croatian Electricity Company (Miljacka Powerplant)

The aim of the workshop was to draw together best practice in the latest inventory, monitoring and trend analysis techniques to build capacity in the region. The workshop was intended to contribute to future cooperation across the Dinaric Arc to promote long term trans-boundary bat conservation and a sustainable future for the region’s bats.

The workshop was based in the small Croatian town of Skradin on the edge of the Krka National Park and took place in early September, right after the XIIIth European Bat Research Symposium organised in Croatia. Fifteen enthusiastic participants drawn from Albania (Protection and Preservation of Natural Environment in Albania - PPNEA), Bosnia Herzegovina (Centre for Karst and Speleology, Sarajevo), Romania (Romanian Bat Protection Association), Croatia (Croatian Biospeleological Society, Geonatura Ltd), Macedonia (Macedonian Bat Research Group), Montenegro (Biology Student Association) and Serbia (Natural History Museum Belgrade, Wildlife Conservation Society “MUSTELA”) were joined by seven course tutors. The National Park kindly allowed us to take over the upper floor of their offices during the day, so we could run more formal theory or computer-based sessions before we headed off in the evening for practical fieldwork. The Ministry of Environmental and Nature Protection (Croatia) provided us with the necessary permits to catch and handle the bats.

Daniela Hamidović from State Institute of Nature Protection and Croatian Biospeleological Society and Primož Presetnik from Centre for Cartography of Fauna and Flora, Slovenia gave us a real insight into the problems of monitoring bats that use caves as their maternity roosts. Many of the caves have mixed colonies of many thousands of bats and the only way to gauge their numbers is to use infra-red video cameras in combination with the photo camera and film the clusters. The techniques used and the comprehensive monitoring protocol used in Croatia were demonstrated to the participants at the Miljacka II Cave, Krka National Park.


Catching and identifying bats in the hand was another key objective of the workshop. Here we were helped by Daniela’s team of experienced bat researchers, Marina Kipson and Norma Fressel, and Dina Kovac from Geonatura Ltd provided the necessary mist netting equipment. We spent time mist netting along the banks of the Krka River and the most numerous species we caught was the Long-fingered bat, a flag-ship species for this part of Europe. Identifying bats is always difficult but in an area of Europe with over 30 different species it was particularly tricky in Croatia. Fortunately, our participants were provided with identification keys by Primož and he took them through the whole identification process in a very logical and methodical way.

Participants learning how to handle bats.JPG 

The effective use of bat detectors was a major part of the workshop. Chris Corben, who designed the Anabat system, led sessions on using frequency division detectors and how to analyse calls from these machines. Kate Barlow from the Bat Conservation Trust led on the use of time-expansion detectors. The participants learned the theory of how the machines worked during the day and in the evening they headed out to make their own surveys of Skradin. The following morning was spent analysing the calls they had recorded the evening before.

By the end of the workshop we had built up a pretty good picture of the bat fauna of the town and discovered at least 5 new species not recorded before for the area or the Krka National Park with all new data being deposited in the State Institute for Nature Protection Database.


Using radio-telemetry is an important technique in the study of bats. We weren’t able to do any real radio-tracking during the workshop as this would have disturbed bats without gaining any real data and so we had a simulated tracking session with Anita Glover from the University of Leeds play the part of the bat. The local inhabitants of Skradin and the daily influx of visitors to the Park were a bit perplexed to see nearly 20 people with antenna and receiver hunting for her through the vegetation at the edge of the town.


Although the fieldwork is often viewed at the more fun aspect of bat work, being able to analyse the data you collect is equally important. Tom van der Meij, who works for Statistics Netherlands, walked us through the statistical analysis of monitoring data and how to determine population trends. Statistics Netherlands have developed a software packaged called TRIM, which is being used in many countries to determine populations trends. It is hoped that in time all of the monitoring data collected in the Dinaric Arc will be combined using this software to produce a biological indicator for the region.

As well as the fixed programme, we were able to fit in some impromptu talks during the workshop. Sébastien Puechmaille from Ernst-Moritz-Arndt University in Germany joined us for a few days and gave a talk on genetics and bat DNA sampling techniques and Anita Glover gave a presentation on swarming behaviour in bats. Clare Marie Mifsud from Malta was a huge help both in the field and analysing bat calls.