DOI: 10.22120/jwb.2020.135022.1175 Special issue 58-67 (2020) Challenges for Biodiversity and Conservation in the Mediterranean Region (http://www.wildlife-biodiversity.com/) Research Article The value of eco-volunteer projects for biodiversity conservation: butterfly monitoring in Krka National Park (Croatia) with an updated checklist Miguel Simões Nunes1,2*, Kristie Abstract Falconer1,3, Dušan Jelić4, Thomas The biogeographical importance of Dalmatia, Edward Martin1, Mladen Kučinić5, bordered by the Dinaric Alps and the Adriatic Merlijn Jocque 1,6,7 Sea, is evident through the rich biodiversity of this region and its network of protected areas. 1Operation Wallacea Ltd, Wallace House, Old One of those areas, Krka National Park (NP), Bolingbroke, Lincolnshire, PE23 4EX, UK, supports a wide range of natural habitats, but 2 Computational Biology and Population rapidly increasing tourism puts high pressure on 2 Genomics Group (CoBIG ), Centre for Ecology, its ecosystems, despite its protected status. Evolution and Environmental Changes (ce3c), Accurate knowledge of species and their Faculty of Sciences, University of Lisbon, distributions within natural places such as Krka Campo Grande, 1749-016 Lisbon, Portugal, is essential to direct and prioritize future 3Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ conservation efforts. As collecting biodiversity 08544, USA, data is time and resource-intensive, alternative 4Croatian Institute for Biodiversity, ways to obtain this information are needed. One Maksimirska cesta 129/5, HR10000 Zagreb, possibility is monitoring based on eco- Croatia, volunteering. From June to August of 2019, an 5Department of Biology, Faculty of Science, Operation Wallacea/BIOTA scientific team University of Zagreb, Rooseveltov trg 6, 10000 surveyed a section of Krka NP and its Zagreb, Croatia, surrounding boundaries, within the vicinity of 6 Aquatic and Terrestrial Ecology (ATECO), the village of Puljane, to study its butterfly Royal Belgian Institute of Natural Sciences richness and abundance. Pollard walks and static (RBINS), Vautierstraat 29, 1000 Brussels, count surveys were conducted with the help of Belgium, eco-volunteers, testing the effectiveness of 7Biodiversity Inventory for Conservation (BINCO), Walmersumstraat 44, 3880 Glabbeek, gathering field data through this approach. Belgium Overall, 57 butterfly species were found *Email: [email protected] throughout the study, including four new Received: 19 August 2020 / Revised: 20 October 2020 / Accepted: records for Krka NP. Three further new species 20 October 2020 / Published online: 21 October 2020. Ministry of Sciences, Research, and Technology, Arak University, Iran. for the park were detected close to its boundaries and are also expected to occur within its borders. Here, we present an updated butterfly checklist for Krka NP, highlighting the positive impact of 59 | Journal of Wildlife and Biodiversity 4 (Special issue): 58-67 (2020) eco-volunteering initiatives and the importance Ozimec et al. 2015). Located within this of combined research efforts to study and biogeographically important region, Krka protect the rich biodiversity and ecosystems of National Park (NP) represents a natural protected areas. stronghold for many species, with its extensive areas of relatively undisturbed ecosystems (Fig. Keywords: Citizen Science, Entomology, 1). However, Croatian National Parks have Inventory, Lepidoptera, Protected areas experienced a sharp increase in tourism in Introduction recent years (Albolino 2014), with detrimental effects being noted on some of the more popular The Mediterranean biodiversity hotspot (Myers spots such as Plitvice NP (Ružić and Šutić et al. 2000) supports a significant butterfly 2014, Vurnek et al. 2018). With rapidly richness, with numerous endemic species often increasing urbanization rates, these constrained to small isolated populations environmental challenges put substantial (Numa et al. 2016). Croatia and especially pressure on natural ecosystems, increasing the Dalmatia - the southern region of the country need to change management plans and protect bordered by the Dinaric Alps and the biodiversity. Therefore, to secure optimal Mediterranean Sea - is mainly characterized by decision making and prioritize conservation high endemism and high diversity of taxa efforts, assembling accurate data on both (Williams et al. 2000, Van Swaay and Warren species’ presence and their distribution inside 2003, Jelaska et al. 2010, Koren and Laus 2013, these protected areas is vital. Ćaleta et al. 2015, Ivković and Plant 2015, Figure 1. Map showing A) Location of Krka National Park within Croatia; B) Location of Puljane within Krka NP; C) Location of transects nearby Puljane, both inside Krka NP and on its surrounding boundaries. A pale green line indicates the Park border. The yellow star represents the location of Bračići town within Puljane. 60| Journal of Wildlife and Biodiversity 4 (Special issue): 58-67 (2020) Material and methods High-resolution data collection tends to be Study site costly in both time and money, with detailed Krka NP is a 142 km2 protected area located in surveys requiring longer study times and being the Dalmatian region of Croatia, in the foothills thus limited by budgetary and logistical of the south-western Dinaric mountains (Beran constraints. On the other hand, an increasingly 2016, Ivković and Pont 2016), with underlying common approach to data collection is through geology dominated by quaternary karstic eco-volunteer initiatives (Silvertown 2009). limestones (Ivković and Pont 2016). It was Although not all taxa are equally suitable for founded in 1985 to protect a 50 km stretch of citizen scientist-driven inventory projects the Krka River between the towns of Knin and (Dickinson et al. 2012), butterflies are often Skradin, giving the park a relatively linear well-suited due to their high dispersal capacity, shape, which follows the course of the river and conspicuous nature, relatively large population its gorge (Beran 2016). The area possesses a sizes (at least for most species), and relative hot-summer Mediterranean climate (Csa on the ease of identification (for most species) (Dennis Köppen-Geiger system, Peel et al. 2007) with et al. 2017). Additionally, butterflies are also temperatures at Knin averaging 23ºC in July good bioindicators of ecosystem quality, given and 5ºC in January (Krka National Park their high sensitivity to small changes in Authority 2020). Precipitation averages 1078 environmental conditions (Van Swaay et al. mm per year, with most falling between 2008). As such, monitoring data from this October and February (Krka National Park group can, to some extent, be used to determine Authority 2020). further optimal niche conditions and demographic trends in more cryptic taxa Survey methods (Thomas 2005). Between June and August 2019, an Operation The scientific knowledge of the Croatian Wallacea/BIOTA lepidopterist team surveyed Lepidoptera has dramatically improved during the north-eastern region of Krka NP and its the last decade, with some regions of the exterior boundaries, in the vicinity of the village country becoming very well studied (Lorković of Puljane, to study the butterfly richness and 2009, Koren et al. 2011, 2015a, 2015b, 2015c, abundance of this area (Fig. 1). To collect 2018, 2019, Mihoci et al. 2011, Tvrtković et al. standardized data, six transects were set up for 2012, Koren and Laus 2013, Verovnik et al. Pollard walks (Pollard and Yates 1993) which 2015). Consequently, the first checklist of covered juniper grasslands, burnt grasslands, Croatian butterflies was published in 2011, rocky valley slopes, mixed Mediterranean listing 195 species (Šašić and Mihoci 2011), juniper-oak scrub habitats, and riverine forests and the first butterfly checklist for Krka NP was (Table 1). Additionally, 10-minute static counts published in 2017 (Kučinić et al. 2017). (with a radius of 20 meters) were added at However, further fieldwork is still necessary to specific locations on these transects. Surveys gather accurate knowledge on the true richness were carried out five days per week, during of Dalmatia’s butterfly communities. which Pollard walks conducted on the transects, In this work, we evaluated the value of a large with the observers stopping at the defined scientist-coordinated eco-volunteer project in intervals for the respective butterfly static Krka NP and the surrounding area, collecting counts. butterfly diversity data with transect based and Throughout the study, almost two hundred eco- opportunistic surveys while also assembling an volunteers helped scientists gather field data, updated butterfly checklist for the park. divided into groups of 5-10 volunteers per day. All eco-volunteers (high school students aged 16-18 and university students aged 20+, with 61 | Journal of Wildlife and Biodiversity 4 (Special issue): 58-67 (2020) the former being often accompanied by photographic database. Butterfly records from teachers) were briefed on survey methods and formal surveys were compiled into a single species before helping a team of two database, while an additional database of lepidopterists to collect and count butterflies on opportunistic observations was also assembled. the Pollard walks and static counts. Opportunistic observations occurred whenever On both surveys, eco-volunteers helped to catch formal surveys were not being conducted, butterflies with seine nets (diameter 30 cm), and either on the transects