Document Type: Original Article

Authors

1 Operation Wallacea Ltd, Wallace House, Old Bolingbroke, Lincolnshire, PE23 4EZ, UK. Computational Biology and Population Genomics Group (CoBIG2), Centre for Ecology, Evolution and Environmental Changes (ce3c), Faculty of Sciences,

2 Operation Wallacea Ltd, Wallace House, Old Bolingbroke, Lincolnshire, PE23 4EZ, UK. Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA.

3 Croatian Institute for Biodiversity, Maksimirska cesta 129/5, HR10000 Zagreb, Croatia.

4 Operation Wallacea Ltd, Wallace House, Old Bolingbroke, Lincolnshire, PE23 4EZ, UK.

5 Department of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia.

6 Operation Wallacea Ltd, Wallace House, Old Bolingbroke, Lincolnshire, PE23 4EZ, UK. Aquatic and Terrestrial Ecology (ATECO), Royal Belgian Institute of Natural Sciences (RBINS), Vautierstraat 29, 1000 Brussels, Belgium. Biodiversity

Abstract

The biogeographical importance of Dalmatia, bordered by the Dinaric Alps and the Adriatic Sea, is evident through the rich biodiversity of this region and its network of protected areas. One of those areas, Krka National Park (NP), supports a wide range of natural habitats, but rapidly increasing tourism puts high pressure on its ecosystems, despite its protected status. Accurate knowledge of species and their distributions within natural places such as Krka is essential to direct and prioritize future conservation efforts. As collecting biodiversity data is time and resource-intensive, alternative ways to obtain this information are needed. One possibility is monitoring based on eco-volunteering. From June to August of 2019, an Operation Wallacea/BIOTA scientific team surveyed a section of Krka NP and its surrounding boundaries, within the vicinity of the village of Puljane, to study its butterfly richness and abundance. Pollard walks and static count surveys were conducted with the help of eco-volunteers, testing the effectiveness of gathering field data through this approach. Overall, 57 butterfly species were found throughout the study, including four new records for Krka NP. Three further new species 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 eco-volunteering initiatives and the importance of combined research efforts to study and protect the rich biodiversity and ecosystems of protected areas.

Keywords

DOI: ‎ 10.22120/jwb.2020.135022.1175

Special issue 58-67 (2020)

Challenges for Biodiversity and Conservation in the Mediterranean Region

Research Article

(http://www.wildlife-biodiversity.com/)

he value of eco-volunteer projects for biodiversity conservation: butterfly monitoring in Krka National Park (Croatia) with an updated checklist


Miguel  Simões  Nunes1,2*, Kristie Falconer1,3, Dušan Jelić4, Thomas Edward Martin1, Mladen Kučinić5, Merlijn Jocque 1,6,7

1Operation Wallacea Ltd, Wallace House, Old Bolingbroke, Lincolnshire, PE23 4EX, UK,

2Computational Biology and Population Genomics Group (CoBIG2), Centre for Ecology, Evolution and Environmental Changes (ce3c), Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016 Lisbon, Portugal,

3Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA,

4Croatian Institute for Biodiversity, Maksimirska cesta 129/5, HR10000 Zagreb, Croatia,

5Department of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia,

6Aquatic and Terrestrial Ecology (ATECO), Royal Belgian Institute of Natural Sciences (RBINS), Vautierstraat 29, 1000 Brussels, Belgium,

7Biodiversity Inventory for Conservation (BINCO), Walmersumstraat 44, 3880 Glabbeek, Belgium

‎*Email: miguel.sn.bio@gmail.com

Received: 19 August 2020 / Revised: 20 October 2020 / Accepted: 20 October 2020 / Published online: 21 October 2020. Ministry of Sciences, Research, and Technology, Arak University, Iran.

 

Abstract

The biogeographical importance of Dalmatia, bordered by the Dinaric Alps and the Adriatic Sea, is evident through the rich biodiversity of this region and its network of protected areas. One of those areas, Krka National Park (NP), supports a wide range of natural habitats, but rapidly increasing tourism puts high pressure on its ecosystems, despite its protected status. Accurate knowledge of species and their distributions within natural places such as Krka is essential to direct and prioritize future conservation efforts. As collecting biodiversity data is time and resource-intensive, alternative ways to obtain this information are needed. One possibility is monitoring based on eco-volunteering. From June to August of 2019, an Operation Wallacea/BIOTA scientific team surveyed a section of Krka NP and its surrounding boundaries, within the vicinity of the village of Puljane, to study its butterfly richness and abundance. Pollard walks and static count surveys were conducted with the help of eco-volunteers, testing the effectiveness of gathering field data through this approach. Overall, 57 butterfly species were found throughout the study, including four new records for Krka NP. Three further new species 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 eco-volunteering initiatives and the importance of combined research efforts to study and protect the rich biodiversity and ecosystems of protected areas.

 Keywords: Citizen Science, Entomology, Inventory, Lepidoptera, Protected areas

Introduction

The Mediterranean biodiversity hotspot (Myers et al. 2000) supports a significant butterfly richness, with numerous endemic species often constrained to small isolated populations (Numa et al. 2016). Croatia and especially Dalmatia - the southern region of the country bordered by the Dinaric Alps and the Mediterranean Sea - is mainly characterized by high endemism and high diversity of taxa (Williams et al. 2000, Van Swaay and Warren 2003, Jelaska et al. 2010, Koren and Laus 2013, Ćaleta et al. 2015, Ivković and Plant 2015, Ozimec et al. 2015). Located within this biogeographically important region, Krka National Park (NP) represents a natural stronghold for many species, with its extensive areas of relatively undisturbed ecosystems (Fig. 1). However, Croatian National Parks have experienced a sharp increase in tourism in recent years (Albolino 2014), with detrimental effects being noted on some of the more popular spots such as Plitvice NP (Ružić and Šutić 2014, Vurnek et al. 2018). With rapidly increasing urbanization rates, these environmental challenges put substantial pressure on natural ecosystems, increasing the need to change management plans and protect biodiversity. Therefore, to secure optimal decision making and prioritize conservation efforts, assembling accurate data on both species’ presence and their distribution inside these protected areas is vital.

 

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.

 

High-resolution data collection tends to be costly in both time and money, with detailed surveys requiring longer study times and being thus limited by budgetary and logistical constraints. On the other hand, an increasingly common approach to data collection is through eco-volunteer initiatives (Silvertown 2009). Although not all taxa are equally suitable for citizen scientist-driven inventory projects (Dickinson et al. 2012), butterflies are often well-suited due to their high dispersal capacity, conspicuous nature, relatively large population sizes (at least for most species), and relative ease of identification (for most species) (Dennis et al. 2017). Additionally, butterflies are also good bioindicators of ecosystem quality, given their high sensitivity to small changes in environmental conditions (Van Swaay et al. 2008). As such, monitoring data from this group can, to some extent, be used to determine further optimal niche conditions and demographic trends in more cryptic taxa (Thomas 2005).

The scientific knowledge of the Croatian Lepidoptera has dramatically improved during the last decade, with some regions of the country becoming very well studied (Lorković 2009, Koren et al. 2011, 2015a, 2015b, 2015c, 2018, 2019, Mihoci et al. 2011, Tvrtković et al. 2012, Koren and Laus 2013, Verovnik et al. 2015). Consequently, the first checklist of Croatian butterflies was published in 2011, listing 195 species (Šašić and Mihoci 2011), and the first butterfly checklist for Krka NP was published in 2017 (Kučinić et al. 2017). However, further fieldwork is still necessary to gather accurate knowledge on the true richness of Dalmatia’s butterfly communities.

In this work, we evaluated the value of a large scientist-coordinated eco-volunteer project in Krka NP and the surrounding area, collecting butterfly diversity data with transect based and opportunistic surveys while also assembling an updated butterfly checklist for the park.


Material and methods

Study site

Krka NP is a 142 km2 protected area located in the Dalmatian region of Croatia, in the foothills of the south-western Dinaric mountains (Beran 2016, Ivković and Pont 2016), with underlying geology dominated by quaternary karstic limestones (Ivković and Pont 2016). It was founded in 1985 to protect a 50 km stretch of the Krka River between the towns of Knin and Skradin, giving the park a relatively linear shape, which follows the course of the river and its gorge (Beran 2016). The area possesses a hot-summer Mediterranean climate (Csa on the Köppen-Geiger system, Peel et al. 2007) with temperatures at Knin averaging 23ºC in July and 5ºC in January (Krka National Park Authority 2020). Precipitation averages 1078 mm per year, with most falling between October and February (Krka National Park Authority 2020).

Survey methods

Between June and August 2019, an Operation Wallacea/BIOTA lepidopterist team surveyed the north-eastern region of Krka NP and its exterior boundaries, in the vicinity of the village of Puljane, to study the butterfly richness and abundance of this area (Fig. 1). To collect standardized data, six transects were set up for Pollard walks (Pollard and Yates 1993) which covered juniper grasslands, burnt grasslands, rocky valley slopes, mixed Mediterranean juniper-oak scrub habitats, and riverine forests (Table 1). Additionally, 10-minute static counts (with a radius of 20 meters) were added at specific locations on these transects. Surveys were carried out five days per week, during which Pollard walks conducted on the transects, with the observers stopping at the defined intervals for the respective butterfly static counts.

Throughout the study, almost two hundred eco-volunteers helped scientists gather field data, divided into groups of 5-10 volunteers per day. All eco-volunteers (high school students aged 16-18 and university students aged 20+, with the former being often accompanied by teachers) were briefed on survey methods and species before helping a team of two lepidopterists to collect and count butterflies on the Pollard walks and static counts.

On both surveys, eco-volunteers helped to catch butterflies with seine nets (diameter 30 cm), and the coordinating scientist supervised species identification in the field. To further guarantee the data's reliability, a picture of each butterfly caught was taken and stored in a supplementary photographic database. Butterfly records from formal surveys were compiled into a single database, while an additional database of opportunistic observations was also assembled. Opportunistic observations occurred whenever formal surveys were not being conducted, either on the transects or in other park sections. All records were aggregated when assembling the full list of butterfly species found throughout the whole study and the transects where each species was encountered.

 

Table 1. Summary information for the transects used in the 2019 Operation Wallacea/BIOTA butterfly surveys in Krka National Park, Croatia.

Transect number

Habitat represented

Length (m)

Coordinates

Static counts per transect

1

Juniper grassland and burnt grassland

2600

Start: 43.98832, 16.04937;

End: 43.994172, 16.060951;

7

2

Juniper grassland

350

Start: 44.00583, 16.05732;

End: 44.00671, 16.05561;

2

3

Riverine forest

900

Start: 44.00676, 16.05548;

End: 44.01041, 16.0602;

5

4

Rocky valley slope

1000

Start: 43.97719, 16.03329;

End: 43.98328, 16.03175;

3

5

Riverine forest

1800

Start: 43.98254, 16.02773;

End: 43.99021, 16.017157;

5

6

Mixed Mediterranean oak-juniper scrub habitat

1540

Start: 43.973416, 16.050413;

End: 43.974991, 16.049849;

5

 

Results

By the end of the season, a total of 1362 butterfly observations were entered in the database, obtained from 61 transect Pollard Walks and 149 static counts, which together comprised over 92 hours of survey time. From the previous list of eighty-one butterfly species given for the whole Krka NP (Kučinić et al. 2017), fifty of these were also found during our field work, both inside and outside the park’s border. Furthermore, we found seven other species not included in Kučinić et al. (2017), four of these inside the park’s borders and thus new species for Krka NP: Fabriciana niobe (Linnaeus 1758 - Nymphalidae), Polyommatus escheri (Hübner 1823 - Lycaenidae), Satyrium ilicis (Esper 1779 - Lycaenidae) and Spialia orbifer (Hübner 1823 - Hesperiidae). The remaining three were found just outside the border of the park, two in the small town of Bračići (Puljane) and the other within a transect: Pyrgus armoricanus (Oberthür 1910 - Hesperiidae), Iolana iolas (Ochsenheimer 1816 - Lycaenidae) and Tarucus balkanicus (Freyer 1845 - Lycaenidae), respectively (Fig. 2). An updated butterfly species list for Krka NP is presented in Table S1, which also specifies the species found in the course of this project, alongside where they were found. Additionally, graphics are presented in Supplementary Material for all species encountered, showing when and where these were spotted throughout the season (Fig. S1-S5).

From the updated species list, and including the potentially new species found just outside the Park borders (Table S1), six taxa have a Near Threatened conservation status on the Red List of European butterflies (Van Swaay et al. 2010, IUCN 2020): Thymelicus acteon (Rottemburg 1775), Iolana iolas, Polyommatus dorylas (Denis and Schiffermüller 1775), Pseudophilotes vicrama (Hemming 1929), Chazara briseis (Linnaeus 1764) and Hipparchia statillinus (Hufnagel 1766). Additionally, seven species from the same list have a Near Threatened status within Croatia, according to the Red List of Croatian butterflies (Šašić et al. 2015), one of them shared with the European Red List: Glaucopsyche alexis (Poda, 1761), Pseudophilotes vicrama, Scolitantides orion (Pallas 1771), Euphydryas aurinia (Rottemburg 1775), Proterebia phegea dalmata (Godart 1824), Papilio machaon (Linnaeus 1758) and Zerynthia polyxena (Denis and Schiffermüller 1775).

 

Figure 2.  Photographs of the four new species discovered for Krka National Park in the course of the 2019 fieldwork (A-F) and the three potential new species found just outside the Park (G-I): A-C) Polyommatus escheri; D) Fabriciana niobe; E) Satyrium ilicis; F) Spialia orbifer; G) Iolana iolas; H) Tarucus balkanicus; I) Pyrgus armoricanus.

 
Discussion

This first trial of scientist-coordinated eco-volunteer surveys in Krka NP has shown the potential value of this approach for biodiversity data collection and biodiversity monitoring. The sampling effort throughout the study was greatly improved with the further collaboration of eco-volunteers, increasing the human capacity for collecting and counting butterflies, while the supervision of trained lepidopterists allowed for a high level of data quality control.

Overall, the fieldwork has enabled the assemblage of a consistent record database with fifty-seven species and the detection of four new butterfly species for Krka NP, as well as another three new ones just outside the park’s border. A significant proportion of the butterfly species previously recorded from the Park (Kučinić et al. 2017) was not encountered in this study due to a probable mismatch between their flight season and our own field work (Table S1). The different timing in which each species was observed throughout the field season (see Supplementary Figures S1-S5) highlights the diversity of species flying within this National Park in different time periods and how the park is supporting butterfly biodiversity throughout most of the year. The establishment of transects covering different habitats and ecosystems facilitated the detection of a higher diversity of species, highlighting the importance of stratified sampling strategies. Moreover, small microhabitats that were included by chance in some transect paths often yielded important species records, as with the case of a small floodplain meadow on one of the riverine forest transects (T5), which yielded several Lycaenidae and Hesperiidae species not recorded elsewhere.

Of the new species recorded for the park, three had a previously known widespread distribution and their presence in Krka is not surprising: Fabriciana niobe, Satyrium ilicis and Spialia orbifer (Tolman and Lewington 2008, Lorković 2009, Koren et al. 2011, 2015a, 2015b, 2015c, 2018, 2019, Mihoci et al. 2011, Tvrtković et al. 2012, Koren and Laus 2013, Verovnik et al. 2015, Leraut 2016). The fourth species, Polyommatus escheri, has a theoretical distribution that includes the spatial area of the park but is likely at the limit of its overall range here (Tolman and Lewington 2008, Koren et al. 2011, 2015a, 2015c, 2018, 2019, Mihoci et al. 2011, Tvrtković et al. 2012, 2015, Verovnik et al. 2015, Leraut 2016). From the three potential new species found just outside the park’s boundaries, Pyrgus armoricanus and Iolana iolas in the village of Puljane and Tarucus balkanicus in T1, the first two have a widespread theoretical distribution that covers the area of the park while the second is already approaching the limit of its range in Krka (Tolman and Lewington 2008, Lorković 2009, Koren and Ladavac 2010, Koren et al. 2011, 2013, 2015a, 2015b, 2015c, 2017, 2018, 2019, Mihoci et al. 2011, Tvrtković et al. 2012, 2015, Koren and Laus 2013, Koren and Letić 2014, Verovnik et al. 2015, Leraut 2016). We believe that these three species are likely also present inside Krka NP, as P. armoricanus and I. iolas were respectively found less than 400 m and 700 m away from its boundaries and Tarucus balkanicus less than 2 km away, with the hostplant of the latter, Paliurus spina-christi P. Mill. (Rhamnaceae), being known to occur within the Park (Vuković et al. 2017, Šegota et al. 2019). Nonetheless, the presence of these species within Krka NP still requires confirmation from additional future surveys inside its borders. Similarly, a further species of grayling, Hipparchia fagi (Scopoli 1763), is potentially present within Krka NP and might have been encountered in the course of our surveys. It was tentatively identified by small wing features that possibly distinguish it from the phenotypically similar Hipparchia syriaca (Staudinger 1871). However, as the definitive distinguishable feature between them is on the morphology of their genitalia (Lorković 1976; Jutzeler et al. 2009), and as this was not inspected, we decided not to include H. fagi in our checklist.

Overall, the results obtained in this study highlight the effectiveness of eco-volunteer surveys for yielding important data on butterfly communities, especially when these volunteers are supervised by trained lepidopterists. These results also indicate the value of a continuous scientific research effort inside protected areas such as Krka, as well as the importance of actively working and collaborating with National Park authorities for the protection of their native fauna and ecosystems. The fact that Krka NP shelters several Near Threatened butterfly species, either at the European or National level, reinforces the role of this park to impose strict measures for their protection, along with the other non-threatened species. Ultimately, these research efforts represent the bridge for future conservation plans, aiming to preserve the species’ populations within the natural strongholds imposed by the Parks, and completing them with the help of eco-volunteers might be the key to speed up this process. Indeed, a highly important outcome of eco-volunteer studies is their outreach, as they provide young people from a range of different backgrounds with the opportunity to gain first-hand experience with survey work relating to the conservation of both wildlife and ecosystems while also inspiring them to step forward and stand for their protection.

Acknowledgments

This project was supported by Operation Wallacea and BIOTA. We thank the many Operation Wallacea volunteers who assisted with data collection. We are also grateful to all the additional Operation Wallacea/BIOTA staff working in Krka NP during the field work period of this study for their help with some of the surveys and opportunistic walks. We extend a special thank you to David Robin Jackson, Alessio Ferrari, and Mia Jakopović for their continued interest and support in the field, as well as to Matea Jarak and Bernice Hyett for their everyday help with survey’s logistics. We also give particular thanks to the lepidopterist Eduardo Marabuto for his assistance with confirming some species’ identifications, and for the specific identification of Polyommatus escheri, as well as Dr. Toni Koren for his help confirming the identification of the species Pyrgus armoricanus. Finally, we want to thank the four anonymous reviewers who helped improve the paper, and we extend thanks to the Croatian Ministry of Environment and Energy for issuing research permits supporting this project.

References

Albolino O. 2014. The tourism in Croatia: Politics, Projects and Environmental sustainability. Bollettino Della Societa Geografica Italiana 8(7): 413–433.

Beran L. 2016. A contribution to knowledge of freshwater molluscs (mollusca) of the Krka river in the Krka national park (Croatia). Natura Croatica 25: 295–304.

Ćaleta M., Buj I., Mrakovčić M., Mustafić P., Zanella D., Marčić Z., Duplić A., Mihinjač T., Katavić I. 2015. Endemic Fishes of Croatia. Zagreb: Croatian Environment Agency. pp 121.

Dennis E.B., Morgan B.J.T., Brereton T.M., Roy D.B., Fox R. 2017. Using citizen science butterfly counts to predict species population trends. Conservation Biology 31(6): 1350–1361.

Dickinson J.L., Shirk J., Bonter D., Bonney R., Crain R.L., Martin J., Phillips T.,  Purcell K. 2012. The current state of citizen science as a tool for ecological research and public engagement. Frontiers in Ecology and the Environment 10: 291–297.

IUCN. 2020. The IUCN Red List of Threatened Species. Version 2020-1. Accessed 01/06/2020 from https://www.iucnredlist.org/

Ivković M., Plant A. 2015. Aquatic insects in the Dinarides: identifying hotspots of endemism and species richness shaped by geological and hydrological history using Empididae ( Diptera ). Insect Conservation and Diversity 8(4): 302–312.

Ivković M., Pont A.C. 2016. Long-time emergence patterns of Limnophora species (Diptera, Muscidae) in specific karst habitats: tufa barriers. Limnologica 61: 29–35.

Jelaska S.D., Nikolić T., Jelaska L.S., Kušan V., Peternel H., Gužvica G., Major Z. 2010. Terrestrial biodiversity analyses in Dalmatia (Croatia): a complementary approach using diversity and rarity. Environmental Management 45: 616–625.

Jutzeler D., Lafranchis T., Verovnik R., Volpe G. 2009. Confirmation du rang spécifique d’Hipparchia syriaca Staudinger (1871) par élevage et examen en Grèce du principe d’exclusion d’H. fagi et syriaca que Lorković (1976) avait découvert en Dalmatie (Lepidoptera: Nymphalidae, Satyrinae). Entomologica Romanica 14: 5–12.

Koren T., Ladavac L. 2010. Butterfly fauna (Lepidoptera: Hesperioidea & Papilionoidea) of Central Istria (Croatia). Natura Croatica: Periodicum Musei Historiae Naturalis Croatici 19 (2): 369–380.

Koren T., Bjelic M., Bozinovska E., Štih A., Buric I. 2011. Contribution to the knowledge of butterfly fauna (Lepidoptera: Rhopalocera) of Zrmanja river region, Croatia. Acta Entomologica Slovenica 19: 155–168.

Koren T., Zadravec M., Štih A., Hlavati D. 2013 Butterfly fauna (Hesperoidea & Papilionoidea) of a rural part of Zagreb City, Croatia. Natura Croatica: Periodicum Musei Historiae Naturalis Croatici 22 (2): 253–264.

Koren T., Črne M., Withrington D.K.J. 2015a. Butterflies (Lepidoptera: Papilionoidea, Hesperioidea) of the Adriatic islands of Cres and Lošinj, Croatia. Entomologist’s Gazette 66: 81–94.

Koren T., Vukotić K., Verovnik R. 2015b. Butterflies (Lepidoptera: Papilionoidea & Hesperioidea) of the Croatian islands: new surveys of Vir, Murter, Čiovo and Šolta. Entomologist’s Gazette 66: 187–197.

Koren T., Črne M., Pavliha G., Trkov D. 2015c. Mountain Poštak, a new hotspot for the Lepidoptera of Croatia (Lepidoptera: Rhopalocera). SHILAP Revista de Lepidopterologia 43: 145–155.

Koren T., Lauš B., Šašić M., Mihoci I., Štih A., Bralić P., Gomboc S. 2017. Contribution to the knowledge of the butterfly fauna (Lepidoptera: Papilionoidea) of Hrvatsko Zagorje, Croatia. Natura Croatica: Periodicum Musei Historiae Naturalis Croatici 26 (2): 167–196.

Koren, T., Whithrington, D., Štih, A., Gros, P. 2018. The butterflies of the Istria county (Istria, Croatia): A review of their distribution, status and conservation requirements (Lepidoptera: Rhopalocera). Gortania. Botanica, Zoologia 40: 95–114.

Koren, T., Burić, I., Glavan, G., Verovnik, R.2019. Contribution to the knowledge of the butterfly fauna (Lepidoptera: Papilionoidea) of Mt Kozjak, Split, Croatia. Natura Croatica: Periodicum Musei Historiae Naturalis Croatici 28 (1): 21–34.

Koren T., Laus B. 2013. Dinara Massif - a new hotspot for the butterfly (Papilionoidea) diversity of the Dinaric Arc. Nota Lepidopterologica 36(2): 109–126.

Koren T., Letić G. 2014. Butterfly fauna (Lepidoptera: Rhopalocera) of Donji Emovci, Požega, Croatia. Natura Sloveniae 16 (2): 5–16.

Krka National Park Authority. 2020. Krka National Park Climate. Accessed 13/07/20 from http://www.np-krka.hr/stranice/climate/89/en.html

Kučinić M., Mihoci I., Delić A., Vajdić M., Marguš D. 2017. Faunističke značajke danjih leptira (Lepidoptera, Rhoplacera)  Nacionalnog parka "Krka" // Zbornik radova: Znanstveno-stručni skup -Vizija i izazovi upravljanja zaštićenim područjima prirode u Republici Hrvatskoj - Aktivna zaštita i održivo upravljanje u Nacionalnom parku "Krka" / Marguš, Drago (ur.). Šibenik: Javna ustanova "Nacionalni park Krka", 2017. str. 269–292.  

Leraut P. 2016. Butterflies of Europe and neighbouring regions. NAP Editions: Verrières-le-Buisson, France. Bulletin of Insectology 71 (2): pp. 1116.

Lorković Z. 1976. Taxonomische, ökologische und chorologische Beziehungen zwischen Hipparchia fagi scop., H. syriaca stgr. und H. alcyone D. & S. (Lepidopt. Satyridae). Acta Entomologica Jugoslavica 12: 11–33.

Lorković Z. 2009. The Rhopalocera fauna of Croatia with special respect to the fauna of Plitvice Lakes. Entomologia Croatica 13(1): 15–78.

Mihoci I., Hršak V., Kučinić M., Stanković V.M., Delić A., Tvrtković N. 2011. Butterfly diversity and biogeography on the Croatian karst mountain Biokovo: Vertical distribution and preference for altitude and aspect? European Journal of Entomology 108: 623–633.

Myers N., Mittermeier R.A., Mittermeier C.G., da Fonseca G.A.B., Kent J. 2000. Biodiversity hotspots for conservation priorities. Nature 403: 853–858.

Numa C., Van Swaay C., Wynhoff I., Wiemers M., Barrios V., Allen D., Sayer C., Munguira M.L., Balletto E., Benyamini D., Beshkov S., Bonelli S., Caruana R.,  Dapporto L., Franeta F., Garcia-Pereira P., Karaçetin E., Katbeh-Bader A., Maes D., Micevski N., Miller R., Monteiro E., Moulai R., Nieto A., Pamperis L., Pe’er G., Power A., Šašic´ M., Thompson K., Tzirkalli E., Verovnik R., Warrenand M., Welch H. 2016. The status and distribution of Mediterranean butterflies. IUCN Centre for Mediterranean Cooperation: Malaga, Spain.

Ozimec R., Kontić J., Maletić E., Matotan Z., Strikić F. 2015. Traditional varieties and breeds of Dalmatia. United Nations Development Programme.

Peel M.C., Finlayson B.L., Mcmahon T.A. 2007. Updated world map of the Köppen-Geiger climate classification. Hydrology and Earth System Sciences Discussions 4: 439–473.

Pollard E., Yates T.J. 1993. Monitoring butterflies for ecology and conservation: the British butterfly monitoring scheme. Springer: London.

Ružić V., Šutić B. 2014. Ecological risks of expansive tourist developement in protected areas – Case Study: Plitvice Lakes National Park. Collegium Antropologicum 38: 241–248.

Šašić M., Mihoci I. 2011. Annotated checklist of Croatian butterflies with vernacular names. Natura Croatica 20(2): 425–436.

Šašić M., Mihoci I., Kučinić M. 2015. Crvena knjiga danjih leptira Hrvatske. Ministarstvo zaštite okoliša i prirode, Državni zavod za zaštitu prirode, Hrvatski prirodoslovni muzeju: Zagreb.

Šegota V., Hršak V., Kovačić S. 2019. Rare and threatened Damasonium polyspermum Coss. (Alismataceae) discovered in Krka National park. Glasnik Hrvatskog botaničkog društva 7(1): 27-32.

Silvertown J. 2009. A new dawn for citizen science. Trends in Ecology & Evolution 24: 467–471.

Thomas J.A. 2005. Monitoring change in the abundance and distribution of insects using butterflies and other indicator groups. Philosophical Transactions of the Royal Society B: Biological Sciences 360: 339–357.

Tolman T., Lewington R. 2008. Collins Butterfly Guide: The most complete guide to the Butterflies of Britain and Europe. HarperCollins: London.

Tvrtković N., Šašić M., Mihoci I., Vuković M., Bjelić M. 2012. Review of the butterfly fauna (Hesperioidea & Papilionoidea) of the Dinara mountain range. Natura Croatica: Periodicum Musei Historiae Naturalis Croatici 21(2): 471–481.

Tvrtković N., Verovnik R., Lovrenčić L., Vuković M., Šašić M. 2015. New contributions to the butterfly fauna of Mt Velebit and the neighbouring area of Lika (Croatia). Natura Croatica: Periodicum Musei Historiae Naturalis Croatici 24(2): 281–292.

Van Swaay C., Van Strien A., Julliard R., Schweiger O., Brereton T., Heliölä J., Kuussaari M., Roy D., Stefanescu C., Warren M., Settele J. 2008. Developing a methodology for a European Butterfly Climate Change Indicator. Report VS2008.040, De Vlinderstichting, Wageningen.

Van Swaay C., Cuttelod A., Collins S., Maes D., Munguira M.L., Šašić M., Settele J., Verovnik R., Verstrael T., Warren M., Wiemers M., Wynhoff I. 2010. European Red List of Butterflies. Publications Office of the European Union: Luxembourg.

Van Swaay C., Warren M. 2003. Prime butterfly areas in Europe - Priority sites for conservation. National Reference Centre for Agriculture, Nature and Fisheries, Ministry of Agriculture, Nature Management and Fisheries: The Netherlands.

Verovnik R., Koren T., Glavan G. 2015. Contribution to the knowledge of the butterfly and skipper fauna of northern Dalmatia mainland. Natura Croatica 24(2): 265–280.

Vuković N., Šegota V., Brana S. 2017. Data deficient Sternbergia colchiciflora Waldst. & Kit. (Amaryllidaceae) in Croatian flora - Removing the veil of mist. Natura Croatica 26(2): 261–269.

Vurnek M., Brozinčević A., Čulinović K., Novosel A. 2018. Challenges in the Management of Plitvice Lakes National Park, Republic of Croatia. In: M.N. Suratman (Ed) National Parks: Management and Conservation. Intech Open: London. pp. 55–72.

Williams P., Humphries C., Araújo M., Lampinen R., Hagemeijer W., Gasc J., Mitchell-Jones T. 2000. Endemism and important areas for representing European biodiversity: a preliminary exploration of atlas data for plants and terrestrial vertebrates.  Belgian Journal of Entomology 2: 21–46.