ACTA ZOOLOGICA BULGARICA Zoogeography and Faunistics Acta zool. bulg., 68 (4), 2016: 519-527 Research Article Contribution to the Knowledge on Amphibians and Reptiles of North-western Croatia Olga Jovanović Glavaš1, Igor Vilaj2, Boris Lauš2, Paula Dvorski2, Toni Koren2, Ana Kolarić2, Irena Grbac3 & Goran Šafarek4 1 Department of Biology, University University of Osijek, Cara Hadrijana 8/A, HR-31000 Osijek, Croatia; E-mail: [email protected] 2 Association Hyla, Lipovac I No.7, HR-10000 Zagreb, Croatia 3 Croatian Natural History Museum, Demetrova 1, HR-10000 Zagreb, Croatia 4 Society for Research and Popularization of Science Baobab, Trg kralja Krešimira 10, HR-48000 Koprivnica, Croatia Abstract: The amphibian and reptile fauna of North-western Croatia was never systematically surveyed and knowl- edge of it is incomplete. In 2008–2015, we conducted a detailed survey of the region and recorded 17 amphibian species (85% of all species in Croatia) and 13 reptile species (33% of all reptile species in Croatia). We recorded all typical and widespread species of amphibians and reptiles expected to occur the relatively well-preserved habitats in this area. Further, we also present data on some rare species such as Vipera berus and Zootoca vivipara as well as on species included in the Natura 2000 network: Triturus carnifex, T. dobrogicus, Bombina bombina, B. variegata and Emys orbicularis. The surprising species richness of the studied area, which is under high anthropogenic pressure, establishes a good foundations for further protection and management of amphibians and reptiles. Key words: Amphibia, Reptilia, species inventory, Natura 2000 Introduction Croatia is a member of the South East European 2015), the average population density for Croatia was (SEE) region and has a very important biogeo- 75.71 individuals per km2. From our study area, only graphical position. Situated between the Pannonian the Koprivnica-Križevci County has a lower-than- Plain in the north-east, bordered by the Alps in the average population density of 66.12 individuals per north-west, and connecting the Dinaric Arc with the km2; the remaining three counties have above aver- Mediterranean, its biodiversity represents a mixture age densities (Krapina-Zagorje County with 108.13, of the aforementioned regions. Its surface area is Varaždin County with 139.42 and Međimurje County only 56 590 km2 and, with 39 species of reptiles and with 156.11 individuals per km2; ANONYMOUS 2015). 20 species of amphibians, it is among the European Hence, rare natural habitats and the knowledge on countries with a high diversity of the herpetofauna species’ distribution are of great importance. (Je l i ć et al. 2009). Despite this, there are still huge gaps in the knowledge of distribution of amphibians Studies and reptiles in Croatia. One of the poorly known are- According to the Red Book of Amphibians and as, with very few published records, is North-western Reptiles of Croatia (Je l i ć et al. 2012), there are 58 Croatia, from the Slovenian border north-west from native, one introduced and two potentially present Zagreb, up to the town of Koprivnica including the species but, since the latter have never been con- confluence of the Mura and Drava Rivers. firmed, they are not included in the present article. This is the most densely populated area in According to the data compiled by Je l i ć (2014), Croatia. According to the last census (ANONYMOUS there are several published records of amphibians 519 Jovanović Glavaš O., I. Vilaj, B. Lauš, P. Dvorski, T. Koren, A. Kolarić, I. Grbac & G. Šafarek and reptiles in this area. They mention the smooth is the river dynamics, constantly shaping the envi- snake Coronella austriaca Laurenti, 1768; sand liz- ronment by continuously creating new habitats and ard Lacerta agilis Linnaeus, 1758; agile frog Rana bringing regular floods that fill depressions where dalmatina Fitzinger in Bonaparte, 1838 (Pa v l e t i ć stagnant water stays for weeks. A narrow strip very 1964); moor frog Rana arvalis Nilsson, 1842 close to the river is still in its natural state, without (KA R A M A N 1921); nose-horned viper Vipera am- significant human impact (ŠA F A RE K 2011). modytes Linnaeus, 1758; grass snake Natrix natrix Protection status (Linnaeus, 1758) (Pa v l e t i ć 1964, RÖSSLER , 1904); In the surveyed region, there are two main protected adder Vipera berus (Linnaeus, 1758) (KA R A M A N areas. These are: Nature Park Medvednica, founded 1921, VIL A J & DV ORS K I 2014, WERNER 1897). JA NE V in 1981 (ANONYMOUS 1981), which was only partially HUTINEC et al. (2013) published a popular handbook included in our study area, and Regional Park Mura- on herpetofauna in Međimurje but the data presented Drava, founded in 2011, which incorporates the area there have no scientific value. In the present work, we of Drava and Mura Rivers (ANONYMOUS 2011). In give a comprehensive overview of herpetofauna in 2012, the whole area of the Mura, Drava and Danube North-western Croatia, which is based on extensive Rivers in Croatia and Hungary was declared as a fieldwork carried out over a period of eight years. transboundary biosphere reserve (MAB), raising the importance of the region. Additionally, in 2013, 36 Materials and Methods sites from our study area were added to the National Study area ecological network, which is a part of the Natura 2000 ecological network (ANONYMOUS 2013a). Thus, This survey was carried out on the territory of four many diverse habitats and species within our study counties in North-west Croatia (Fig. 1). A great area gained legal protection. number of habitat types were examined. North- western Croatia was a territorial unit that included Sampling methods six counties: Krapina-Zagorje, Varaždin, Međimurje, Fieldwork was carried out from 2008 till 2015. In or- Koprivnica-Križevci, Zagreb County and the City of der to obtain the best results, several sampling meth- Zagreb as a separate entity till 2012 (ANONYMOUS ods were combined. Most of the data was obtained 2007). The name was taken over because it best de- by visual observation, which consisted of examin- scribes the research area. Due to the specificity of ing the area in a certain period of time and search- the City of Zagreb and Zagreb County, they were ing for different species. In all stagnant freshwater excluded from further analyses in this paper. Thus, habitats, hand-nets (eye size 1 mm) were used in or- when referring to North-western Croatia, it will only der to investigate aquatic stages of amphibians, i.e. include the remaining four counties. adults and larvae of frogs and newts. In the ponds, Geographically, the research area can be divid- lakes and other stagnant freshwater habitats, traps ed into a highland part and a lowland part. The high- for newts and for terrapins were set. Near the same land area is characterised by many hills and a several habitats, pit-fall traps and nylon fences were set for a mountains (such as Ivanščica, Strahinjščica, Macelj, shorter period and checked on a daily basis. Ravna gora and Kalnik), with the highest peak of All caught and identified animals were photo- 1060 m a.s.l. on Ivanščica Mt. The area is covered graphed and released unharmed afterwards back into with mesophyllic forests, meadows, mosaic habitats the wild at the same spot where they were found. and agricultural land (from lower to higher intensity Coordinates for each individual were recorded using of maintenance). Hills are criss-crossed with nu- a GPS device. merous smaller streams flowing from the southern While identifying species of the Pelophylax com- slopes into the Krapina River basin, reaching the plex, authors were guided by previously known data Sava River next to Zagreb City. From the northern that included three species: marsh frog Pelophylax slopes streams flow to the Bednja and Drava Rivers. ridibundus (Pallas, 1771), pool frog Pelophylax les- Forest pools and ponds are also relatively abundant sonae (Camerano, 1882) and edible frog Pelophylax there, while wetlands are relatively rare compared kl. esculentus (Linnaeus, 1758). However, in light to floodplains of the Drava and Mura Rivers. The of recent data based on DNA analysis (Je l i ć et al. lowlands are a part of the Pannonian plain, which 2015), we know today that this species complex is incorporates the alluvial plains of Drava and Mura much more perplexing, with an unexpected presence and is rich in rare and endangered habitats, such as of the Balkan water frog Pelophylax kurtmuelleri flooded forests, oxbow lakes, meanders and escarp- (Gayda, 1940), as well as a new hybrid complex in ments. The major element for this habitat diversity Croatia. Therefore, results on green frogs reported 520 Contribution to the Knowledge on Amphibians and Reptiles of North-western Croatia Table 1. List of recorded species in the study area with IUCN categories, legal status, and number of records. *SP – strictly protected Red Book Habitats Nature protection Number Family Latin name category Directive (Annex) law (Croatia)* of records Class: Amphibia Order: Caudata Ichthyosaura alpestris LC / / 31 Lissotriton vulgaris LC / / 16 Salamandridae Salamandra salamandra LC / / 61 Triturus carnifex NT II, IV SP 3 Triturus dobrogicus NT II, IV SP 2 Order: Anura Bombina bombina NT II, IV SP 23 Bombinatoridae Bombina variegata LC II, IV SP 75 Pelobatidae Pelobates fuscus DD IV SP 6 Bufotes viridis LC IV SP 12 Bufonidae Bufo bufo LC / / 151 Hylidae Hyla arborea LC IV SP 20 Pelophylax kl. esculentus LC V 100 Pelophylax lessonae