CONTRIBUTION TO THE HERPETOFAUNA OF SERBIA-DISTRIBUTION OF REPTILES IN KOSOVO AND METOHIJA PROVINCE

Kosovo and Metohija have already been recognized as regions with the highest diversity of reptiles in Serbia, where 92% (22 of 24) of existing reptile species can be found (Tomović et al., 2015a). First comprehensive contribution to herpetofauna of Kosovo and Metohija was provided by late Professor Gojko Pasuljević. In this study we present a complete dataset of distribution records for 13 most common reptile species in Kosovo and Metohija, including published and new distribution data compiled, and provide standardized 10 x 10 km UTM maps for these data. Results of this study include 1013 distribution records (278 new and 735 published data) for the following reptiles: Testudo hermanni, Ablepharus kitaibelii, Anguis fragilis, Lacerta agilis, Lacerta viridis, Podarcis muralis, Podarcis tauricus, Coronella austriaca, Dolichophis caspius, Natrix natrix, Natrix tessellata, Zamenis longissimus and Vipera ammodytes. The most widely distributed species, which occupy more than 50 UTM 10 x 10 km squares are: Podarcis muralis and Vipera ammodytes. Species with limited distribution which occupy less than 20 UTM 10 x 10 km are: Dolichophis caspius and Lacerta agilis. The largest numbers of new or confirmed literature data are recorded for: Anguis fragilis, Testudo hermanni and Vipera ammodytes. Having in mind that after 50 years, this is the first comprehensive study of the distribution of reptiles in Kosovo and Metohija exclusively, the presented faunistic data are far from being complete. Further systematic studies should provide a more complete insight into the distribution of herpetofauna of this province of Serbia.


INTRODUCTION
The  first important step preceding the studies of systematics, ecology and biogeography is the comprehensive knowledge of biodiversity of a certain region.Therefore, systematic faunistic studies are of increasing significance, especially in the regions or countries with incomplete species distribution data (Margules et al., 2002;Jelić et al., 2013;Tomović et al., 2014).Detailed distribution data are essential for identification of biodiversity "hotspots" i.e. areas with exceptional species assemblages, high levels of endemicity and/or areas under significant threats (Gaston et al., 2002).
Concerning the herpetofauna, the Balkan Peninsula is recognized as one of the richest biodiversity hotspots in Europe (Džukić & Kalezić, 2004).Being situated in the central part of the Balkans, Serbia is a very important territory for diversity of reptiles, due to the occurrence of various biogeographical phenomena: presence of the Balkan endemic species and relicts, different faunal elements, marginality of certain species' ranges and presence of peripheral populations, as well as range fragmentation (Džukić, 1995;Džukić & Kalezić, 2004).* Corresponding author: lili@bio.bg.ac.rsProvince of Kosovo and Metohija has already been identified as one of the regions with the highest reptile's diversity in Serbia, with 22 species recorded (Tomović et al., 2015a).First comprehensive contribution to herpetofauna of Kosovo and Metohija was given by Pasuljević (1968).In the following decades, faunistic papers were primarily focused on several rare (or uncommon) species with peripheral or disjunct occurrence within the territory of ex-Yugoslavia or Serbia: Algyroides nigropunctatus (Džukić, 1970;Džukić & Pasuljević, 1979), Darevskia praticola (Džukić, 1974;Pasuljević & Džukić, 1979), Cyrtodactylus kotschyi (Ajtić & Tomović, 2001).
Therefore, with this study we aim to: (i) publish a complete dataset of distribution records of 13 most common reptile species in Kosovo and Metohija, summarizing already published and new distribution data, and (ii) provide standardized 10 x 10 km UTM maps of the summarized data.

MATERIAL AND METHODS
In this study, we presented a large dataset (1013 occurrence records) of distribution of the most common species of herpetofauna in Kosovo and Metohija.
This study is based on the species' occurrence records from authors' field observations (field data) which were kindly donated by our colleagues (see Acknowledgements).The species were identified using standard herpetological literature (Arnold & Ovenden, 2002), by visual inspection of specimens from the photographs, or directly in the field.Regarding taxonomy and current nomenclature, we followed Jablonski et al. ( 2016), Sillero et al. (2014) and Uetz et al. (2017).Due to several objective reasons, the entire territory of Kosovo and Metohija (Figure 1) was not covered by faunistic research.Our dataset is still incomplete; the lack of data from certain areas does not necessarily imply the absence of species.In addition to new (field) records, we used 735 published records from the available literature.The data were classified as: (i) new field data (red-white dots), (ii) literature data (red-black dots) and (iii) existing data confirmed by field work (red dots).All records were mapped in the 10 x 10 km UTM (Universal Transverse Mercator) grid.
For each species, new records in Kosovo and Metohija (with broad locations, exact localities, toponyms, UTM and names of persons who provided data) are given in Appendix 1. Data from the literature (with broad locations, exact localities, toponyms, UTM and literature sources) are presented in Appendix 2.

DISCUSSION
Kosovo and Metohija have already been recognized as regions with the highest diversity of reptiles in Serbia, were 92% (22 of 24) of existing reptile species can be found (Tomović et al., 2015a).The only missing species are Elaphe quatuorlineta and Platyceps najadum, which occur in southern Serbia (Pčinja river valley) (Tomović et al., 2015a).
Comparison of distribution of reptiles in Kosovo and Metohija with the entire territory of Serbia reveals a similar pattern: the most common species in Serbia are widely distributed in Kosovo and Metohija as well.All these species show uniform occurrence, determined by the presence of various adequate habitats, from lowlands to high mountains, as well as from aquatic to forest habitats.The new faunistic data expand their known distribution in Kosovo and Metohija.Presence of gaps in distribution reflects rather the lack of faunistic research in particular regions, than the actual absence of the species.
The largest number of new and literature records exist for three species which distribution in Serbia has not been published BIOLOGY yet (Anguis fragilis), or which distribution included the complete territory of ex Yugoslavia: Testudo hermanni (Ljubisavljević et al., 2014) and Vipera ammodytes (Jelić et al., 2013).
According to our dataset, two reptiles show limited and, to some extent, disjunct distribution in Kosovo and Metohija: Lacerta agilis and Dolichophis caspius (Figures 3 and 4).In Serbia, Lacerta agilis inhabits areas with continental and alpine climates, and avoids moderate-continental and sub-Mediterranean climates (Urošević et al., 2015); the same distribution pattern appears in Kosovo and Metohija.Dolichophis caspius has also a very fragmented and relatively restricted range in our country (Tomović et al., 2015b).The Caspian whip snake is associated with open steppe and foreststeppe habitats (Arnold & Ovenden, 2002).The most probable reason for its current distribution pattern is the lack of suitable habitats caused by alterations of original steppes and foreststeppes into agricultural fields.It should be noted that small number of distribution records for these two species could also be the consequence of insufficient faunistic research.
As previously mentioned (Tomović et al., 2015b), in addition to five Colubrid species recorded in Kosovo and Metohija until now, some other taxa can be expected: Hierophis gemonensis, Malpolon insignitus, Telescopus fallax and Zamenis situla.These species reach their distribution limits in Macedonia (Sterijovski et al., 2014) or in Albania (Haxhiu, 1998), very close to the Serbian border.Thus, we suppose that the presence of the abovementioned snakes in Kosovo and Metohija could be confirmed in the future studies.Dinarolacerta montenegrina, endemic lizard of the Prokletije mountain massif, is known from a small number of locations in Montenegro and Albania (Ljubisavljević et al., 2016;Mizsei et al., 2017).Parts of the Prokletije Massif lie in the bordering areas of the western Metohija, therefore, this species could also be expected in this area as well (Urošević et al., 2015).
Having in mind that after 50 years, this is the first comprehensive study of the distribution of reptiles in Kosovo and Metohija exclusively, the faunistic data presented herein are far from being complete; As it can be seen from this study, many areas (e.g. in Metohija) are still insufficiently studied.Further systematic studies of both rare and common reptile species, should provide a more comprehensive insight into the distribution and diversity of herpetofauna of this province of Republic of Serbia.

Figure 1 .
Figure 1.Map of Republic of Serbia with study area -Kosovo and Metohija province (grey).