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The first overview of the amphibians and reptiles of Dugi Otok Island, Northern Dalmatia, is presented, based on the published data and new records collected during the last twenty years. A total of 15 species are present on the island, of which only one was not recorded on our surveys. In comparison to other islands of Northern Dalmatia, Dugi Otok is the second most diverse island in terms of herpetofauna, just after Pag Island. The main threats to the amphibians and reptiles on the island are the disappearance and degradation of aquatic habitats, the abandonment and succession of traditional agricultural fields and olive groves and the increasing presence of several invasive species.
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Distribution and conservation status of the herpetofauna
of Dugi Otok Island, Croatia
Bruno Schmidt111,2, Boris Lauš1, Ana Štih11
1 Association Hyla, Lipovac I no. 7, HR-10000, Zagreb, Croatia
2 Biology Students Association – BIUS, Rooseveltov trg 6, HR-10000, Zagreb, Croatia
http://zoobank.org/AFB54FFF-730D-426C-A90F-016D26A40983
 ()

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Abstract






Key Words

Introduction

      -

       





Island characteristics

-
       
        -
2

           
      
     



        -


      
       
      

-
     

  
-

Herpetozoa 33: 191–205 (2020)
DOI 10.3897/herpetozoa.33.e53525
Copyright Bruno Schmidt et al. This is an open access article distributed under the terms of the Creative Commons Attribution Li-
cense (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and
source are credited.
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Bruno Schmidt et al.: Herpetofauna of Dugi Otok island, Croatia192
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
-
     -


     

-


     


-
     -

      


 -
     
     -
-


       

      
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
   
  

  -
     
 
   -
  



-

History of herpetological exploration

   
Bufotes viridisHyla arborea 
Pseudopus apodusHierophis gemo-
nensis   Malpolon insignitus 
   Natrix natrix  
Telescopus fallax   Zamenis situ-
la   Hemidactylus turcicus 
  Podarcis melisellensis    
       
-
       
Podarcis siculus
Testudo her-
manniCaretta caretta
    
  Elaphe quatuorlineata   
 
    Xerotyphlops vermicularis 
       


         -


-

Materials and methods

-
    -
     

    
       
        


1. 
2. 
3. 
 
 
 
 
 
9. 
 
11. 
12. 
13. 
 
 
 
 
 
19. 
 
21. 
22. 
Herpetozoa 33: 191–205 (2020)
herpetozoa.pensoft.net
193
Figure 1. A.
B. C. 

herpetozoa.pensoft.net
Bruno Schmidt et al.: Herpetofauna of Dugi Otok island, Croatia194
23. 
 
 
 
 
 
29. 
 



    
-

Results and discussion
-

      

    Pelophylax ridibundus and
Table 1.

Systematic species list Localities
detected in this
survey
Literature records Red Book
status
***
Conservation
status
Amphibians
*Bufo bufo  LC
1. Bufotes viridis







LC 

2. Hyla arborea






LC 

*Pelophylax ridibundus

 LC
Reptiles
3. Testudo hermanni

  NT 

 Trachemys scripta

  /
 Caretta caretta

1

 

 Hemidactylus turcicus

 


LC
 Podarcis melisellensis









LC 

 Podarcis siculus

 

LC
9. Pseudopus apodus







LC 

*Xerotyphlops vermicularis

 NA
 Elaphe quatuorlineata



 NT 

11. Hierophis gemonensis






LC 

12. Malpolon insignitus








LC
13. Natrix natrix

 

LC
 Telescopus fallax



NT 

 Zamenis situla

 


NT 

*Vipera ammodytes

 LC 



Herpetozoa 33: 191–205 (2020)
herpetozoa.pensoft.net
195
Bufo bufo   Telescopus fal-
lax, Xerotyphlops vermicularis and Vipera ammodytes
     P. ridibundus, B. bufo,
X. vermicularis and V. ammodytes


       
-
     C. caretta  
  T. hermanii, E. quatorlineata, T. fallax and
Z. situla  



      
 
       -
        

 
         
-

Amphibia
Bufo bufo (Linnaeus, 1758) – Common Toad
    B. bufo 
   
        

-
-


B. bufo





Bufotes viridis (Laurenti, 1768) – European Green Toad
B. viridis







       -



Hyla arborea (Linnaeus, 1758) – European Tree Frog
  H. arborea  


Table 2.-

Dugi Otok Kornati Žut Murter Pag Pašman Prvić Ugljan Vir Žirje Iž Olib
Surface area (km2): 113 32 15 18 284 60 2.4 51 22 15 17 26
Amphibians
Bufo bufo  *
Bufotes viridis  
Hyla arborea  
Pelophylax ridibundus *
Reptiles
Testudo hermanni  
Emys orbicularis   
Trachemys scripta  
Caretta caretta  
Hemidactylus turcicus  
Tarentola mauritanica 
Lacerta trilineata
Podarcis melisellensis    
Podarcis siculus      
Pseudopus apodus  
Xerotyphlops vermicularis *
Dolichopis caspius 
Elaphe quatuorlineata  
Hierophis gemonensis  
Malpolon insignitus  
Natrix natrix  
Platyceps najadum
Telescopus fallax    
Zamenis longissimus
Zamenis situla    
Vipera ammodytes * 
Total number 19 7 7 2 19 2 3 9 2 10 3 2
herpetozoa.pensoft.net
Bruno Schmidt et al.: Herpetofauna of Dugi Otok island, Croatia196

     

     
    
  

   -
HylaH. arborea.
       -

  
    


    
H. ar-
borea
        
        

Pelophylax ridibundus (Pallas, 1771) – Marsh Frog
Pelophylax ridibundus
Rana ridibunda-

       



B. viridis

-

 

Reptilia
Testudo hermanni Gmelin, 1789 – Hermann’s Tortoise
 
   -
  




        
 
  -
       
Figure 2.

Herpetozoa 33: 191–205 (2020)
herpetozoa.pensoft.net
197
Figure 3. A. (Testudo hermanni
B. A Elaphe quatuorlineata
  C. Zamenis situla  

herpetozoa.pensoft.net
Bruno Schmidt et al.: Herpetofauna of Dugi Otok island, Croatia198
        
        -

-
    
       
 
    



Trachemys scripta (Thunberg in Schoep, 1792)
Pond Slider
-

 
  

      
   
-
-


  

         
       




Caretta caretta (Linnaeus, 1758) – Loggerhead Sea Turtle
       

       





     
-

-
-


Hemidactylus turcicus (Linnaeus, 1758) – Turkish Gecko
     
       
      

      

   
    
  -


-
       

Podarcis melisellensis (Braun, 1877) – Dalmatian Wall
Lizard


   modesta -

      
       
   -

-




Podarcis siculus (Ranesque-Schmaltz, 1810) – Italian
Wall Lizard


-
-
    
  P. melisellensis
       
        
          -
-
   




 



Pseudopus apodus (Pallas, 1775) – European Glass
Lizard
Pseudopus apodus


Herpetozoa 33: 191–205 (2020)
herpetozoa.pensoft.net
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  
      
         
        

        


Xerotyphlops vermicularis (Merrem, 1820) – European
Worm Snake
    

-
      
        
-
    

    
  -





Elaphe quatuorlineata (Lacepede, 1789) – Four-Lined
Snake
   E. quatuorlineata  
-

-
     
-

       


-




Hierophis gemonensis (Laurenti, 1768) – Balkan Whip
Snake
    H. gemonensis    

 
     
       
      







Malpolon insignitus (Georoy de St-Hilaire, 1809) –
Eastern Montpellier Snake
M. insignitus    -
       
    

       
      

-

    
   -



Natrix natrix (Linnaeus, 1758) – Grass Snake



 

     



       

        





Telescopus fallax (Fleischmann, 1831) – European Cat
Snake

-

-

  
  




herpetozoa.pensoft.net
Bruno Schmidt et al.: Herpetofauna of Dugi Otok island, Croatia200
     


-


 
T.
fallax
         


-

Zamenis situla (Linnaeus, 1758) – Leopard Snake
       
-

       

  
        -




Vipera ammodytes (Linnaeus, 1758) Nose-Horned Viper
   
-
 
        
      -


E. quat-
uorlineata  Z. situla or T. fallax 
-




Species distribution and conservation


  
       



-

-
    


-
B. viridis




-
-

      
       
-
    
     
  
      
        

       
      
      

 


        
      
P. melisellensis, H. turcicus,
H. gemonensis and M. insignitus -

T. herman-
ni    


Threats to native species
      -
          
     

      
     
     

        


      
     
      

-
Herpetozoa 33: 191–205 (2020)
herpetozoa.pensoft.net
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   -
        
   

-
-



-
    
Gambusia holbrooki-
        

  -

  -
    -
    
T. scripta

   -

-
  -
-
     

        -

      



-



-


         -
Felis catus   


 
    
        
     -



  
       
cats, P. siculus


   


-


    
         
Herpestes auropunctatus    
    
-
    

V. ammodytes
         




   
     

-


    

Conclusion
    -
         
  

 B. bufo, P. ridibundus, X. vermicularis and
V. ammodytes-
  
  

-

H. arborea and B. viridis.

N. natrix-


-
Z. situla or E. quatuorlineata 


      
cats F. catusG. holbrooki
T. scripta


-
Z. situla, C. caretta, T. hermanni and E. quatuorlin-
eata       -
herpetozoa.pensoft.net
Bruno Schmidt et al.: Herpetofauna of Dugi Otok island, Croatia202



      

Acknowledgements
      


      

-

     

      -
  
   

References
        
        


-
-

 
-

   

     

        


 

     
        


-


    
    



      
 -

-
-


 


-

-
-





          




  


 



   -


     

   Eu-
rotestudo hermanii, Emys orbicularis, Bombina bombina and Bombina
variegata-
      Eurotestudo hermanii,
Emys orbicularis, Bombina bombina i Bombina variegata 

Typhlops vermicularis-
-

     

 -
-
   








  

Herpetozoa 33: 191–205 (2020)
herpetozoa.pensoft.net
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-
-
       -

           
-




      
  
-

   
     -

-
Dolichophis caspius


       
        -
     
 
     -

  
  
 -
-
-




       

-


   
       

          
   


  -
        




        
-
 -


Felis catus

-

          
Caretta caretta-
-
 

       
  Trachemys scripta elegans   -


 

      

         
       -
-
-

            
        
       
         


-

        
     


Testudo


       
         
       



      Elaphe quatuorlineata (,

-


    -
        
 


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
-

herpetozoa.pensoft.net
Bruno Schmidt et al.: Herpetofauna of Dugi Otok island, Croatia204
   nd
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
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      
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 
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   
  
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         
       

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-
    -
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
        

 
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         
      
-
-
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   -
Podarcis sicula
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 -

 -
        Caret-
ta caretta       
     


         -
       


    -

Podarcis sicula and
P. melisellensis


Platyceps najadum dahlia 
  -

         




      
     

     -

-
-
     

         
     


   
         
       

Typhlops 
          
Typhlops-

           -
          
     -
      



          
-

  -
   
  Vipera ammodytes   



  -




Gambusia holbrooki  -
        
       

Herpetozoa 33: 191–205 (2020)
herpetozoa.pensoft.net
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       
-
       

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
-
  

        

Natrix natrix (Lin-
Zamenis longissimus
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

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Supplementary material 1
List of visited localities
      
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
         
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       
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
... To date, the northernmost confirmed native population is in the area of Podgorica, Montenegro (Gvozdenović 2020) which extended the northern limit of the species from northern Lake Skadar in Montenegro (Crnobrnja-Isailović and Džukić 1995;Aghasyan et al. 2017). The species was also reported from Dugi Otok, an island in Croatia (Grillitsh et al. 1999), although this record was considered unreliable and to date the species is considered as not occurring in Croatia (Schmidt et al. 2020). ...
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The Xerotyphlops vermicularis (Merrem, 1820) complex represents small, burrowing snakes that occur from the Balkan Peninsula to Afghanistan and generally they are mostly observed during the springtime. In the present study, we report new records of this snake (10 individuals observed) from Elenite village in coastal Bulgaria. According to current knowledge, they represent the northernmost locality of the species in the Balkan Peninsula. We expand the known distribution of X. vermicularis and help to fill information gaps.
... Although, Grillitsch et al. (1999) published a record of X. vermicularis on Dugi Otok island in Croatia, Jelić et al. (2015) consider this record as highly questionable. Additionally, recent field research failed to confirm presence of this species in the Croatia (Štih et al. 2013(Štih et al. , Schmidt et al. 2020, what indicate that the occurrence of this species is very unlikely in Croatia. Also, according IUCN (2020) presence of the species is uncertain for Bosnia and Herzegovina. ...
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Diversity of reptile fauna, as well as threat factors were investigated during April and May 2019 in the settlement Mareza. Field methodology included active searching and visual observation of species along defined transects. In total, 20 reptile species were recorded, what comprises about 55 % of reptile fauna known for Montenegro. According to obtained results, area of Mareza can be considered as important reptile diversity hotspot in Montenegro. First finding of Xerotyphlops vermicularis in this area contribute to knowledge of its distribution range. Three identified species (Emys orbicularis, Testudo hermanni and Elaphe quatuorlineata) are listed on Annex II of the Habitat Directive. None of identified species are vulnerable, endangered or critically endangered, upon the IUCN Red List. Almost all identified species are protected on national level. Main threat factors for reptile fauna in the area of Mareza are: urbanization, habitat fragmentation and destruction, fires, illegal landfills, direct killing by locals and road killing.
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The last species list of the European herpetofauna was published by Speybroeck, Beukema and Crochet (2010). In the meantime, ongoing research led to numerous taxonomic changes, including the discovery of new species-level lineages as well as reclassifications at genus level, requiring significant changes to this list. As of 2019, a new Taxonomic Committee was established as an official entity within the European Herpetological Society, Societas Europaea Herpetologica (SEH). Twelve members from nine European countries reviewed, discussed and voted on recent taxonomic research on a case-by-case basis. Accepted changes led to critical compilation of a new species list, which is hereby presented and discussed. According to our list, 301 species (95 amphibians, 15 chelonians, including six species of sea turtles, and 191 squamates) occur within our expanded geographical definition of Europe. The list includes 14 non-native species (three amphibians, one chelonian, and ten squamates).
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Loggerhead turtles Caretta caretta spend most of their life in large marine areas occupying a variety of habitats where they are exposed to different types of threats. Among these, marine litter is known to pose a risk of entanglement or ingestion. Areas of risk exposure can be identified where the species overlap with litter accumulations, but gathering data on this highly mobile species and marine litter, especially in high sea areas, is challenging. Here we analysed 5 years of sea turtle and marine litter data collected by a network of research bodies along fixed trans-border transects in the Mediterranean Sea. Ferries were used as observation platforms to gather systematic data on a seasonal basis using standard protocols. The Sightings Per Unit of Effort was used as an index to compare loggerhead turtle sightings over time and space, and risk exposure areas were assessed based on seasonal overlap of species hot spots and high-density plastic areas revealed by kernel analysis. In almost 180000 km surveyed, 1258 sea turtles were recorded, concentrated mostly during all seasons in the central Adriatic Sea and Sardinia-Sicilian channels, and during spring in central Tyrrhenian. Plastic was the highest fraction of litter items detected. Several areas of higher risk exposure, both permanent and seasonal, were identified, mainly in the Adriatic Sea and during the spring-summer seasons. Records of both species and floating litter were highly variable, underlying the need for continuous long-term monitoring to develop sound conservation and management measures, especially in the identified areas of risk exposure. https://www.int-res.com/abstracts/esr/v40/p107-121/