Population and ecological characteristics of the dice snake, Natrix tessellata (Laurenti, 1768), in lower portions of the Vrbanja River (Republic of Srpska, Bosnia and Herzegovina)

Despite their comparative richness and accessibility in the Republic of Srpska and in Bosnia and Herzegovina in general, population studies of reptiles have not been performed in Srpska until recently. For example, one of the most common snake species in this area is the dice snake; nevertheless, previous studies have only reported its distribution. The aim of the present study was to analyze characteristics of the dice snake population along the Vrbanja River. Animals were processed during 2011 throughout their activity period. In total, 199 individuals of all ages were collected. We observed substantial differences in numbers of animals captured in different habitat types classified according to the level of anthropogenic influence. Unexpectedly, the largest number of snakes was captured in the zone with the highest anthropogenic influence, while the smallest number was observed in the zone with no anthropogenic pressures. The above is probably connected with the observed greater number of their most common prey, as well as the absence of raptors in areas with human impact. In the surveyed area, dice snakes feed predominantly on cyprinid fishes, and their reproductive traits are in accord with literature data.