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)

Abstract

Despite their comparative richness and accessibility in the Republic of Srpska and in entire Bosnia and Herzegovina, population studies of reptiles have not been performed until recently. For example, one of the most common snake species in this area is the dice snake; nevertheless, previous studies only reported its distribution. The aim of the present study was to analyse 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 influences. 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 predominately on cyprinid fishes, and their reproductive traits are in accord with literature data.