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Vol. 53, 2014
A global overview on the diet of the dice snake (Natrix tessellata) from a geographical
perspective: foraging in atypical habitats and feeding spectrum
widening helps colonisation and survival under suboptimal conditions
for a piscivorous snake
András
Weiperth1, Tibor Gaebele2, Imre Potyó1
and Miklós Puky1*
1MTA
Centre for Ecological Research, Danube Research Institute, Karolina út
29, Budapest 1113, Hungary
2Szent István University, Faculty of Veterinary
Science, István u. 2, Budapest 1078, Hungary
Abstract
Background: The dice snake (Natrix tessellata Laurenti, 1768) is
generally considered to be a fully or partially piscivorous freshwater
snake species. The aim of the study was to make the first global
overview on the taxonomy and geographical distribution of the species
based on own observations, available databases and the special
literature.
Results: Besides freshwaters, N. tessellata turned out to hunt
also in marine and terrestrial habitats predating on at least 29 and 15
species, respectively. On the basis of our data and the literature
altogether, 113 prey taxa, mostly fish, were listed but 20% of them
were invertebrates, amphibians, reptiles and mammals. The importance of
non-fish species in the diet was especially pronounced in deserts, high
mountains and in dry Mediterranean areas. In spite of the wide feeding
spectrum, only fish and amphibians were found to be predominant food
items over the whole species' range. Fish dominated the catch of the
dice snake in most quantitative studies, except one survey in Turkey,
where the ratio of non-fish prey items was over 50%.
Conclusions: The global analysis of
the diet of the dice snake revealed a feeding spectrum
characteristically changing over the broad distribution area including
non-fish prey as well as taxa from marine and terrestrial habitats. The
analysis of the feeding spectrum separated four large geographical
units with further distinctions in Central and Eastern Europe. Such
diversity helps explain why this species was able to colonise a large
and diverse Eurasian range.
Key words: Natrix
tessellata; Reptilia;
Diet; Feeding spectrum.
*Correspondence: E-mail: puky.miklos@okologia.mta.hu
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