Effects of the urban environment on the developmental stability, size and body condition of dice snakes (Natrix tessellata) living in artificial lakeside habitats

Urban oasis? Abundant dice snake (Natrix tessellata) populations along artificial lakeside habitats in urban landscapes

“…Altogether, the presence of suitable microhabitats with reduced predation pressure and the availability of abundant, stable food resources in urban areas may create favourable habitats for dice snakes. Additionally, as a supporting observation, our previous study revealed that dice snakes residing in more urbanized areas exhibit larger body sizes (Mészáros et al 2023), suggesting that urban habitats may offer new ecological opportunities for dice snakes. Contrary to previous studies on the effects of roads on wildlife (Fahrig and Rytwinski 2009;Farias et al 2022;Rytwinski and Fahrig 2012;Wagner et al 2021), dice snake abundance was positively correlated with road cover and road proximity (Fig.…”

“…We examined the abundance of dice snakes (Natrix tessellata) residing in the artificial lakeside habitats of Lake Balaton, exploring correlations with various aspects of urbanization assessed at both landscapeand local-scales. In our previous study we found that urban land use cover, road cover and the proximity of main roads had a negative effect on developmental stability, while urban land use cover and the area of the artificial rock and concrete shoreline protection structures had a positive effect on the body size of the dice snakes (Mészáros et al 2023).…”

“…Additional to the negative effect of urban land cover and human disturbance, we also predicted that; (iv) road density; and (v) the proximity of roads would both negatively influence snake abundance due to road pollutants (Dixon et al 2022;Yang et al 2014) and higher risk of road mortality (Hallisey et al 2022). Moreover, it has been shown previously that the area of road cover and the proximity of roads positively correlate with the fluctuating asymmetry of dice snakes assuming higher developmental instability (Mészáros et al 2023). This, in turn, could indirectly impact the survival of individuals, potentially contributing to a decline in snake populations.…”

“…Given that previous findings indicated a negative correlation between urbanization and reptile abundance (Doherty et al 2020) and developmental stability (Mészáros et al 2023), attributed to the higher pollution rates (Tombesi et al 2014), our first prediction was that at the landscape scale (i) urban land use cover would negatively, while; (ii) natural or semi-natural land cover would positively affect the abundance of dice snakes. We also predicted that; (iii) populations residing in larger settlements might experience heightened human disturbance due to a larger number of inhabitants and tourists resulting in decreased snake abundance.…”

“…At the local-scale, our predictions were that, despite the adverse impacts of urbanization, (vi) the artificial rock and concrete shoreline protection structures would play a crucial role in determining the abundance of dice snakes (Conelli et al 2011). We found in our previous study that the human-made rock-covered shoreline had a positive effect on snake body size (Mészáros et al 2023) by presumably supporting abundant and stable food resources (Eötvös et al 2018). Additionally, (vii) a greater cover of emergent vegetation was predicted to provide suitable habitat for sheltering, nesting and hibernation.…”