Preliminary overview of body condition variation among dice snake populations from transboundary Lake Prespa

Abstract

Studies of body condition in snakes are generally lacking and were only done on a few species and with limited sample sizes. Additionally, almost no studies considered how different factors affect body condition. We used a large dataset amassed over a 15 year-long ecological study to make a preliminary screening of body condition index (BCI) variation in a metapopulation of dice snakes (Natrix tessellata) in the region of Lake Prespa. We considered how factors such as sex, food, colour morph, locality and time affect BCI. We demonstrate a positive effect of food (relatively less in males), and lower BCI in females. Importantly, there is a strong seasonal effect, summer months having a positive effect as opposed to spring. The results of our study raise important considerations for future studies on snake BCI, but also conservation of freshwater ecosystems.