Impacts of temperature, water level and density on cannibalism of larval Bufotes variabilis (Pallas, 1769)

Cannibalism is a behavioural characteristic that is defined in a wide range of animals and is widely seen in aquatic ecosystems and in more than 90% of the life cycle of animals, especially amphibians. Climate change is one of the most important threats to diversification. The studies show that the temperature changes the interaction of species and affects the cannibalism rate. In this study, to investigate the effect of emerging climate change on cannibalism, the independent and interactive effects of three factors including (high and low temperature), density (high and low density), and fluctuations in water levels (high, low and decreasing water levels) on head, tail and whole body cannibalism were investigated in the larval of Green toad (Bufotes variabilis) for the period of 10 months. In this study, generally, the highest rate of cannibalism was observed in low density (59.44%), high temperature (53.33%) and low water level (45%). In the interactive study, the highest percentage of cannibalism observed in the treatment of high temperature/low water level/low density with 90%. In contrast, the lowest percentages of cannibalism were recorded in low temperature/low water levels/low density with 20%. The results of ANOVA analysis indicated that temperature and density have a significant effect on the level of cannibalism. In contrast, this effect was not significant for fluctuations in the water level. The interaction of all three factors of temperature, density and water level also had a significant effect on cannibalism.