Contextual behavioural plasticity in Italian agile frog (Rana latastei) tadpoles exposed to native and alien predator cues [RESEARCH ARTICLE]

Andrea Gazzola, Alessandro Balestrieri, Giovanni Scribano, Andrea Fontana, and Daniele Pellitteri-Rosa Predation is a strong driver for the evolution of prey behaviour. To properly assess the actual risk of predation, anuran tadpoles mostly rely on water-borne chemical cues, and their ability to evaluate environmental information is even more crucial when potential predators consist of unknown alien species. Behavioural plasticity, that is the capacity to express changes in behaviour in response to different environmental stimuli, is crucial to cope with predation risk. We explored the defensive behaviour of Italian agile frog (Rana latastei) tadpoles when exposed to the chemical cues of two predators’ species, one native (dragonfly larvae) and one alien (red swamp crayfish). Firstly, we observed if a sensible life history trait (i.e. hatching time) might be affected by native predatory cues. Secondly, we recorded a suite of behavioural responses (activity level, lateralization and sinuosity) to each cue. For assessing lateralization and sinuosity, we developed a C++ code for the automatic analysis of digitally recorded tadpole tracks. Hatching time seemed not to be affected by the potential risk of predation, while both predator species and diet affected tadpoles’ defensive behaviour. Tadpoles responded to predator threat by two main defensive strategies: freezing and "zig-zagging". While the first behaviour had been previously reported, the analysis of individua...
Source: Journal of Experimental Biology - Category: Biology Authors: Tags: RESEARCH ARTICLE Source Type: research