Fig. 4

Number of male frogs that choose meows, short calls, or staccato calls as their first calls and last calls under different NLP component stimuli. Chi-square test: First_Fj, \({\upchi }_{2}^{2}\) = 13.37, P = 0.001; Last_Fj χ² = 62.84, P < 0.001; First_Sh, \({\upchi }_{2}^{2}\) = 114.1, P = 0.001; Last_Sh \({\upchi }_{2}^{2}\) = 13.3, P = 0.001