摘要
Male large odorous frogs(Odorrana graminea)have been shown to have a rich vocal repertoire and their calls contain harmonics that extend into the ultrasonic range,much like calls of male O.tormota,a sympatric species.Whereas vocalizations of male O.tormota exhibit nonlinear characteristics and contain individual signatures,it is unclear whether or not those of O.graminea do.We carried out an extensive study of the vocalizations of male O.graminea with the goal of investigating whether they:(1)contained nonlinear phenomena(NLP),(2)carried individual signatures.We recorded and analyzed 1770 vocal calls from nine males.Their calls were classifiable into two distinct categories(one-note calls and multi-note calls).Of these,one-note complex/steep-frequency modulation call was the most abundant call-type.These calls showed diverse frequency modulation patterns,and abundant presence of NLP.Various basic spectral and temporal pa ra meters of such calls were individually distinct.Kruskal-Wallis Analysis of Rank test showed that the calls from individual males differed significantly.Subsequent discriminant function analysis(DFA)showed that 54.7%of the calls could be correctly assigned to individual.These results suggested that male O.graminea might be able to discriminate neighboring frogs from strangers acoustically.However,further research is necessary to demonstrate this capacity behaviorally.
基金
by a grant from the National Natural Science Foundation of China to F.Zhang(NSFC grants 31640073,31872230)。
