Differential and additive effects of natural biotic and anthropogenic noise on call properties of Odontophrynus americanus (Anura, Odontophryinidae): Implications for the conservation of anurans inhabiting noisy environments

GRENAT, PABLO R.; POLLO, FAVIO E.; FERRERO, MARÍA DE LOS ÁNGELES; MARTINO, ADOLFO L.

ECOLOGICAL INDICATORS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2019 vol. 99 p. 67 - 73

1470-160X

Successful reproduction in most anurans isassociated to acoustic communication and negative effects of auditory maskingby natural biotic and anthropogenic noise are known in this group. However, thepotential additive effect of both noise types has been scarcely studied. We examinein situ the acoustic variation of 135males (n=975calls) of Odontophrynusamericanus in areas from Central Argentina with (TN) and without traffic noise (N-TN) andin presence (Ch) or absence (N-Ch) of chorus. The effect of noise condition onfour call properties (call duration [CD], intercall interval [ICI], pulse rate[PR] and dominant frequency [DF]) were analyzed using linear mixed models (LMMand GLMM). A Principal Component Analysis (PCA) was performedto identify the acoustical properties that best accounted for variation among allpossible noise conditions (N-TN/N-Ch; N-TN/Ch; TN/N-Ch and TN/Ch). PR andDF showed significant higher values in TN than N-TN sites while a significantincrease in ICI and a decrease in DF were found in chorus situation. Analyzingcombined effects, PR significantly increased in N-TN/N-Ch conditionand decreased under TN/Ch. ICI was significantly higher in N-TN/N-Ch condition. PCA showed aseparation of males calling in noisy condition mainly associated to higher valuesof DF and CD. The acoustic variation observed in noisy environments could haveimplications in the reproductive strategies of the individuals although newstudies should be conducted to analyze the effect of this variation on therecognition and choice by females. Our outcomes highlight the importance ofconducting in situ behavioral studiesconsidering the additive effects of different environmental noise sources.