Behavioural response evoked by conspecific distress calls in two neotropical treefrogs

Author(s)

Forti, Lucas Rodriguez ^{[1, 2]} ; Bella Sanches Forti, Anna Barbara ^[3] ; Marquez, Rafael ^[4] ; Toledo, Luis Felipe ^{[1, 2]}

Affiliation

^[1] Univ Estadual Campinas, Inst Biol, Dept Biol Anim, Lab Hist Nat Anfibios Brasileiros LaHNAB, Sao Paulo - Brazil

^[2] Univ Estadual Campinas, Inst Biol, Dept Biol Anim, Lab Multiusuario Bioacust LMBio, Sao Paulo - Brazil

^[3] Fac Direito Sorocaba, Rua Doutora Ursulina Lopes Torres, Sao Paulo - Brazil

^[4] Museo Nacl Ciencias Nat CSIC, Dept Biodiversidad & Biol Evolut, Fonoteca Zool, Madrid - Spain

• Document type: Journal article
• Source: Ethology; v. 123, n. 12, p. 942-948, DEC 2017.
• Web of Science Citations: 4

Abstract

Anurans emit distress calls when attacked by predators as a defensive mechanism. As distress calls may trigger antipredator behaviour even in individuals that are not under attack, we tested whether this defensive behaviour induced behavioural changes in neighbouring conspecifics. We compared the behavioural responses of two species of Neotropical hylid frogs (genus Boana) to conspecific distress calls and white noise. Individuals of both species interrupted their vocal activity and decreased call rate after hearing the distress call. Natural variation on signal intensity calibrated among the nearest neighbours did not influence the response and we did not observe negative phonotaxis after any acoustic stimulus. Despite the fact that many predators are acoustically oriented, we could not determine if such response (reduced call rate) was induced by risk assessment or by the masking effect on advertisement calls. Boana faber responded similarly to white noise and distress calls, while B. bischoffi responded more intensely to distress calls. Duration of silence after playbacks in B. faber was longer than B. bischoffi. We suggest that, if the signals are interpreted as a risk cue by neighbouring conspecifics, each species may be preyed upon by different predators, as they may have led to distinct defensive strategies and different responses to distress calls. If risk assessment information is included in distress calls, it triggers behavioural responses only in the nearest neighbours, as we did not observe responses on the vocal activity of the interspecific chorus. Our results add relevant data about acoustic communication and interpretations by anurans, highlighting the importance of considering cues within common and widespread signals. (AU)

• FAPESP's process: 14/23388-7 - Comunication and sensory systems of the anurans of the Atlantic Forest
• Grantee: Luis Felipe de Toledo Ramos Pereira
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/21519-4 - Distress call in frogs: a vocalization with coespecific information?
• Grantee: Lucas Rodriguez Forti
• Support Opportunities: Scholarships in Brazil - Post-Doctoral