Treefrogs adjust their acoustic signals in response to harmonics structure of intruder calls

Author(s)

Foratto, Roseli Maria ^{[1, 2, 3]} ; Llusia, Diego ^{[4, 5, 6]} ; Toledo, Luis Felipe ^{[1, 2, 3]} ; Forti, Lucas Rodriguez ^{[2, 3, 7]}

Affiliation

^[1] Univ Estadual Campinas, Inst Biol, Programa Posgrad Biol Anim, Caixa Postal 6109, R Monteiro Lobato 255, BR-13083970 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Inst Biol, Dept Biol Anim, Lab Multiusuario Bioacust LMBio, Caixa Postal 6109, R Monteiro Lobato 255, BR-13083970 Campinas, SP - Brazil

^[3] Univ Estadual Campinas, Inst Biol, Dept Biol Anim, Lab Hist Nat Anfibios Brasileiros LaHNAB, Caixa Postal 6109, R Monteiro Lobato 255, BR-13083970 Campinas, SP - Brazil

^[4] Univ Autonoma Madrid UAM, Fac Ciencias, Dept Ecol, Terr Ecol Grp TEG, Ciudad Univ Cantoblanco, Calle Darwin 2, Madrid 28049 - Spain

^[5] Univ Autonoma Madrid, Ctr Invest Biodiversidad & Cambio Global CIBC UAM, Calle Darwin 2, Madrid 28049 - Spain

^[6] Univ Fed Goias UFG, Inst Ciencias Biol, Dept Ecol, Lab Herpetol & Comportamento Anim, Campus Samambaia, Ave Esperanca S-N, BR-74001970 Goiania, Go - Brazil

^[7] Univ Fed Bahia, Inst Biol, Campus Ondina, R Barao de Jeremoabo 668, BR-40170115 Salvador, BA - Brazil

• Document type: Journal article
• Source: BEHAVIORAL ECOLOGY; v. 32, n. 3, p. 416-427, MAY-JUN 2021.
• Web of Science Citations: 0

Abstract

Spectral properties of animal acoustic signals may help individuals to assess the characteristics of rivals and to adjust their competitive strategies in territorial disputes. Thus, we hypothesized that the distribution of energy across frequency bands in anuran calls determines behavioral responses in male-male competition. Using playback experiments, we investigated the relevance of the harmonic calls in the acoustic communication of the treefrog Dendropsophus minutus. We exposed territorial males to three synthetic acoustic stimuli composed of aggressive notes: 1) standard call (all harmonics and peak frequency corresponding to the second band); 2) inverted-energy call (all harmonics and peak frequency corresponding to the first band); and 3) concentrated-energy call (all energy contained in the second harmonic). Males responded aggressively to all stimuli, mainly by increasing the rate and duration of their aggressive notes. However, when exposed to stimuli with different harmonic configurations, males changed the harmonic structure of their own calls, emitting more A- and B-notes with peak power in the fundamental frequency, particularly when exposed to the concentrated-energy call. Our results suggest that male frogs may use the harmonic structure of calls to assess opponents and modulate territorial and aggressive behavior, triggering complex acoustic adjustments. This study contributes to our knowledge about the functions of acoustic traits in amphibian social interactions, and particularly of the presence of harmonics that has received less attention compared to other acoustic properties in the study of animal acoustic communication. (AU)

• FAPESP's process: 16/25358-3 - The chytrid fungus: from its origins to its consequences
• Grantee: Luis Felipe de Toledo Ramos Pereira
• Support Opportunities: Research Projects - Thematic 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
• 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