Acoustic signals in birds are often influenced by body and beak size(the morphological constraint hypothesis)and may also reflect the sender's condition(the condition dependence hypothesis).However,these ideas hav...Acoustic signals in birds are often influenced by body and beak size(the morphological constraint hypothesis)and may also reflect the sender's condition(the condition dependence hypothesis).However,these ideas have seldom been tested in duetting species,where the acoustics of the combined signal could relate to the morphology of both vocalizing individuals.In this study,we investigated whether specific morphological traits—scaled mass index,wing length,and bill surface area—could predict individual and pair-level characteristics of Rufous Hornero(Furnarius rufus) duets.In this species,partners partially overlap their songs,with males producing faster-paced,lower-pitched songs compared to females.Morphology was most closely associated with the timing of syllables within duets,though different traits were linked to timing in each sex.Females in better condition(indicated by a higher scaled mass index) and with longer wings produced duet phrases with greater variation in syllable duration.In contrast,males with larger bills showed greater variation in both syllable duration and gaps between syllables.The degree of temporal overlap in syllables increased with female condition,but not male condition,suggesting that overlap may signal female quality.Additionally,minimum duet frequency was negatively associated with male condition,indicating that lower-frequency duets may serve as an honest signal of male quality.These findings indicate that the timing of syllables and minimum duet frequency are both condition-dependent and constrained by morphology,allowing receivers to gain multiple insights into the morphology of duetting partners in Rufous Horneros.展开更多
基金Ph.D.scholarships by the Brazilian Federal Agency for Support and Evaluation of Graduate Education(CAPES)(Finance Code 001)a CAPES postdoctoral fellowship (grant 88887.469218/2019-00)+4 种基金in part,by the So Paulo Research Foundation (FAPESP),Brazil.Process Number#2024/13237-3funding was provided by the Animal Behavior Society (ABS Student Research Grant to P.S.A.)the Association of Field Ornithologists (E.Alexander Bergstrom Memorial Research Award to P.S.A.)the American Ornithological Society(Postdoctoral Research Award to P.D.)logistical and financial support from the Universidade de Brasília's Graduate Program in Ecology,in collaboration with the Programa de Excelência Academica (PROEX/CAPES 1789/2015)。
文摘Acoustic signals in birds are often influenced by body and beak size(the morphological constraint hypothesis)and may also reflect the sender's condition(the condition dependence hypothesis).However,these ideas have seldom been tested in duetting species,where the acoustics of the combined signal could relate to the morphology of both vocalizing individuals.In this study,we investigated whether specific morphological traits—scaled mass index,wing length,and bill surface area—could predict individual and pair-level characteristics of Rufous Hornero(Furnarius rufus) duets.In this species,partners partially overlap their songs,with males producing faster-paced,lower-pitched songs compared to females.Morphology was most closely associated with the timing of syllables within duets,though different traits were linked to timing in each sex.Females in better condition(indicated by a higher scaled mass index) and with longer wings produced duet phrases with greater variation in syllable duration.In contrast,males with larger bills showed greater variation in both syllable duration and gaps between syllables.The degree of temporal overlap in syllables increased with female condition,but not male condition,suggesting that overlap may signal female quality.Additionally,minimum duet frequency was negatively associated with male condition,indicating that lower-frequency duets may serve as an honest signal of male quality.These findings indicate that the timing of syllables and minimum duet frequency are both condition-dependent and constrained by morphology,allowing receivers to gain multiple insights into the morphology of duetting partners in Rufous Horneros.
