Savannah roars: The vocal anatomy and the impressive rutting calls of male impala (Aepyceros melampus) – highlighting the acoustic correlates of a mobile larynx
| Autor: | Vera Menges, Elena V. Volodina, Roland Frey, Guido Fritsch, Kseniya O. Efremova, Christina Gerlach, Ilya A. Volodin, Ruben Portas, Jörg Melzheimer, Katja von Dörnberg |
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| Rok vydání: | 2019 |
| Předmět: |
Male
0301 basic medicine Larynx Felidae Histology vocal fold roaring mammal ruminant Vocal Cords formants 03 medical and health sciences 0302 clinical medicine vocal tract biology.animal vocal posture otorhinolaryngologic diseases medicine sexual selection Animals fundamental frequency larynx retraction polygyny Bovidae Molecular Biology Ecology Evolution Behavior and Systematics biology Arytenoid cartilage Original Articles Acoustics Cell Biology Anatomy 030104 developmental biology medicine.anatomical_structure Formant Harem Antelopes Vocal folds Aepyceros melampus Original Article Laryngeal Muscles Vocalization Animal 030217 neurology & neurosurgery Vocal tract Hyoid apparatus Developmental Biology |
| Zdroj: | Journal of Anatomy Journal of anatomy, 236(3):398-424 |
| ISSN: | 1469-7580 0021-8782 |
| DOI: | 10.1111/joa.13114 |
| Popis: | A retractable larynx and adaptations of the vocal folds in the males of several polygynous ruminants serve for the production of rutting calls that acoustically announce larger than actual body size to both rival males and potential female mates. Here, such features of the vocal tract and of the sound source are documented in another species. We investigated the vocal anatomy and laryngeal mobility including its acoustical effects during the rutting vocal display of free‐ranging male impala (Aepyceros melampus melampus) in Namibia. Male impala produced bouts of rutting calls (consisting of oral roars and interspersed explosive nasal snorts) in a low‐stretch posture while guarding a rutting territory or harem. For the duration of the roars, male impala retracted the larynx from its high resting position to a low mid‐neck position involving an extensible pharynx and a resilient connection between the hyoid apparatus and the larynx. Maximal larynx retraction was 108 mm based on estimates in video single frames. This was in good concordance with 91‐mm vocal tract elongation calculated on the basis of differences in formant dispersion between roar portions produced with the larynx still ascended and those produced with maximally retracted larynx. Judged by their morphological traits, the larynx‐retracting muscles of male impala are homologous to those of other larynx‐retracting ruminants. In contrast, the large and massive vocal keels are evolutionary novelties arising by fusion and linear arrangement of the arytenoid cartilage and the canonical vocal fold. These bulky and histologically complex vocal keels produced a low fundamental frequency of 50 Hz. Impala is another ruminant species in which the males are capable of larynx retraction. In addition, male impala vocal folds are spectacularly specialized compared with domestic bovids, allowing the production of impressive, low‐frequency roaring vocalizations as a significant part of their rutting behaviour. Our study expands knowledge on the evolutionary variation of vocal fold morphology in mammals, suggesting that the structure of the mammalian sound source is not always human‐like and should be considered in acoustic analysis and modelling. Male impala retract the larynx while producing their impressive rutting roars. The low fundamental frequency of these roars is produced by a highly modified vocal fold, a ‘vocal keel’. The anatomical and acoustical correlates of male impala's mobile larynx are discussed. |
| Databáze: | OpenAIRE |
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