The postnatal ontogeny of the sexually dimorphic vocal apparatus in goitred gazelles (Gazella subgutturosa)

Abstract

This study quantitatively documents the progressive development of sexual dimorphism of the vocal organs along the ontogeny of the goitred gazelle (Gazella subgutturosa). The major, male-specific secondary sexual features, of vocal anatomy in goitred gazelle are an enlarged larynx and a marked laryngeal descent. These features appear to have evolved by sexual selection and may serve as a model for similar events in male humans. Sexual dimorphism of larynx size and larynx position in adult goitred gazelles is more pronounced than in humans, whereas the vocal anatomy of neonate goitred gazelles does not differ between sexes. This study examines the vocal anatomy of 19 (11 male, 8 female) goitred gazelle specimens across three age-classes, that is, neonates, subadults and mature adults. The postnatal ontogenetic development of the vocal organs up to their respective end states takes considerably longer in males than in females. Both sexes share the same features of vocal morphology but differences emerge in the course of ontogeny, ultimately resulting in the pronounced sexual dimorphism of the vocal apparatus in adults. The main differences comprise larynx size, vocal fold length, vocal tract length, and mobility of the larynx. The resilience of the thyrohyoid ligament and the pharynx, including the soft palate, and the length changes during contraction and relaxation of the extrinsic laryngeal muscles play a decisive role in the mobility of the larynx in both sexes but to substantially different degrees in adult females and males. Goitred gazelles are born with an undescended larynx and, therefore, larynx descent has to develop in the course of ontogeny. This might result from a trade-off between natural selection and sexual selection requiring a temporal separation of different laryngeal functions at birth and shortly after from those later in life. J. Morphol. 277:826-844, 2016. © 2016 Wiley Periodicals, Inc.

Individuality of distress and discomfort calls in neonates with bass voices: Wild‐living goitred gazelles (Gazella subgutturosa) and saiga antelopes (Saiga tatarica)

“…The four first formants (F1, F2, F3 and F4) were measured using LPC with Praat DSP package (P. Boersma & D. Weenink, University of Amsterdam, Netherlands, http://www.praat.org). The LPC settings were based on measurements of the oral vocal tract lengths obtained during previous studies: 117 mm for neonate goitred gazelles (Efremova et al., ) and 116 mm for neonate saiga antelopes (Volodin, Sibiryakova, et al., ). The LPC settings for creating the formant tracks were Burg analysis, window length 0.04 s, time step 0.01 s; maximum number of formants 4–5, the maximum formant frequency (the upper limit of frequency range) 5,200‐6,700 Hz (Figure ).…”

“…In most mammals, the nasal vocal tract is longer than the oral vocal tract. This refers not only to saigas with their trunk‐like nose (Volodin, Sibiryakova, et al., ) but also to goitred gazelles with their typical mammalian nose (Efremova et al., ; Volodin et al., ). Correspondingly, the formants of oral calls are always higher than those of nasal calls in goitred gazelles (Efremova, Volodin, Volodina, Frey, Lapshina, et al., ) and saigas (Volodin, Sibiryakova, et al., ).…”

Old and young female voices: effects of body weight, condition and social discomfort on the vocal aging in red deer hinds (Cervus elaphus)

“…This similarity in trends of f0 with male aging expands also to sexual dimorphism of vocal anatomy. The larynx rests lower in the neck in males than in females in both humans (Negus, 1949;Lieberman, 1973;Davidson, 2003) and in four species of ruminants: fallow deer (McElligott et al, 2006), Mongolian gazelle Procapra gutturosa (Frey & Riede, 2003;Frey et al, 2008), goitred gazelle Gazella subgutturosa (Frey et al, 2011;Efremova et al, 2016) and red deer Cervus elaphus (Fitch & Reby, 2001;Frey et al, 2012). Published research so far shows a lack of similar sex dimorphism in vocal anatomy in nonhuman primates.…”

“…Sex dimorphism of vocal anatomy and vocal traits develops under effects of steroid hormones in both humans and ruminants (Lieberman, 1973;Davidson, 2003;Verdonck-de Leeuw & Mahieu, 2004;Frey et al, 2011Frey et al, , 2012Lortie et al, 2015). In male Mongolian and goitred gazelles, the size of the larynx increases remarkably prior to each rut (Frey et al, 2008(Frey et al, , 2012Efremova et al, 2016).…”

Acoustic Structure and Contextual Use of Calls by Captive Male and Female Cheetahs (Acinonyx jubatus)

“…For example, approximately 20% difference in body mass exists between male and female domestic cats [ 46 ], 15% between male and female captive cheetahs [ 8 ] and 22% between male and female wild cheetahs [ 14 ]. Therefore, the vocal apparatus and the sound-producing structures are also expected to be larger for the larger sex [ 47 , 48 ] and their acoustics (the fundamental and formant frequencies) are expected to be lower in the larger sex [ 49 , 50 ]. However, very close or indistinguishable acoustics between vocalizations of the larger and smaller sex were reported for some subspecies of red deer ( Cervus elaphus hispanicus [ 51 ] and C .…”