Vocal activity of the red deer and the acoustic structure of its rutting calls in the Russian Far East

Vocal phenotype of male rutting roars and genetic markers delineate East European red deer (Cervus elaphus) from Central and West European populations

This study investigates a population of red deer Cervus elaphus, founded by 10 individuals introduced in the nineteenth century from Germany to the Voronezh region of the European part of Southern Russia and then developed without further introductions. We characterize for the first time the vocal phenotype of the Voronezh red deer male rutting calls in comparison with similar data on the Pannonian (native Central European) and Iberian (native West European) red deer obtained by the authors during preceding studies. In addition, we provide for the first time the genetic data on Pannonian red deer. In Voronezh stags, the number of roars per bout (2.85 ± 1.79) was lower than in Pannonian (3.18 ± 2.17) but higher than in Iberian (2.11 ± 1.71) stags. In Voronezh stags, the duration of main (the longest within bouts) roars was longer (2.46 ± 1.14 s) than in Pannonian (1.13 ± 0.50 s) or Iberian (1.90 ± 0.50 s) stags. The maximum fundamental frequency of main roars was similar between Voronezh (175 ± 60 Hz) and Pannonian (168 ± 61 Hz) but higher in Iberian stags (223 ± 35 Hz). Mitochondrial cytochrome b gene analysis of red deer from the three study populations partially supports the bioacoustical data, of closer similarity between Voronezh and Pannonian populations. In contrast, microsatellite DNA analysis delineates Voronezh red deer from either Pannonian or Iberian red deer. We discuss that population bottlenecking might affect the acoustics of the rutting roars, in addition to genotype.

Acoustic parameters of courtship and human-directed friendly vocalisations in seven species of Neotropical deer in captivity

Context Polygynous deer rut vocalisations have been found to be highly conspicuous, typical of the species and important in sexual selection. Information about vocalisations is not available for Neotropical species (subfamily Odocoileinae). Aims The objective was to record courtship vocalisations from all Neotropical deer available, looking for differences among species useful for taxonomic identification, characterise the vocalisations according to acoustic parameters and to try to determine functions. Methods Four species of brocket deer (red, Mazama americana (n = 9); grey, M. gouazoubira (n = 7); Amazonian brown, M. nemorivaga (n = 3); Brazilian dwarf, M. nana (n = 1)), and one individual each of marsh (Blastocerus dichotomus), white-tailed (Odocoileus virginianus) and taruca (Hippocamellus antisensis) deer were recorded in captivity at two institutions, in conditions of courtship or human interaction. The acoustic analysis was performed with Praat. Data from the first three species of Mazama were analysed statistically with a multilevel model with two layers. Key results In the context of courting either females or humans, male deer produced low-intensity, short-duration (0.1–0.3 s) bleats with fundamental frequencies (F0) between 100 and 400 Hz; calls were similar among species. The duration of these calls for Amazonian brown brocket males was significantly longer than for males of the other two species. Females of two species had longer-duration calls than did males, in friendly interactions with humans. F0 differences among species for both friendly and courtship calls were almost significant for males of M. gouazoubira. Individual differences were highly significant for both duration and mean F0. Mean F0 for courtship calls of adult males was not correlated with body size in six of the seven species, in contrast to the theory of acoustic allometry. Conclusions The production of male courtship bleats is probably a basic feature of Odocoiline deer and is probably important in sexual selection and female choice. The differences from one species to another are not sufficient for taxonomic use but may be incipient isolating mechanisms between grey and Amazonian brown brocket deer. Implications Studies of deer vocalisations have shown their importance in sexual selection and their incredible variety in closely related species and subspecies, but they have dealt mainly with Old World deer. This study fills a gap in our knowledge, as the first on Neotropical deer, which constitute six genera and 17 species and are widely distributed in the Americas. These data are important for future studies on the function and phylogeny of deer vocalisations.

Remarkable vocal identity in wild-living mother and neonate saiga antelopes: a specialization for breeding in huge aggregations?

Saiga antelopes Saiga tatarica tatarica give birth in large aggregations, and offspring follow the herd soon after birth. Herding is advantageous as anti-predator strategy; however, communication between mothers and neonates is strongly complicated in large aggregations. Individual series of nasal and oral contact calls of mother and neonate saiga antelopes were selected from recordings made with automated recording systems placed near the hiding neonates on the saiga breeding grounds in Northern Kazakhstan during synchronized parturitions of 30,000 calving females. We used for comparison of the acoustic structure of nasal and oral contact calls 168 nasal calls of 18 mothers, 192 oral calls of 21 mothers, 78 nasal calls of 16 neonates, and 197 oral calls of 22 neonates. In the oral calls of either mothers or neonates, formant frequencies were higher and the duration was longer than in the nasal calls, whereas fundamental frequencies did not differ between oral and nasal calls. Discriminant function analysis (DFA) based on six acoustic variables, accurately classified individual identity for 99.4% of oral calls of 18 mothers, for 89.3% of nasal calls of 18 mothers, and for 94.4% of oral calls of 18 neonates. The average value of correct classification to individual was higher in mother oral than in mother nasal calls and in mother oral calls than in neonate oral calls; no significant difference was observed between mother nasal and neonate oral calls. Variables mainly responsible for vocal identity were the fundamental frequency and the second and third formants in either mothers or neonates, and in either nasal or oral calls. The high vocal identity of mothers and neonates suggests a powerful potential for the mutual mother-offspring recognition in dense aggregations of saiga antelopes as an important component of their survival strategy.