Rutting roars in native Pannonian red deer of Southern Hungary and the evidence of acoustic divergence of male sexual vocalization between Eastern and Western European red deer (Cervus elaphus)

Abstract

The acoustics of male rutting roars, aside from genetic markers, are useful tools for characterization of populations and subspecies of red deer Cervus elaphus. This study of rutting mature male Pannonian red deer from Southern Hungary presents a description of the calling posture, a graphical reconstruction of the oral vocal tract length during rutting roar production and a spectrographic analyses of 1740 bouts containing a total of 5535 rutting roars. In addition, this study provides the first direct comparison of the bouts and main (=longest) rutting roars between Pannonian and Iberian red deer stags, representative of the Western and Eastern lineages of European red deer. The bouts of the Pannonian stags comprised 1–15 roars per bout; 24.37% were single-roar bouts and 23.68% were two-roar bouts. The duration of the main roars within bouts ranged from 0.52 s to 4.60 s, 1.13 ± 0.50 s on average. Main common roars (66.3% of the 1740 main roars), were longer than harsh roars (1.27 ± 0.55 s vs 0.87 ± 0.25 s) and higher in maximum fundamental frequency (179 ± 61 Hz vs 147 ± 54 Hz). In multi-roar bouts, main harsh roars were first roars in 47.4%, intermediate roars in 19.2% and last roars in 18.8% of the bouts. Bout structure and the acoustics of main roars in the Pannonian stags differed from those in the Iberian stags and in stags from other populations of Cervus elaphus. These results support the power of rutting vocalizations for consideration as an additional tool for discriminating populations and subspecies within Cervus elaphus.