On production mechanisms of group howling by Canis lupus: A case study

We present early work on the production of howls by Hudson Bay wolves (Canis lupus hudsonicus). During vocalizations, jaw height appears mostly constant at a distinctly lowered position. We computed predicted first formants for a vocal tract length of appropriate size, with a flared oral cavity. Results are consistent with the grey wolves engaging in formant tuning, matching the fundamental frequency of phonation with the first resonant frequency of the vocal tract, amplifying the signal and increasing its loudness.