The “perrrck” vocalization of Ruffed Grouse (Bonasa umbellus)

Abstract

The vocal repertoire of Ruffed Grouse (Bonasa umbellus) has been known for decades, but because of the rarity of vocal recordings in the field, few data exist on spectral characteristics of their vocalizations. Here, we provide a spectrogram and analysis of a vocalization rarely heard in the field: the “perrrck” call, which is ~0.5 s in duration and has a fundamental frequency of 613 Hz with several harmonics. We compare this call with the more commonly heard “peet” call, which is much shorter and of higher frequency. Although the function of the perrrck call remains unknown, our analyses show that Ruffed Grouse vocalizations vary in frequency, despite their purportedly weak syrinx