Vocal Communication in Raccoons (Procyon Lotor)

Abstract

AbstractThe study describes structure, ontogeny and contexts of raccoon (Procyon lotor) vocalizations and investigates whether structure and motivation interplay in the way predicted by general motivation-structural rules (MORTON, 1977, 1982). Observations during a full reproductive cycle in a mixed group of captive raccoons indicate that they use an elaborate vocal repertoire including 13 calls (Table 1). Two calls are tonal (whistle, squeal), three noisy (snort, bark, growl); four have a mixed structure (cry, screech, gecker, grunt) and four have pulsed syllables (chitter 1, chitter 2, churr, purr). Though some calls grade into one another, the repertoire is largely discrete. Three calls are present at birth and form the nestling repertoire. The adult repertoire gradually develops through the time of weaning (Fig. 2). Several calls are characteristic for the sexual and parental phase. Most calls are associated with one or a few contexts (Table 2). Four calls are utilized by animals while distressed and have an attracting effect on others. Four calls express hostile motivation and repel other animals. Five calls are used by animals approaching another or having body contact; they serve in promoting or maintaining contact. Calls used in similar contexts show remarkable structural similarities. Distress calls are tonal or mixed, hostile calls noisy in accordance with motivation-structural rules. Contact calls deviate in being noisy and low in basic frequency. Possible reasons are discussed. A comparison of the vocalizations in other carnivores reveals that the structure-motivational pattern found in raccoons is a wide-spread phenomenon in carnivores.