Tan and White Color Morphs of White-Throated Sparrows Differ in Their Non-Song Vocal Responses to Territorial Intrusion

Abstract

White-throated Sparrows (Zonotrichia albicollis) occur in two distinct color morphs indicated by the color of the bird's median crown stripe. Tan-striped (TS) and white-striped (WS) sparrows differ in their aggressive behavior, with WS males generally behaving more aggressively than TS males. We measured the number and type of songs and call vocalizations used by TS and WS males in response to simulated territorial intrusion. TS males used significantly more low aggression calls compared to WS males. These results suggest that non-song call vocalizations, in addition to measures of song, may be valuable for future studies of territorial behavior and communication in birds.