Field recordings and playback experiments were conducted on brown thrashers (Toxostoma rufum) in central Massachusetts in order to gather information about the consequences and circumstances of song versatility in this species. The results show the birds to have a large song repertoire in excess of 1,100 song-types or 2,400 figure-types. The pattern of introduction of novel figure-types differed significantly from that predicted from a fixed repertoire model. Some song parameters varied systematically between the two individuals studied and between the different samples of one individual. Brown thrashers in the field responded differently to songs of different versatility but not to songs of different patterns of song parameter variation.
Thompson, Nicholas S., "Song Variety in the Brown Thrasher (Toxostoma Rufum)" (1981). Faculty Works. 69.