Recognition of individual neighbors by song in the song sparrow, a species with song repertoires

Abstract

Previous theory and research have suggested that bird species with song repertoires in general, and song sparrows (Melospiza melodia) in particular, cannot readily discriminate between the songs of neighbors and strangers. In a recent study (Stoddard et al. 1991) we showed that song sparrows can in fact discriminate neighbors from strangers on the basis of song. In this study we sought to demonstrate that song sparrows can make the finer discrimination between individual neighbors and that they can do so on the basis of a single song type. We compared the response of territorial males to song playback of neighbors and strangers at three locations : the neighbor's regular boundary, the opposite boundary, and the center of the territory. The birds showed strong neighbor-stranger discrimination at the regular boundary but not at the opposite boundary, nor in the center of the territory. The differences in song discrimination between different boundary locations indicate that song sparrows associate particular songs with particular territories, effectively discriminating between individual neighbors on the basis of song. Song repertoires themselves do not interfere with neighbor recognition to the extent originally postulated. As speakers are moved inside the territory from the border, however, the degree of discrimination diminishes. We believe that differences in speaker placement may have contributed to the variability in neighbor-stranger discrimination observed in previous studies of the song sparrow and perhaps other repertoire species as well. This interpretation is consistent with data from another song sparrow population showing that half the territory takeovers are by immediate neighbors.

Evidence for an audience effect in mice: male social partners alter the male vocal response to female cues

“…However, direct contact with the audience may not be necessary for the audience to be apparent. For example, chemical cues from another male induce changes in the courtship displays of male newts (Lissotriton boscai; Aragón, 2009), birds robustly respond to playbacks of conspecific vocalizations (Stoddard et al, 1991(Stoddard et al, , 1988, and humans behave more generously in an economic game when shown stylized visual cues of an observer (Haley and Fessler, 2005). In our experiments we replaced a male audience with male odor (urine or body odor), playbacks of male USVs or an anesthetized male (mixture of tactile and body odor cues) to test whether any of these cues are sufficient to produce an audience effect.…”

Differential Influence of Frequency, Timing, and Intensity Cues in a Complex Acoustic Categorization Task

“…This held true even when the probe songs were much louder than the training stimuli (while still within naturalistic sound levels) and belies the simple idea that birds automatically generalize singer identity across volumes. One possible explanation for this finding lies in the role of intensity cues in behavior: studies in the field have shown that male birds respond differently to playback of a neighbor's song from different distances and positions (Brooks and Falls 1975a;Naguib and Todt 1998;Stoddard et al 1991). Our training set contained only songs recorded over a relatively narrow range of distances-those a male could reach within a standard laboratory cage.…”

Male great tits eavesdrop on simulated male–to–male vocal interactions

“…This is probably due to the fact that interactions were simulated outside the territory of the focal male (i.e. a centre^edge e¡ect, see Stoddard et al 1991); indeed, levels of approach and post-playback song were lower during the interaction playback than during the assay playback.…”