Social information trumps vegetation structure in breeding-site selection by a migrant songbird

Abstract

To maximize fitness, organisms must assess and select suitable habitat. Early research studying birds suggested that organisms consider primarily vegetation structural cues in their habitat choices. We show that experimental exposure to singing in the post-breeding period provides a social cue that is used for habitat selection the following year by a migrant songbird, the black-throated blue warbler (Dendroica caerulescens). Our experimental social cues coerced individuals to adopt territories in areas of very poor habitat quality where individuals typically do not occur. This indicates that social information can override typical associations with vegetation structure. We demonstrate that a strong settlement response was elicited because post-breeding song at a site is highly correlated with reproductive success. These results constitute a previously undocumented, but highly parsimonious mechanism for the inadvertent transfer of reproductive (public) information from successful breeders to dispersers. We hypothesize that post-breeding song is a pervasive and reliable cue for species that communicate vocally, inhabit temporally autocorrelated environments, produce young asynchronously and/or abandon territories after reproductive failure.

Social cues are preferred over resource cues for breeding-site selection in Barn Swallows

“…Birds have been shown to gather information about the presence and breeding performance of conspecifics during the breeding season to select a suitable breeding site in the following year (Pärt and Doligez 2003;Parejo et al 2007;Betts et al 2008b). However, the number of breeding pairs and breeding success provide information about the presence and breeding performance of conspecifics for a single year only, whereas undamaged old nests may provide information from several years.…”

Experimental identification of social learning in wild animals

“…Several field studies, by manipulating the social environment, have focused on the role of key individuals in effecting changes in the behavior of (Betts, Hadley, Rodenhouse, & Nocera, 2008). The effect of social information (decoys and playbacks) was compared with a control condition (silence), with the social information presented one year and settlement decisions assessed the next.…”

Juvenile sparrows preferentially eavesdrop on adult song interactions

“…It is hypothesized that young birds may even learn to recognize dangerous predators by listening to the mobbing vocalizations of other birds (Curio 1978). There is also recent evidence that individuals eavesdrop on the conspicuous songs of birds, both to gain information about suitable breeding sites (Doligez et al 2002;Dall et al 2005;Betts et al 2008) and to assess characteristics of specific individuals. For example, eavesdropping on singing interactions may allow females to assess the quality of a potential mate (Otter et al 1999;Mennill et al 2002;Kunc et al 2006) or males to assess the aggression level or dominance rank of a potential competitor (Peake et al 2001;Mennill & Ratcliffe 2004).…”