Abstract

We conducted a laboratory experiment to determine the influence of familiarity on the aggressive behavior of female red-backed salamanders (Plethodon cinereus) from Virginia. Females that were familiar with each other (i.e., had resided together for five days) spent significantly less time in threat displays toward each other than did females that had not previously encountered each other. These plus previously published data suggest that familiarity among individuals plays a role in social interactions of red-backed salamanders at our research site, where encounters among individuals must be frequent because of a high population density. Reduced aggression with familiarity implies that these salamanders remembered past associations, which would conform to assumptions of the “dear enemy” phenomenon, the “war of attrition” model, and the “fight to learn” hypothesis.