Stranger danger: A meta-analysis of the dear enemy hypothesis

<p>The dear enemy hypothesis predicts that territorial individuals will be less aggressive toward known neighbors than to strangers. This hypothesis has been well studied and there is a wealth of data demonstrating its prevelance among some taxa. However, a quantitative synthesis is needed to test the generality of the phenomenon, identify key mechanisms driving the behavior, and guide future research. Here we made a comprehensive collection of Dear Enemy data from 138 studies representing 105 species spread over eight taxonomic classes. The associated paper finds that Dear Enemy is a common phenomenon but drivers of this phenomenon are still understudied and current knowledge is unable to disentangle competing hypotheses of drivers of this behavior.</p>