Relationships in territorial neighborhoods: Factors influencing interactions in a lizard, Anolis sagrei

Date of Award




Degree Name

Doctor of Philosophy (Ph.D.)



First Committee Member

Marion Preest - Committee Chair


Many species of animals exhibit the "dear enemy phenomenon," in which less aggression is shown towards neighbors than towards non-neigbbors. This phenomenon appears in numerous taxa with highly varied social systems. Using males of the territorial lizard, Anolis sagrei, I documented the existence of the dear enemy phenomenon. I then tested among the following hypotheses: (1) that lower aggression towards neighbors is a result of lower threat posed by neighbors; (2) that lowered aggression towards neighbors is a result of benefits to social stability, and (3) that lowered aggression results from prior knowledge of the fighting abilities of neighbors. I conducted an experiment in a naturally established territorial neighborhood. I then created artificial territorial neighborhoods and manipulated social context in a series of field experiments.Anolis sagrei behaved less aggressively towards former neighbors even though neighbors posed a high degree of threat (inconsistent with hypothesis one). They demonstrated reduced aggression towards former neighbors in a neutral arena, suggesting that reduced aggression is a result of more rapid assessment (supporting hypothesis three). The arrival of a new neighbor increased relocations by established neighbors. Although the increase in relocations may have reflected an increase in social instability (supporting hypothesis two), neighbors may have benefited from the instability by gaining territorial space.


Biology, Zoology

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