THE EFFECT OF HABITAT SOUND PROPERTIES ON ALARM CALLING BEHAVIOR IN TWO SPECIES OF TREE SQUIRRELS (SCIURUS NAYARITENSIS AND SCIURUS ARIZONENSIS)

摘要

Sound attenuation properties of the habitats occupied by two species of tree squirrels affect whether or not the squirrels will make alarm calls. Sound properties have been compared among habitats, microhabitats, weather conditions and seasons. In each case alarm calling activity is consistent with the hypothesis that calling behavior is acted upon by natural selection: calling occurs when squirrel calls carry well, and thus where the potential for communication is high.