CONTENTS 



Page 



Introduction 1 



General Habitus, Locomotion, and Feeding 3 



Ordinary Grooming and Cleaning Activities 6 



Hostile Behavior 8 



Overt Attack Behavior 9 



Overt Alarm or Escape Behavior 12 



Display Behavior 15 



Swaying 16 



Silent Arch Postures 18 



Other Visual Patterns 20 



Gruff Grunts 22 



Resonant Grunts 25 



Screams 31 



Low Trills 32 



Moans 36 



Locomotory Notes — Gulps and Sneeze-grunts 38 



Discussion 43 



Social Sniffing 47 



Sexual Behavior and Associated or Related Patterns 48 



Hoots 49 



Rubbing 52 



Copulations, Allogrooniing, and Associated Patterns 54 



Examples 59 



Behavior of Young Animals 63 



Previous Descriptions of Night Monkey Behavior Patterns 78 



Summary 80 



Acknowledgments 82 



Bibliography 82 



ILLUSTRATIONS 

 TEXT FIGURES 



1. Two typical semierect preleaping postures 5 



2. Four head-down postures 15 



3. Arch postures 19 



4. A tj'pical Gruff Grunt, uttered by an adult 23 



5. A relatively short Scream, uttered by an adult 31 



6. Two long Screams, uttered by an adult 32 



7. A Low Trill, uttered by an adult 33 



8. One Moan, followed immediately by one Low Trill, uttered by an 



adult 33 



9. One Sneeze-grimt, followed immediately by one Low Trill, uttered by 



an adult 34 



