60 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I46 



time. Female rushes straight toward him. He comes out of box. The two ani- 

 mals sniff at one another's perineal regions. Then the male mounts the female, 

 from the rear. No hesitation or awkwardness. Copulation. Apparently suc- 

 cessful. Lasts at least 20 seconds. Then the male dismounts. No postcopulatory 

 display. Male walks away, female follows. She utters two Low Trills as she 

 does so. 



7 : 44. The two animals sniff one another's perineal regions again. And again. 

 Silent. No Allogrooming or attempts to mount. Then sit side by side. One or 

 both utter (s) a few Squeaks. Then male does begin to groom female. From 

 side. Then mounts her again, from rear. One or both animal (s) utter (s) 

 Squeaks as he mounts. Copulation. Female resists, but not violently. She just 

 turns around to look at male. He dismounts, walks away. Female immediately 

 assumes Arch Posture — and utters a series of Gulps! Then relaxes. Follows 

 male around cage, 7:50. Then both animals retire to sleeping box . . . 



7 : 56. Male is grooming female in box. This is accompanied by lots of sneez- 

 ing by one or both animals . . . 



8:02. Both animals come out of box. Sit side by side, facing in opposite 

 directions. Female utters a few Squeaks. Then male begins to groom her. 

 His movements are gentle. He devotes most of his attention to her lower back 

 and rear. Female continues to utter Squeaks. Goes quite limp while male 

 grooms. Possibly half asleep? Then she suddenly utters loud Squeaks, moves 

 away from male. Goes into box. Male follows, continues Allogrooming in 

 box . , , 



8:17, Female apparently startled or annoyed by something. Bounces out of 

 box, crouches in far corner of cage. Utters long series of Gulps. Male comes 

 out of box, runs toward female, utters one Sneeze-grunt as he does so. Female 

 runs back to box. Performs one burst of Rubbing movements in midst of run. 

 Back into box. Male follows, resumes Allogrooming again , , , 



The following extract illustrates the behavior of an inexperienced 

 male. 



January 28, 1962, O male and C female. This male has been hand reared, 

 in partial isolation, ever since the age of approximately 1^ months. Now full 

 grown. Since being taken from his parents, he has had only brief contacts with 

 other Night Monkeys. He is not familiar with C female. 



7:00 p.m. Female let loose in male's cage, Male leaps away, freezes and 

 crouches in far corner. Female explores cage, uttering Low Trills as she does so. 

 Approaches male. The two animals sniff one another, nose to nose, Male utters 

 Squeaks, Female moves away, resumes exploring with Low Trills, Approaches 

 male again. He sniffs at her perineal region and utters more Squeaks, She 

 moves away again. Explores with Low Trills. Approaches male again. He 

 utters more Squeaks. She moves away again , , . 



7:06. Female approaches male. He suddenly clasps her back, from the side, 

 but does not mount. She breaks away and resumes exploring. Then approaches 

 male again. A vicious fight breaks out. Male apparently the initiator, striking 

 at the female with his hands. Lots of running, chasing, and striking during 

 fight. Both animals quite silent throughout. Then they separate. Male retires 

 to corner and assumes Arch Posture. Female walks around, not very rapidly, 

 uttering many Gulps and a few Sneeze-grimts . . . 



