NO. 5 BEHAVIOR OF THE NIGHT MONKEY — MOYNIHAN 55 



Apart from this, the female seems to remain essentially passive 

 throughout the whole performance. Both individuals generally are 

 silent throughout. The whole performance seldom or never takes more 

 than a couple of minutes. Sometimes it is much briefer. There is no 

 regular postcopulatory display ; although it is not uncommon to see 

 a female sniff at the male's perineal region, briefly, immediately after 

 he dismounts. 



Simple and rapid copulations of this type seem to be performed 

 only when both the male and female are highly motivated and 

 thoroughly familiar with one another. 



A pattern frequently associated with less simple copulation attempts 

 is Allogrooming. One of the individuals grooms the other, or they 

 groom one another mutually. When only one individual performs 

 Allogrooming, it may be either the male or the female. It is usually 

 the male when the Allogrooming occurs in very close association with 

 apparently successful copulation attempts. The form of the Allo- 

 grooming movements seems to be the same in both sexes. 



One individual wishing to groom another generally begins by 

 sniffing. The "groomer" usually sniffs most attentively at the sides, 

 armpits, or perineal region of the "groomee." The actual grooming 

 follows immediately after the sniffing. It is accomplished by use of 

 both hands and teeth. The use of the teeth seems to be most important 

 in Allogrooming (unlike autogrooming) . The grooming individual 

 nibbles at the fur and/or skin of the individual being groomed, pre- 

 sumably separating matted hairs, removing dead hairs and patches of 

 dead sloughed skin, and also any small arthropods that may be 

 present (both ticks and chiggers are common, at times, on Barro 

 Colorado). The hands are used both to "curry" or comb the fur of 

 the individual being groomed and, even more frequently, to separate 

 the fur so that the grooming individual can get at the base of the 

 hairs and the skin with its teeth. During some Allogrooming, the 

 groomer uses its hands to push or pull the groomee into a position 

 or posture to facilitate the grooming. 



The groomer may groom any and all parts of the groomee, in 

 almost any sequence; but it usually devotes most of its attention to 

 the sides, back, crown and back of the head. The two animals gen- 

 erally sit side by side during Allogrooming, facing in the same or 

 opposite directions, and the groomer reaches the groomee from the 

 side and/or the rear (see figure 14). 



Allogrooming may lead to mounting. This "grooming mounting" 

 may intergrade with the type of mounting that occurs during copula- 

 tions, and intermediate performances are common, but in its typical 



