Oral Groom Solicitation and Finger Sucking

The capuchins at Curu have interesting social traditions that I call oral grooming solicitation and finger sucking.  This behavior was not seen prior to the 1993 field season.  During 1993 I observed two older individuals-- Mr. Burns and Bette-- soliciting this behavior from juveniles and subadults.  Today,  the behavior is now seen among individuals of all age and sex classes.  

Here's what happens:  The solicitor would place a piece of bark, leaf or fruit in his mouth and sit with his mouth slightly parted.  The interacting subject would then attempt to remove the object from the solicitor's mouth.  Dental grooming involves muzzling and mouth to mouth contact which sometimes looks like kissing in addition to the use of fingers.  The groomer may sit with her fingers in the solicitor's mouth for a few seconds to several minutes.  Often, when the interacting subject removes the object, the solicitor will take hold of the groomer's hand with the object and replace it into his mouth.  Sometimes they sit for lengthy periods while the solicitor just holds the groomer's hand with the object.  Or, the solicitor might gently take the object away from the groomer and replace in her own mouth, thus soliciting the entire sequence again.  The entire time, both individuals avoid eye contact and stare off into space in a dazed manner, unlike that seen in any other behavior type

Here are Bud and Angelo, two low-ranking young adult males.  Angelo has put a small piece of bark in his mouth and has been sitting with his lips slightly parted. Bud is holding Angelo's nose and lower jaw,  opening Angelo's mouth wider.  Angelo has put his hand up to Bud's to prevent Bud from removing the bark from his mouth.

 

Bud has inserted his fingers into Angelo's mouth and is attempting to remove the piece of bark.  Angelo has is holding Bud's hand and fingers so that they remain at his mouth.  For several minutes he will continue to suck on Bud's fingers and hold Bud's hand so he cannot remove the bark.  

 

Bud now has the bark in his hand.  Without looking at him, Angelo is taking it away from Bud.  If he gets it back, Angelo will replace the bark in his mouth to solicit more of the same behavior from Bud.  Bud will again try to take the bark, leaving his fingers in Angelo's mouth.  This sequence can repeat over and over, and last more than 45 minutes.

See video of this sequence

click   HERE

and scroll to the last example under "Games"