Grooming Behaviors among Wild Bonobos, but Males can not Join it!

Many adult females are grooming each other in this video.
However, males cannot approach to females.

LOBOKO is an adult male (about 25 years old) and has no right-hand fingers.
He is gazing at females enviously.

Bonobo,Wamba,Africa,ボノボ,ワンバ,アフリカ,