Sex Roles in Primate Relatives

Common ChimpanzeesPan troglodytes

• Live in tropical Africa• Have estrus and menstruation • monthly• Females choose mating partners• May form consort relationships

briefly during estrus• Live in matrifocal groups• Mothers nurse for 5 years• Mothers and children have lifelong relationships• Siblings have lifelong relationships

Bonobo Chimpanzees Pan paniscus• Walk upright more• Use sexual behaviors to

comfort or to resolve conflict

• Display all types of homosexual and heterosexual behaviors

• Matrifocal groups• Same lifelong mother-child

and sibling relationships

Bonobo Male Grooming Female

Upright, Bipedal Bonobo Carrying

Sugar Cane

Bonobo Relaxing

Bonobo Female Stretching

Bonobo Intercourse in Missionary Position

Bonobo Intercourse in Missionary Position

Bonobo Females “GG Rubbing”

Bonobo Males

“Rump-Rubbing”

Bonobo Female Masturbating

Bonobo Male Display

Bonobo Baby

Bonobo

Mom and

Baby

Bonobo Mom and

Baby Playing

Bonobo Matrifocal Group