Purpose: To study social development of born gorilla
infant being mother-raised in a group.
Sampling methods: 1-0 sampling at 60 seconds intervals. Note occurrence
of rough-up, aggressive bite, or crouch by putting initiator-receiver
letter codes.
Ethogram key words: Development.
Infant location relative to other animals:
Contact: In physical contact with mother, whether carried or simply
Other contact: Any physical contact between infant and nonmother.
Proximate: Within arm’s reach of another animal, but only when not in
contact with mother.
Distant: Beyond arm’s reach but less than 15 feet of another animal,
but only when not in contact with mother.
Nursing: Infant’s mouth on mother’s nipple, with or without actual
Eating: Infant puts any solid food (including hay) into its own
mouth, with or without actual chewing or swallowing.
Wean: Mother actively terminates or prevents nursing.
Struggle: Infant trying to break contact with mother while being
restrained by her.
Play: Low intensity slapping, wrestling, or mouthing when initiator
has slack lips or “smile.”
Aggressive behavior:
Rough-up: Slapping, poking, elbowing, punching, hair pulling,
holding, or wrestling, when not in play.
Aggressive bite: Biting, when not in play.
Crouch: Initiator lowers vent rum toward or to substrate, or curls
fatally on substrate.
Copulation: Dorso-ventral mounting or ventro-ventral mounting with
pelvic thrusting. Event terminated when either animal breaks bodily
contact. Note if intromission confirmed (very difficult) or if semen
observed afterward on penis or vagina.
Masturbate: Rhythmic rubbing of genitalia with any part of own body
(e.g., fingers, toe), or against inanimate object.
Hypothesis – Despite decades of debate, it remains unclear whether human bipedalism evolved from a terrestrial knuckle-walking ancestor or from a more generalized, arboreal ape ancestor. Proponents of the knuckle-walking hypothesis focused on the wrist and hand to find morphological evidence of this behavior in the human fossil record Studies, however, have not examined variation or development of purported knuckle-walking features in apes or other primates, data that are critical to resolution of this long-standing debate.
Method – I would like to study more about gorilla knuckle – walking in detail and would like to understand in detail whether it is evolved from human beings.