Primates and Primate Behavior

Primates

Primates are a group of mammals that are adapted to living in trees through stereoscopic vision, grasping hands and large brains.

4 Groups

• Prosimians• New World Monkeys• Old World Monkeys• Hominoidea

Primate Evolution

Ethology

• Ethology is the scientific study of animal behavior.

Estrus Cycle

• The majority of primates (like most mammals), have an estrus cycle.

• Females of the species are only receptive to sex when they can conceive.

Chimp in Estrus

Precocial vs. Altricial

• Precocial animals are relatively mature and mobile soon after birth.

• Altricial animals are relatively helpless after birth, requiring extensive care after birth.

Primate Development

• Primates are altricial animals with a requiring a very long period of post-natal dependency.

• Chimps do not reach sexual maturity till they are around 11 (in females) or 13 (in males).

Post-Natal Care

Social Behavior

• Primates are social animals: they live in groups and have complex social behavior.

• Social animals recognize individuals as having differing roles and statuses.

Dominance Hierarchy

• Dominance hierarchy - a structure where the various members of a society differ in power and access to food and mates.

• In a dominance hierarchy, there is competition for who is the Alpha or most dominant individual.

Agonistic Display• An agonistic display is an act that attempts

to intimidate others…without actually attacking them.

Cooperation

• While there is competition between primates, there is much evidence of cooperation as well. Primates will often work together for mutual benefit.

• There is also some evidence for a “sense of fairness” in our primate cousins.

Grooming• Primates can often be seen grooming

each other.

• Allo-grooming refers to grooming of others.

• Auto-grooming refers to grooming of self.

Grooming

Grooming

Grooming

• Grooming serves a variety of functions: it keeps the hair free of dirt and parasites, relieves stress and helps to create and maintain social bonds.

Primate Culture

• Non-human primates can be said to have culture because they have shared practices that are learned…and not just instinctual.

Primate Culture Examples

• Termite fishing• Cracking open nuts with rocks• Gathering water with plant material.

Primate Cognition

• Humans and non-human primates have very interesting similarities and differences when it comes to learning.

• Chimps tend to out-perform humans on memory tests. It is thought that our brains evolved to better use language, while the brains of non-human primates evolved with better short-term memory.

Primate Learning

• All young primates learn by observing adults…

• But humans spend time actively teaching children. And human children have a greater expectation of being taught.