Adaptive: A trait that increases the fitness of the individual who possesses it.

Affiliative: Strong associations among individuals usually manifested by higher rates of proximity and nonaggressive social interactions.

Agonistic: Aggressive and submissive interactions between females and males.

Anthropocentric: Human-focused perspective

Arboreal: Tree-dwelling

Behavioral Adaptation: A behavior that benefits an individual's fitness.

Behavioral Ecology: The study of behavior from and evolutionary and ecological perspective. Adaptive advantages of behaviors under different ecological conditions.

Bipedal: Two-legged locomotion

Brachiation: Arm-over-arm or hand-over-hand propulsion

Callitrichid: Marmosets and tamarins

Canopy: Plant growth that blocks out sunlight; the main layer of trees where their branches and foliage are most dense; all above ground plant organs.

Catarrhine: Old World Monkeys and hominoids

Cathemeral: Active both day and night

Cebid: The New World Monkeys excluding the Marmosets, tamarins, and the atelids.

Ceboid: All New World Monkeys

Cercopithecine: One of the two major divisions of Old World Monkeys.These have cheek pouches.

Cercopithecoid: Old World Monkey with out a grasping tail. Any African or Asian monkey with grasping hands and feet but with out a prehensile tail.

Colobine: The second major division of Old World Monkeys. These have anatomical specializations for digesting leaves.

Demography: The size and composition of groups or populations, as determined by the births, deaths, immigrations, and emigrations of individuals.

Dental Formula: The number of each tooth type in one-quarter of the mouth.

Diurnal: Active during the daylight hours and inactive, or sleeping, at night.

Ecological Niche: The total of a specie's way of living in a particular environment at a particular time.

Egalitarian: Absence of a hierarchy or pecking order. Access to resources is more likely to be determined by who gets to them first than by any other. Attributes of individuals.

Emergent Trees: Trees that tower over the rest of the canopy.

Ethnograms: The repertory of behaviors exhibited by a species.

Fission-Fusion: Societies in which individuals split up into smaller feeding parties.

Fitness: An individual's reproductive success relative to the fitness of other members of the same species.

Folivore: Leaf-eaters

Frugivore: Fruit-eaters

Genotype: The genetic composition of an individual.

Grooming: The removal of dirt, or other objects from the skin or fur, which may be performed by another individual (allogrooming) or by one's self. Allogrooming is considered to be a social activity.

Gumnivore: Feeds on tree gum or sap.

Habituation: The point at which animals cease to alter their behavior in the presence of human observers.

Heritability: A trait that is transmitted in the genes, therefore can be passed along from generation to generation in the descendants.

Hierarchical: A pecking order, usually established through direct contests.

Hominoid: The apes and hominids

Hylobatid: Gibbons and siamangs

Inclusive Fitness: The sum of an individual's fitness and the fitness of all of the individuals relatives, weighted by their degree of relatedness.

Insectivore: Insect-eater

Intraspecific: Within species

Interspecific: Between species

Life History: The total of developmental stages and durations over an individual's life-time. Patterns of development from gestation length, to interbirth intervals, to age at first reproduction, and lifespan that influence the behavior of individuals at different times in their lives.

Local Tradition: Behavior specific to particular to groups or populations that are not always explained by differences in their ecological niches.

Locomotor System: The system by which animals move from one location to another. Primate locomotor systems include vertical clinging and leaping; quadrupedality, brachiation, knuckle-walking, and bipedality.

Matrilocal: Living in the same group as one's matrilineal kin.

Monogamous: A mating system in which one male reproduces exclusively with one female.

Morphology: Anatomical characteristics

Natal: Birth groups

Nocturnal: Active at night

Ontogenetic: When a particular trait or behavior emerges during an individual's lifetime.

Omnivore: Feeds on many different kinds of food both plants and animals.

Patrilocal: Living in the same group as one's patrilineal kin.

Phenotype: The observed characteristics of an individual, often reflecting the effects of environmental conditions on genotypic expression.

Philopatric: Individuals who remain in their natal groups.

Phylogenetic: Evolutionary history; how a particular trait or behavior is distributed across related species.

Platyrrhine: New World Monkeys

Polyandry: A single breeding female and multiple males.

Polygynous: A mating system with a single male and multiple females.

Prehensile: A tail that is capable of grasping objects or substrates, almost like a third hand.

Prosimian: Lemurs, galagos, lorises, and tarsiers

Provisioning: Have designated feeding sites where food is provisioned, but the primates are otherwise free to come and go, or are restricted to large enclosures or islands where they have been introduced.

Proximate: The neural and physiological mechanisms that regulate behavior.

Quadramanous: A locomotory style that involves the use of all four limbs; usually associated with slow, deliberate climbing.

Quadrupedal: A locomotory style that involves the use of all four limbs.

Savanna: Tropical grassland

Semiterrestrial: Primates that spend significant proportions of their time on the ground.

Sexual Dimorphism: Morphological differences between the sexes.

Sociobiology: Biological study of social behavior.

Socionomic Sex Ratio: The ration of the number of breeding females to males in a group.

Strategy: Behavior or behaviors that increase individual fitness, and therefore are favored by natural selection.

Suspensory: A locomotor or postural style involving swinging or hanging from arms.

Terrestrial: Ground-dwelling

Territorial: Primates that defend the entire resource area they exploit from intrusions by other members of their species.

Ultimate: Adaptive significance of a trait.

Understory: The area below the trees but above the ground.