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Overproduction of acid in the blood and body tissues. 

Activity Budget:  
A way to quantify animal behavior by observing an animal over an extended period and documenting activity.

Affiliative behaviors:
Social interactions that function to reinforce social bonds with a group or which are of mutual benefit to all animals involved in the interaction.

Afro-Eurasian monkeys:
Also called “African-Eurasian” monkeys. Monkeys native to Gibraltar, Africa, and south Asia. This term replaces “Old World monkeys”.

Of, relating to, or being aggressive, or defensive social interaction (such as fighting, fleeing, or submitting) between individuals usually of the same species.

Alarm call:
Specific calls that individuals in a troop make to warn other members of their group of imminent danger, such as predators.

All-male group/unit (AMU):
A social group consisting exclusively of males, usually occurring in species with one-male groups or multi-level societies (i.e., social systems in which single males monopolize several females and there are extra males without females).

Also known as “alloparenting,” individuals other than the biological parents temporarily care for other’s infants.

Social grooming within a species.

Individuals other than the biological mother of an offspring perform the functions of a mother (as by caring for an infant temporarily).

Nursing by a female other than the biological mother.

An individual other than the biological parent of an offspring who performs the functions of a parent (as by temporarily caring for an infant).

Allopatric speciation:
Also referred to as geographic speciation is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow.

Alpha male:
The dominant male animal in a particular group.

Infants of a species who are still not fully developed, and must be cared for by their parents. 

Behaviors performed by an animal that benefits another individual at their own expense. 

American monkeys:
Monkeys native to southern Mexico, Central, and South America. This term replaces “New World monkey.”

Relating to the anus and genital region.

Describes a concept called “anthropomorphism,” the attribution of human traits, emotions, and other human characteristics to non-human beings, including animals and plants.

Environmental disturbance or environmental pollution originating in human activity. 

Physically adapted to living primarily or exclusively in trees.

An expanse of water with many scattered islands; a group of islands.

Not occurring during or limited to a particular season: not seasonal.



A layer of social structure in the multi-level societies of some monkeys that consists of multiple one-male units and generally remains relatively cohesive over space and time, analogous to the group or troop of other monkeys.

Basal Metabolic Rate (BMR):
The number of calories you burn as your body performs basic (basal) life-sustaining function.  

Binocular vision:
Both eyes are forward-facing and have overlapping visual fields to produce a single, three-dimensional image.

Binomial nomenclature or binary nomenclature:
A formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages.

The level of variation of life in an ecosystem, a biome, or the entire planet. Biodiversity is a measure of the health and function of an ecosystem.

Biodiversity hotspot:
A biogeographic region with significant levels of biodiversity that is under threat from humans.

A large naturally occurring community of flora and fauna occupying a major habitat, e.g. forest or tundra. 

An animal that walks on two legs. 

Walking on two legs.

Birth interval:
The time between pregnancies or births. 

Also called arm swinging, a form of arboreal locomotion in which primates swing from tree limb to tree limb using only their arms.

A movement that stretches the body across a spatial gap while holding onto opposing branches.

Broadleaf forest:
Also referred to as a temperate forest or mixed forest, comprised primarily of deciduous, coniferous, and evergreen trees. These forests are richest and most distinctive in central China and eastern North America.

Meat from wildlife species that are hunted for human consumption, generally in tropical forests.



A pouch that is considered to be the beginning of the large intestine.

A large volcanic crater.

A mammal of the dog family.

Beneath the emergent layer, the canopy layer is the primary layer of the forest and forms a roof over the two remaining layers (the understory and forest floor). Many animals live in this maze of leaves and branches, where food is abundant.

The dead body of an animal. 

The decaying flesh of dead animals. 

An animal that feeds on flesh.

Irregularly active during night or day, dawn or dusk, depending on environmental circumstances.

Re-ingesting feces in order to further break down the cellulose in leaves.

Molecule found in plant matter that gives structure and strength to the cell walls of plants and provides dietary fiber.

Cheek Pouches:
Pockets on the side of the head between the jaw and the cheek that some animals have to store food.

A group of animals derived from a common ancestor species.

A taxonomic group comprised of organisms (animals) that share a common attribute. It is further divided into one or more orders.

Cloud forest:
A forest that contains a persistent or seasonal presence of low level clouds and mist. 

Members of the subfamily Colobinae.

A subfamily of the Old World monkey family that includes 61 species in 11 genera.

Colonizing forest:
Refers to the process by which trees colonize new ground from existing local sources. This natural colonization occurs through seed dispersed by birds, mammals, wind, or gravity, or by vegetative colonization where new growth sprouts from the stem or roots of adjacent trees. Wildlife biologists regard species colonization of a new habitat patch as an efficiency indicator of biodiversity conservation.

Living in close association in a way that allows one species to benefit without harming the other.

A thing or person of the same kind or category as another.

A type of tree that produces cones and evergreen needles.

Belonging to the same species.

Contact call:
Conveys an individual’s location to other members of a group while foraging for food.

Cooperative breeding:
A social system characterized by alloparental care wherein offspring are cared for by other members of the group in addition to their parents.

To have sexual intercourse. 

Appearing or active in twilight.

In ecology, the ability of an animal to avoid observation or detection by other animals through methods such as camouflage, nocturnality, subterranean lifestyle, and mimicry.

Cultivated areas:
Agricultural areas of land that are harvested every year. 

Cutaneous scent gland:
Any specialized skin gland that allows an animal to emit odors as sexual or defensive signals. 


Deciduous Forest: 
Forests that change seasonally. The word deciduous means to fall off at maturity. The opposite of deciduous is evergreen.

The permanent cutting, clearing, and removal of trees to convert forest land for other use, such as pasture, cropland, or plantations.

The process by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture.

The arrangement or condition of the teeth in a particular species or individual. 

A type of sexual dimorphism relating to a species exhibiting two colors; the male may be one color and the female another.

Dichromatic vision:
A form of color vision in which only two of the primary colors are perceived.

Term used to indicate a mammal that walks on its toes while its heels do not touch the ground, like dogs or cats.

Occurring in two distinct forms.

Dipterocarp forest:
Prevalent in Asian tropical rainforests, trees of the family Dipterocarpaceae; regarded as economically valuable timber resources and, therefore, vulnerable to clearcutting.

Disjunct distribution:
Geographically fragmented distribution of animals of the same species at considerable distance.

Distal end:
Situated away from the point of attachment or origin or a central point.

Disturbed Habitat:
A temporary change in environmental conditions that causes a pronounced change in an ecosystem.

Disturbed secondary forest:
Disturbances refer to events that upset a habitat resulting in substantial impact. 

Active during daylight hours.

Dominance hierarchy:
A type of social hierarchy that arises when members of a social group interact, often aggressively, to create a ranking system. In social living groups, members are likely to compete for access to limited resources and mating opportunities. 

Of, on, or relating to the upper side or back of an animal, plant, or organ.

The back part of an organism or structure.


The branch of biology that deals with the relations of organisms to one another and to their physical surroundings.

A major ecosystem; a large unit of land or water containing a geographically distinct assemblage of species, natural communities, and environmental conditions.

A biological community of interacting organisms and their physical environment.

A region of transition between two biological communities.

Emergent layer:
The tallest trees in a forest are known as emergents, towering as much as 200 feet above the forest floor with trunks that measure up to 16 feet around. Most of these trees are broad-leaved, hardwood evergreens.

Intrusion on an animal’s territory.

Native or restricted to a certain area or country.

Dispersal of spores or seeds by animals after passage through the gut.

A substance produced by a living organism, which acts as a catalyst to bring about a specific biochemical reaction.

A plant that grows on the surface of another plant or tree but gets its nutrients from the air, rainfalls, and compost from the plant it rests on.

​Of, relating to, or being the person or thing for whom or which something is named.

The recurring reproductive cycle in many female mammals, including estrus, ovulation, and changes in the uterine lining.

A recurring period of sexual receptivity and fertility in many female mammals.

An external supportive covering of an animal (such as an arthropod).

Ex situ conservation:
Conservation actions that occur outside of the species’ natural habitat, such as captive breeding programs in zoos.

Currently or already existing or living. 

Extent of occurrence:
A parameter that measures the spatial spread of the areas currently occupied by the taxon. The intent behind this parameter is to measure the degree to which risks from threatening factors are spread spatially across the taxon’s geographical distribution. It is not intended to be an estimate of the amount of occupied or potential habitat, or a general measure of the taxon’s range.

When a species ceases to exist in a geographic area they once occupied.

Extractive foraging: 
The act of finding and processing food sources found embedded in the ground, sometimes with the aid of tools.

To force or press out.

A substance, such as gum, sap, or resin, which flows from the vascular system of a plant.

Eye shine:
The reflection of light off a membrane within the eyes of certain animals (but not human animals) that facilitates supreme night vision and causes their eyes to shine in the dark.



A taxonomic group of one or more genera, especially sharing a common attribute.

A mammal of the wild cat family.

Fission-fusion society:
A society in which the members of a social group break off into smaller groups and then rejoin as a larger group.  

Thick pads of flesh that frame the face and develop more prominently in dominant male orangutans. Some less dominant males never develop cheek flanges. 

Flagship species:
A species selected to act as an ambassador, icon, or symbol for a defined habitat, issue, campaign or environmental cause.

Flora and fauna:
Plants and animals.

Having a lot of leaves.

Of or relating to flowers, a flora, or the study of plants and plant groups.

Feeding on flowers.

An animal who primarily eats leaves.

Having a diet that consists of leaves.

Foregut fermentation
A form of digestion that occurs in the foregut of some animals.

Forest floor:
The fourth and bottom layer of the forest. It’s very dark and almost no plants grow in this area as a result.

Fraternal Twins:
Twins that develop from two different eggs.

An animal who feeds on fruits.

Having a diet that consists of fruits.

The ability to produce live offspring. 


Gallery forest: 

A forest that serves as a corridor along rivers or wetlands and projects into landscapes that are otherwise sparsely treed, such as savannas, grasslands, or deserts.

A method of managing forested areas or land in order to preserve it and protect the species it inhabits from poaching or illegal logging. A gazetted forest is a protected forest.

Gender dimorphism:
Distinct difference in size or appearance between the sexes of an animal, in addition to difference between the reproductive organs themselves, but only during certain seasons.

Gene flow:
The transfer of genes from one population into another through breeding.

Generation time:
The average time between successive generations in a population.

Genetic bottleneck:
When a species’ population is reduced in size (i.e. by a cataclysmic event, habitat fragmentation, etc.) limiting the genetic diversity of the species.

Genus (plural, genera):
A biological classification, or ranking, of living beings that includes a group(s) of species that are structurally similar or “related” to one another through evolution.

The intentional practice of eating earth or soil-like substances such as clay, chalk, or termite mounds.

Gestation Period:
The time of pregnancy from conception until birth. 

Slender, thin.


Herbivorous animal who feeds on grasses.

Having a diet that consists of seeds.

Guard hairs:
In some mammals, long, coarse hairs that protect the softer layer of fur below.

A class of omnivores whose main diet is tree gum, sap, and resin with bugs for protein. 

Gut Microbes:
Bacteria that live in the intestinal tract. 


Habitat fragmentation:

The process by which a large, continuous stretch of habitat gets divided into smaller, disjointed patches of habitat.

The innermost digit of the foot, known for humans as “the big toe.”

Sometimes spelled Haplorrhini. Dry-nosed primates (from the Greek for “simple-nosed”), a suborder of primates containing the tarsiers, Old World monkeys, apes, and New World monkeys.

A group of females guarded by a male, who prevents other males from mating with them; an animal group consisting of one or two males, a number of females, and their offspring.

An animal that feeds on plants.

Anatomically and physiologically adapted for eating plant material (e.g., foliage is the main component of one’s diet).

A system of organization in members of a group who are ranked one above the other according to status or authority.

The tendency of a system, especially the physiological system of higher animals, to maintain internal stability, owing to the coordinated response of its parts to any situation or stimulus that would tend to disturb its normal condition or function. Any self-regulating process by which biological systems tend to maintain stability while adjusting to conditions that are optimal for survival.

The state of having the same or similar relation, relative position, or structure.

The offspring of two plants or animals of different species or varieties.

The act or process of mating organisms of different varieties or species to create a hybrid.

A U-shaped bone in the neck that supports the tongue.



The breeding of closely related individuals, especially over many generations.

Inbreeding depression:
A reduction in the overall health and reproductive fitness of a population due to inbreeding.

Narrow-edged teeth at the front of the mouth, adapted for cutting.

Originating or occurring naturally in a particular place; native.

The killing of young offspring by a mature animal of the same species.

Infant parking:
Refers to mothers leaving their young alone in the nest at night.

A diet that is compromised of feeding on insects, worms, and other invertebrates. 

Interbirth interval:
Refers to the period of time between successive births of an individual female.

Intrasexual selection:
When members of the same sex (within a species) compete with each other in order to gain opportunities to mate with others (e.g., male against male competition for females).

Produced, occurring, or existing within a species or between individuals of a single species.

Produced, occurring, or existing between individuals of different species.

​Ischial callosities:
A thickened piece of skin found on the buttocks of animals.

​International Union for Conservation of Nature.

Invasive species:
Also called introduced species, alien species, or exotic species; any nonnative species that significantly modifies or disrupts the ecosystems it colonizes.

An animal without a backbone (spine), including arthropods, mollusks, myriapods (such as earthworms, leeches, millipedes, and centipedes), sea anemones, and corals.



One of a family of fibrous structural proteins. It is the key structural material making up hair, nails, feathers, horns, claws, hooves, and the outer layer of skin. Keratin is also the protein that protects epithelial (skin) cells from damage or stress.

The process by which vertebrate epithelial (skin) cells become filled with keratin protein filaments, die, and form tough, resistant structures such as skin, nails, and feathers.

A taxonomic category of the highest rank, such as Animalia, grouping together all forms of life having certain fundamental characteristics in common.



The secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young.

Lesser apes:
A classification ranking within the biological order of primates, beneath great apes and above higher primates and prosimians.

An animal that feeds on wood.

A family of slim arboreal strepsirrhine primates (i.e. primates with a wet nose) found in tropical Africa and Southeast Asia. 

Lowland forest:
An equatorial evergreen rainforest, commonly known as a tropical rainforest, which receives high rainfall (80 in; 2 m) throughout the year.



Plural: mammae. A milk-secreting organ of female mammals.

A mangrove refers to two different things: a tidal swamp ecosystem found in tropical deltas, estuaries, lagoons, or islands, and the characteristic tree species populating this ecosystem. Mangrove trees have developed unique adaptations to the harsh conditions of coastal environments.

Mate guarding:
The physical guarding of a female in order to deny rival males the opportunity to mate with her.

Mating plug:
A gelatinous secretion deposited into the female genital tract after copulation to facilitate successful fertilization.

Familial relationships that can be traced through a female.

Matrilineal Society: 
Based on a line of descent through the female. Offspring are traced back to the mother as opposed to a patrilineal society, from which descent is traced to the male. 

Mean temperature:
The average temperature of the air as indicated by a properly exposed thermometer during a given time period, usually a day, a month, or a year. For climatological tables, the mean temperature is generally calculated for each month and for the year.

A small, localized habitat within a larger ecosystem, such as a tree stump, having conditions that sustain a limited range of animals and plants.

Miombo woodland
An ecoregion of central and southern Africa consisting of grassland, savanna, and shrubland, named for the miombo tree.

Mitochondrial DNA:
Genetic characteristics passed on by the mother to her offspring.

Mixed deciduous forest:
A forest that has adapted to seasonal shortages of water; a small proportion of trees are evergreen but the majority are to some extent deciduous (that is, they shed their leaves) during the dry season.

Having only one male partner over a period of time.

A mating system in which a male and female mate exclusively with each other.

Having only one sexual partner. 

Showing no difference between the two sexes other than their genitalia

Having only one type or representative, especially (of a genus) containing only one species. 

Relating to a mountainous region of relatively moist, cool upland slopes below timberline dominated by large coniferous (evergreen) trees.

Montane forest:
A forest that grows on the slope of a mountain, regardless of altitude or latitude, within a specific climate, just below the subalpine zone.

A local population of a species that consists of interbreeding animals and is distinguishable from other populations by morphology or behavior though capable of interbreeding with them. In zoology, a visual or behavioral difference between organisms of distinct populations in a species.

Refers to a living organism’s distinct physical (biological) characteristics.

A branch of biology that deals with the form and structure of animals and plants.

Multi-male multi-female group/unit (MMU): 
A social group consisting of multiple adult males and multiple adult females.

“Million years ago”, a science-related unit of time.


Natal group:

The group into which an animal is born.
Relating to, or constituting the tropical New World biogeographic region that extends south, east, and west from the central plateau of Mexico.

New World monkey:
Monkeys native to southern Mexico, Central, and South America. This term is becoming passe in favor of “American monkeys.”

In biology, the niche of an organism is the functional role that it plays within an ecosystem.

Niche partitioning:
The sharing of resources by species to avoid competition.

Nictitating membrane:
A whitish or translucent membrane that forms an inner eyelid in birds, reptiles, and some mammals. It can be drawn across the eye to protect it from dust and keep it moist.

Active at night.

Nominate subspecies:
In zoological nomenclature, when a species is split into subspecies, the originally described population is retained as the “nominotypical subspecies,” which repeats the same name as the species.

Nonprehensile or Non-prehensile:
Incapable of grasping or gripping.

A subtle difference or distinction in expression, meaning, response, etc.


Old World monkey:

Monkeys native to Africa and Asia. This term is becoming passe in favor of “Afro-Eurasian monkeys.” 

Having a diet that consists of food of both plant and animal origin.

An animal or person who eats food of both plant and animal origin.

One-male group/unit (OMU)
A social group consisting of one adult male and multiple adult females.

Opposable thumb:
A thumb that can be placed opposite the fingers of the same hand. Opposable thumbs allow the digits to grasp and handle objects and are a characteristic of primates.

A taxonomic rank, such as “primates,” used in classifying organisms, generally below the class and comprised of families sharing a set of similar nature or character.

The release of the ripe egg (ovum) from the ovary. 


Palm swamp:

Palm swamps are formed in low, seasonally inundated flat areas with poor drainage and are characteristic of the Amazon Basin.

Pertaining to the palm.

A term used to indicate that an animal puts the whole foot—with the sole—on the ground to walk.

An organism that lives on or in an organism of another species, known as the host, from the body of which it obtains nutriment.

Refers to mothers leaving their young alone in the nest while she forages.

Digital bones of the hand or foot: that is, fingers or toes. 

Paternal care:
Paternal care is parental investment provided by a male to his own offspring, such as carrying, providing food, or protection.

The fur, hair, or wool of a mammal.

The observable (physical and psychological) characteristics of an organism from both genetics and environment.

A chemical that an animal produces that changes the behavior of another animal of the same species.

Returning to one’s birthplace or remaining with one’s birth group.

The study of phylogeny to classify and identify organisms.

Phylogenetic tree:
A diagram that represents evolutionary relationships among organisms.

The history of the evolution of a species or group, especially in reference to lines of descent and relationships among broad groups of organisms.

Erection or bristling of hairs due to the involuntary contraction of small muscles at the base of hair follicles that occurs as a reflexive response of the sympathetic nervous system, especially to cold, shock, or fright. Causes hair to stand on end, giving the illusion of a larger, more formidable body size.

The soft or spongy tissue of a plant or fruit, which is usually white or pale in color (e.g., the white part between the skin and fruit of an orange).  

An organ that joins mother and fetus, transferring oxygen and nutrients. The placenta is expelled during birth.

Also known as the thumb, the innermost digit of the forelimb. 

A pattern of mating in which a female animal has more than one male mate.

Having more than one mate.

A mating system in which both males and females have multiple mating partners during a breeding season.

A pattern of mating in which a male animal has more than one female mate.

A mating system in which one male mates and lives with multiple females.

Refers to when a trait occurs in two or more different forms or “morphs” within a species. This accounts for different coloration of animals of the same species, or, in the case of the bald uakari, different forms of color vision. 

Polyspecific troop:
Troops of monkeys belonging to different species.

Born in an advanced state and able to feed itself almost immediately.

Preying of one animal on others.

Able to grasp or hold objects.

Prehensile tail: 
The tail of an animal that has adapted to be able to grasp or hold objects.

Premontane forest
Rainforest that is found along the lower slopes of the mountain at altitudes of 1,640–6,600 ft (500–2,000 m) and where there is a long dry season. 

Primary forest:
Also termed old-growth forest, virgin forest, or primeval forest—a forest that has attained great age without significant disturbance and thereby exhibits unique ecological features and might be classified as a climax community, an ecological community in which populations of plants or animals remain stable and exist in balance with each other and their environment.

Walking with the body approximately horizontal.

The most primitive of the primates. “Prosimian” means pre-monkey. The living (extant) prosimians are in the suborder Prosimii, which includes four families of lemurs, the bushbabies (galagos), lorises and pottos, and the tarsiers.

The generational passing of certain behaviors among non-human primates.


Quadrumanous clambering:

Using both feet and hands to hold onto branches and move in the forest.

A being who walks on all fours.

Using four limbs to move about.

Quadruped digitigrade:
A being who walks on all fours and on the flats of her fingers rather than knuckles.


Rank reversal:

Change in social hierarchy, often by means of agonistic take-over by a previously less-dominant group member.

Remnant population:
A small surviving group of individuals from a once larger population.

​Rhesus factor:
An inherited protein found on the surface of red blood cells. If blood has the protein, it is considered as Rh positive, otherwise it is Rh negative.​

Of, relating to, or situated on the banks of a river.

Riparian forest:
​A forested or wooded area of land adjacent to a body of water.

Related to or situated near a river or riverbank.

​Riverine forest:
A forest that is located nearby or adjacent to a river.



Having a series of sack-like compartments.

Sagittal crest:
A ridge of bone along the middle of the skull. Primates with large jaws have a sagittal crest.  

Savanna forest:
A mixed woodland grassland ecosystem characterized by the trees being widely spaced so that the canopy does not close. Usually found in tropical or subtropical regions with seasonal rainfall.

Scent gland:
Any of various specialized skin glands, occurring in many kinds of animals, that emit an odor commonly functioning as a social or sexual signal, or a defense weapon.

Scrub forest:
A general term for vegetation dominated by shrubs, i.e., low, woody plants, which typically forms an intermediate community between grass or heath and high forest.

Seasonal sexual dimorphism: 
Distinct differences in size or appearance between the sexes of an animal, in addition to differences between the reproductive organs themselves, but only during certain seasons.

Secondary forest:
A forest that has regrown after a major disturbance, such as fire or timber harvest, but has not yet reached the mature state of primary forest.

Secondary logged forest:
A secondary forest that has been logged for timber and resources. 

Secondary vegetation:
Vegetation that has regrown after a major disturbance, such as fire or clearance.

A botanical term referring to plants that lose their foliage for a short period of time; as leaves fall, new ones start growing.

Semi-deciduous monsoon forest:
Trees that shed their leaves during the dry season and grow new leaves at the start of the rainy season.

Living partially, but not wholly, on the ground.

Sexual dichromatism:
When male and female animals of the same species display different colorations.

Sexually dimorphic:
When males and females have different characteristics (size, color, etc.) other than their reproductive organs.

Sexual dimorphism:
Distinct differences in size or appearance between the sexes of an animal in addition to differences in their reproductive organs.

Sexually monomorphic:
Showing no difference between the two sexes other than their genitalia.

Sexual monomorphism:
When males and females of a species strongly resemble one another; other than their genitalia, the sexes cannot be distinguished.

Slash and burn agriculture:
A method of unsustainable farming where farmers clear land by cutting and burning flora in order to create an empty field—a “swidden”—for cultivation. Such practices are detrimental to local ecosystems.

Social monogamy:
A living arrangement between an adult male and an adult female that does not necessarily describe the sexual interactions or reproduction between monogamous pairs; rather it refers to their living conditions. The arrangement consists of but is not limited to, sharing territory, obtaining food resources, and raising offspring.

The formation of new and distinct species in the course of evolution.

A group of living organisms (animals) consisting of similar individuals capable of exchanging genes or interbreeding. The species is the principal natural taxonomic unit, ranking below a genus.

Spiny forests: 
An ecoregion in southwest Madagascar distinctive for its dry, harsh, drought-prone conditions and spiny bush vegetation. It is also known as the “spiny thicket” or “spiny desert.”

Stereoscopic vision:
Combines different inputs of the images received by each eye into a succinct, singular image with the proper size, depth, and proximity.

Relating to the sternum (breastbone).

Strepsirrhine or strepsirhine: 
Relating to the primate suborder Strepsirrhini, consisting of lemurs, lorises, and bush babies, who characteristically have moist areas around their nostrils.

An animal who is not fully adult.

Situated on the higher slopes of mountains just below the timberline.

A taxonomic category that ranks below Genus and above Species.

Submontane forest:
A forest that is situated at the foothills or lower elevation slopes of a mountainous region.

A taxonomic category of one or more families of related organisms that ranks below order and above family.

Subsistence farming:
Small-scale agriculture where farmers grow crops to meet the needs of themselves and their families.

A population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.

A substance, or surface, that is acted upon (as by an enzyme).

Subtropical forest:
A type of forest found in areas outside of the strict equatorial region—but either within or bordering the tropical zone—and having more noticeable seasonal changes. Although temperatures may vary only slightly over a year, rainfall may be distributed unevenly so that wet and dry seasons occur.

Sundaland heath forest:
A type of tropical moist forest, found on the island of Borneo, which typically has a low, uniform canopy approximately 66 feet (20m) high, with thick underbrush and rich growth of moss and epiphytes, and where trees often have closely-spaced trunks.

The region on the body above the pubic bone. 

Swamp forest:
Peat swamp forests are tropical moist forests that grow in permanently water-logged areas with mineral-deficient water; the water-logged soil prevents dead leaves and wood from fully decomposing, over time creating a thick layer of acidic peat. Peat swamp forests are typically surrounded by lowland rainforests on better-drained soils, and by brackish or salt-water mangrove forests near the coast. 

Occurring or living in the same area; overlapping in distribution.   


Tactile hairs

A hair or hairlike structure that is highly sensitive to pressure or touch.

Taxonomic ranking:
In biological classification, the relative level of a group of organisms (a taxon) in a taxonomic hierarchy. Examples of taxonomic ranking are family, genus, species, and subspecies. 

A professional who organizes species into classifications by studying the morphological, behavioral, genetic, and biochemical characteristics of organisms.

A branch of science that encompasses the description, identification, nomenclature, and classification of organisms.

A nest built by a colony of termites underground, above ground (usually as a mound), or in a tree.

Terra firme forest:
Means “firm earth” and refers to a forest that is not overrun by flooded rivers. This forest is taller and more diverse than flooded forests. 

Living on the ground.

A process that allows your body to maintain its core internal temperature. 

Toilet claw:
A specialized grooming claw common to prosimians and certain other primates.

A dental structure in the lower front jaw of some animals that are grouped as if to form a comb that is used by these animals to groom and clean their fur or hair.

A sleep-like state in which the body decreases physiological activity. 

The practice of intentionally moving plants and animals from one area and releasing them in another to improve their survival chances and combat biodiversity loss—is usually considered as a last resort to save a species.

Tri-chromatic vision:
The ability to see in color thanks to three color receptors (rods and cones) at the back of the eye in the retina. Humans and most Old World monkeys have trichromatic vision—i.e., they distinguish blues, greens, and reds.

Tropical forest:
A type of forest found in areas with high regular rainfall and no more than two months of low rainfall, and consisting of a completely closed canopy of trees that prevents penetration of sunlight to the ground and discourages ground-cover growth. 


Umbrella species:
A species whose conservation indirectly protects the many species in an ecosystem.
Understory layer (of the rainforest):
The third layer of the forest, above the forest floor. Little sunshine reaches this area, so plants must grow larger leaves to reach the sunlight. These plants seldom grow to 12 feet.

United Nations Educational, Scientific and Cultural Organization:
a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences, and culture).


Várzea forests:

A seasonal floodplain forest inundated by whitewater rivers that occurs in the Amazon biome.

The stomach or belly area, the outside lower surface of the torso.

Wild animals that are believed to be harmful to crops, farm animals, or game, or that carry disease.

Animals with a backbone, including mammals, birds, reptiles, amphibians, and fish.

A part of the body that in the course of evolution, has degenerated and become functionless; the last small part that remains of something that once existed.

A group of 35 species including the genets, binturong, civets, and linsangs.

Vomeronasal organ (VNO):
Also called Jacobson’s organ, it is the paired auxiliary olfactory (smell) sense organ located in the soft tissue of the nasal septum, in the nasal cavity just above the roof of the mouth (the hard palate).


World Heritage Site:
A landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific, and Cultural Organization. (UNESCO). World Heritage Sites are designated by UNESCO for having cultural, historical, scientific or other form of significance.  


An infectious disease caused by a pathogen (an infectious agent, such as a bacterium, virus, parasite, or prion) that has jumped from a non-human animal to a human.