Not derived from living organisms.

A biological characteristic that improves the chance of survival of an organism and its descendants.

adaptive radiation
When a taxon evolves into a number of different forms.


The study of human origins, behavior, and physical, social, and cultural development.

Living in trees.

Any object that was made, used, and/or transported by humans that reveals information about humans in the past.

The variety and interdependence of all living things. Biodiversity includes all living organisms, the genetic differences among them, the communities, cultures, habitats and ecosystems in which they evolve and coexist, and the ecological and evolutionary processes that support them.

Of or relating to living things.

In a forest, the zone above the ground in the bulk of the tree branches.

carbon dating
A method of determining the approximate age in years of a carbon-bearing object by measuring the decay of radioactive carbon-14. Also called radiocarbon dating.

Average weather conditions of a region, including temperature, precipitation, and winds.

The management and protection of the natural world.

The geologic period that lasted from 146 million years ago to 65,500 years ago. It followed the Jurassic period and preceded the Tertiary period.

critically endangered
Very likely to become extinct in the foreseeable future. "Critically endangered" species on the IUCN Red List are considered "at extremely high risk of extinction."

Removal of forests, usually rapidly and over large areas.

density (population)
The number of organisms in a population in a given area.

The geographic occurrence or range of an organism.

Active during the day.

A complex molecule found in every cell that contains an organism's genetic code. Every organism has variations in the code contained in its DNA.

The development of an interdependent relationship between humans and another species.

Animal excrement.

The location of objects by reflected sound waves.

The study of the interactions of living things with each other and their physical environment.

A relatively large area of land or water that contains a geographically distinct assemblage of natural communities.

A community of interacting organisms and their physical environment.

elephant bird
An extinct family of flightless birds native to Madagascar. They are considered the largest birds that ever lived.

Likely to become extinct in the foreseeable future. "Endangered" animals on the IUCN Red List are considered "at very high risk of extinction."

All the external factors that affect an organism during its lifetime.

An explanation for the gradual development of life over time via natural selection. Paraphrased as "descent with modification."

The death of all members of a taxon. Animals on the IUCN Red List are considered "extinct" when there is "no reasonable doubt that the last individual has died."

The loss or removal of a species from one or more specific areas or all areas.

A group of related genera.


Any remnant or trace of an organism of a past geologic or prehistoric age, such as a skeleton or the imprint of a leaf, embedded and preserved in the Earth's crust.

fragmentation, habitat
When contiguous areas of habitat are divided into smaller pieces by development, agriculture, or roads.

gallery forest
A forest along the margins of a river or stream.

An organism that can survive under a wide variety of conditions. It does not specialize to live under any particular set of circumstances.

Gondwanaland (Gondwana)
A supercontinent that existed from from the Cambrian to the Jurassic period, mainly composed of South America, Africa, Madagascar, India, Antarctica, and Australia.

The environment where an organism can and does live.

The bone of the upper arm or fore limb.

The intentional or unintentional escape or placement of a species into an ecosystem as a result of human activity.

kilometer (km)
A unit of length equal to 1,000 meters, or 0.62 miles.

larva (pl. larvae)
The earliest free-living (e.g., hatched) life stage of an organism that undergoes metamorphosis.

Imaginary horizontal lines that allow the measurement of a position north or south of the equator. Latitude is measured in degrees (at the equator, one degree = 60 nautical miles, or 111 kilometers). The equator is at a latitude of 0∞ and the poles lie at latitudes of 90∞ north (North Pole) and 90∞ south (South Pole). Because of Earth's oblateness, a degree of latitude near the polar regions is about 112 km in length.

least concern
Least concern species on the IUCN Red List are not endangered or threatened.

A group of diverse primates that are native to Madagascar.

Relating to the sea.

The largest-size category of animals in a community.

A unit of length in the metric system equal to 3.28 feet.

The form and structure of anything, usually applied to the shapes, parts, and arrangement of features in living and fossil organisms.

native species
A species that historically occurred or currently occurs in an ecosystem other than as a result of an introduction.

natural history
The study of the natural world.

natural selection
A mechanism by which populations adapt and therefore evolve. Those individuals who are best suited to an environment survive and reproduce most successfully, producing more similarly well-adapted descendants.

The place that a species occupies in the biotic and abiotic environment. It is often defined in terms of the minimal conditions under which an organism can survive.

Active only at night.

nonnative species
A species that has not historically occurred in an ecosystem, but does occur as a result of its introduction to that ecosystem. Also called alien species, exotic species, or introduced species.

The taxonomic category of organisms that rank below (are more related than) a class but above (less related than) a family.

The study of fossils.

The geologic epoch lasting from 1,800,000 years ago to 10,000 years ago. It follows the Pliocene epoch and precedes the Holocene epoch.

A group of organisms of one species, occupying a defined area and usually isolated from similar groups of the same species.

A animal of the order Primates. Primates include lemurs, monkeys, apes, and humans.

radio tracking
Measuring the movement of an organism via the transmission of radio waves from a transmitter on the animal to a receiving station for recording and analysis. Also called radio telemetry.

The area naturally occupied by an individual, population, or species.

An area of land set aside for the use or protection of a species and its habitat. Also called a protected area or conservation area.

Unconsolidated particles, ranging from clay-size to boulders, produced by the breakdown of rocks that may be carried by natural agents (wind, water, and ice) and eventually deposited to form sedimentary deposits. Organisms and chemical precipitation can also produce sediment.

A lemur of the genus Propithecus. They are diurnal, arboreal, medium-sized lemurs (4ñ6 kg) with long silky fur.

An organism which has adopted a lifestyle specific to a particular set of environmental conditions.

A group of individuals, usually identifiable by a set of distinctive features, with a unique evolutionary history. Classically, the members of a species can interbreed only with each other to produce fertile offspring.

spiny desert
A sparsely forested dry habitat in the southern regions of Madagascar dominated by cactuslike Didieraceae, one the island's endemic plant families.

structurally defended
Having structures meant to stymie predation, such as the hard shell of a nut or the spines of a cactus.

A fossil not buried long enough to turn partially or completely into minerals.

As used in ecological science, to conduct a rigorous study of certain aspects of nature, such as the kind, abundance, or distribution of various organisms residing in some defined study area.

taxon (plural: taxa)
Any organism or group of organisms of the same taxonomic rank; for example, members of a kingdom, phylum, class, order, family, genus, or species.

Populations or species likely to become endangered in the near future.

A group of primates of the same species.

At risk of extinction as a species, but not at a level that warrants its identification as endangered. "Vulnerable" species on the IUCN Red List are considered "at high risk of extinction."