abdomen: the back (last) segment of an insect’s body.
abundance: a large amount of something.
acorn: the nut of an oak tree.
adapt: to develop characteristics or behaviors that make it easier to survive in a particular habitat.
adaptable: able to change behavior to suit new conditions.
adaptation: a characteristic or behavior that makes it easier to survive in a particular habitat.
adapted: having characteristics that help a plant or animal survive in its environment.
adhesive: something that makes things stick together.
adobe: building material made of sun-dried earth and straw
advantage: something that is useful or helpful in a particular situation.
advocate (n.): someone who supports an idea, plan, or action.
aerie: the nest of a bird, such as an eagle, built high in a tree or on a cliff or building.
aggressive: behaving fiercely or in a threatening way.
algae (pl. of alga): certain kinds of plants that do not have roots or stems and usually grow in water.
amphibian: one of a class of cold-blooded animals—including frogs, toads, and salamanders—that live in water and breathe with gills when young, then develop lungs and live on land as adults.
amphipod: one of a group of small sea creatures with hard body coverings, related to shrimps, crabs, and lobsters.
ancestor: a member of a family who lived a long time ago.
antennae (pl. of antenna): the long “feelers” on the head of an insect or other animal.
aphid: a tiny insect that feeds on the juices of plants.
aquifer: an underground space filled with fresh water.
architect: a person who designs buildings.
Arctic: the frozen area around the North Pole.
arid: dry; receiving little or no rain.
aridland: a dry area that receives only a small amount of rain or snow.
artificial: not natural or real; created by people.
atmosphere: the mixture of gases that surrounds Earth.
audit: the process of systematically examining or reviewing something.
bacteria: microscopic organisms that live in soil, water, organic matter, or the bodies of plants and animals.
baleen: bony plates in the mouths of certain whale species used to filter food out of water.
ban (v): to forbid; to make something against the law.
barb: a sharp, pointed part of something.
barnacle: a small shellfish that attaches itself to hard surfaces, such as rocks and boats.
barrier: something that blocks movement from one place to another.
beach hopper: a small creature with a tough shell that live on beaches, usually in washed-up seaweed, and hop like fleas; also called sand hopper, sand flea, beach flea.
beak: the hard, horny part of a bird’s mouth; also called bill.
beetle: a type of insect with wings that form a hard cover on its back when it is not flying.
beneficial: helpful; having a good effect on a place or situation.
bill: the hard, horny part of a bird’s mouth; also called beak.
biodiversity: a condition in nature in which many different species live in an area.
biologist:a scientist who studies living things.
biology: the science that deals with the study of living things.
biomass: all living material in a habitat.
biome: a very large area characterized by a common type of ecological community, such as a grassland or forest.
biomimicry: copying designs and processes from nature.
bird of prey: a bird that hunts and eats other animals
bird steward: a person who protects birds in their natural environment.
blizzard: a very heavy snowstorm with very strong winds.
breed: to mate and produce offspring.
breeding ground: the area where migratory birds and other animals go to breed and raise their young.
breeding range: the entire area in which migratory birds and other animals breed and raise their young; breeding ground.
brood chamber: the space built by female bees in which to lay their eggs. Also called a “bee pot.”
burrow: a tunnel or hole in the ground made by an animal.
cache (v): to collect things and put them away for use in the future.
calcium: a chemical element that is found in teeth and bones.
camouflage: coloring and patterns that make an animal or object blend in with its surroundings.
canopy: the highest part of a forest where the tallest trees form a sheltering cover.
carbon dioxide: a gas that is a mixture of carbon and oxygen. People and animals breathe carbon dioxide out; trees and other plants absorb it.
carbon footprint: the negative impact something or someone has on the environment, based on the amount of carbon emitted from normal activities.
caribou: a large animal of the deer family found in cold northern regions.
carnivore: an animal that eats meat.
caterpillar: the wormlike stage in the life cycle of a butterfly or other insect; pupa.
cattail: a tall, thin marsh plant with narrow leaves and brown, fuzzy pods at the top.
cavity: a hole or hollow space in something solid, such as a tooth or a tree.
cavity-nester: a bird that lays its eggs in a hole in a tree or a nestbox.
cells: the microscopic units that are the basic building blocks of living things.
characteristic: a quality or feature.
chrysalis: the stage in the life cycle of a butterfly between caterpillar and adult; also called pupa.
clearcutting: cutting down all the trees in an area.
climate: the general weather in an area over many years.
climate change: a shift in Earth’s weather patterns relative to long-term average conditions; effects include rising temperatures and changing weather patterns such as increased frequency of intense rainfall events or declining snowfall. See global warming.
coal: a shiny black mineral formed from the remains of ancient plants; burned as a source of energy; a fossil fuel.
coast: the land next to an ocean or sea.
coastal marsh: a low, wet area near the ocean.
colonize: to move into a new area and stay there.
colony: a large group of animals living together.
community scientist: a person not trained as a scientist but who helps collect scientific information or takes part in activities that help scientists; sometimes called “citizen scientist.”
compact fluorescent bulb (CFL): a type of light bulb that lasts longer and uses less energy than a “regular” light bulb.
compass: an instrument for determining directions.
compete: to try to get something that others are also trying to get.
compost: a mixture of decayed organic matter that adds nutrients to soil.
compound: having two or more parts.
confluence: the place where two or more rivers or streams meet and flow together.
conservation: the process of protecting and maintaining natural places.
conserve: to protect from loss or overuse.
contraption: a strange or unusual machine or piece of equipment.
cooperative breeder: a type of animal in which other animals of the same species help each other raise their young.
course: the route for getting from one place to another.
crepuscular: active mainly at twilight.
crest: a tuft of feathers that stands up on top of a bird’s head.
crop: a plant, such as corn or apples, that is grown in large quantities to be used for food.
crustacean: a sea creature that has an outer skeleton, such as a crab, lobster, or shrimp.
cycle: a series of things that is repeated regularly, like the seasons of the year.
dam: something built across a river or stream to hold back flowing water.
data: information; facts.
DDT: a pesticide used to kill insects that damage crops, which had harmful effects on birds and other animals and was banned in the U.S. in 1973.
decal: a picture, design, or label that will stick to a surface.
decay: to rot.
decline: to go down or decrease.
decomposers: organisms that cause decay or break down the bodies of dead plants and animals into components that can be reused in the ecosystem.
deciduous: the word for trees that lose all of their leaves in one season.
decompose: to rot or break down.
decoy: a carved model of a bird used to attract other birds.
defend: to protect from harm.
deformed: changed from natural appearance by negative influences such as pollution or stress; misshapen.
delta: land formed by mud and sand deposited by a river where the river meets the sea.
depression: a hollowed-out place.
descendant: child or offspring.
desert: a habitat where there is very little rain and few plants grow.
destination: the place a person, animal, or vehicle is traveling to.
detect:to notice or find something.
development:changing a natural place so it can be used by humans for homes, roads, etc.
digestive system: the organs in an animal’s body that break down food so that it can be used for energy and growth.
disadvantage: something that causes a problem or makes a situation more difficult.
distraction: activity that takes attention away from something.
diurnal: active during the day.
diversity: the condition of having many different kinds of things, such as people, plants, and animals.
documentary: a movie that shows real people in real situations.
dominate: to be the most common thing, such as a plant, in an area.
dormant: in an inactive state for a period of time.
drone: a male bee who mates with the queen bee.
drought: a long period during which there is little or no rain or snow.
dune: a hill of sand formed by wind near an ocean or large lake.
ecologist: a scientist who studies the relationship between plants, animals, and their environment.
ecology: science that deals with living things and their environments.
ecosystem: a community of plants and animals interacting with each other and their environment.
eider: a large duck found in northern coastal regions.
electrical current: the flow of electricity through wires.
embryo: the early stage in the growth of a human or animal.
emerge: to come out of something.
endangered: at risk for becoming extinct.
Endangered Species Act: a United States law passed in 1973 that provided ways to protect animals and plants whose populations are in danger of being severely reduced or eliminated, and also to protect the habitats where those animals and plants live.
Endangered Species List: a list put together by the U.S. government of animals and plants that need to be protected because they are at risk of becoming extinct without protection.
endemic: living in a particular place or region.
energy: the ability of something to do work; the power (for example, from coal or electricity) that makes machines work.
environment: the natural world—land, sea, and air; all the things that influence the lives of living things.
equivalent: the same as something else in amount, value, or importance.
erosion: the process of washing or wearing away, such as the effect of wind and rain on soil.
estuary: where a river meets the sea, mixing fresh water and salt water.
evergreen: the word for trees whose leaves stay green throughout the year.
evolve: to change gradually over time in response to the environment.
exhale: to breathe out.
experience: knowledge or skill gained from doing something.
exterminate: to kill off a population of living things.
extinct: no longer living.
extinction: the condition in which an animal or plant has died out completely, so that there are no living examples.
fatal: causing death.
fertilization: the process of combining pollen from one flower with cells of another flower, allowing the flower to make seeds.
field guide: a book that is used to identify plants, animals, minerals, and other things in their natural environment.
field mark: a characteristic that helps identify a bird, such as color, color pattern, size, tail shape, leg length, size and shape of beak, kind of feet, and so on.
fin: a part of a fish’s body that it uses for swimming and steering.
flock: a group of animals, such as birds or sheep.
floodlight: a light that shines over a wide area.
floodplain: the low flatlands along a river.
flyway: the route birds follow as they migrate.
food chain: the relationships among a group of living things based on the flow of energy from food.
forage (v.): to search for food.
forb: a plant that grows among grasses.
fossil: the remains or imprint of an organism that lived in the distant past, usually preserved in Earth’s crust.
fossil fuel: fuel, such as oil, coal, and natural gas, made from the remains, found deep inside Earth, of plants and animals that lived in the distant past.
fragment: a piece that is broken off from something bigger.
fragmentation: the process of breaking something into smaller pieces.
fresh water: the part of the Earth’s water supply that is not salty, such as the water in rivers, streams, lakes, and ponds.
fungi: plural of fungus, a type of plant, such as a mushroom, that has no leaves, flowers, or roots.
generator: a machine that turns mechanical energy (such as the turning of a turbine) into electrical energy.
generation: group of individuals living within the same time frame.
geothermal energy: energy produced by tapping the heat that occurs naturally deep inside Earth.
geyser: a natural opening in the ground through which hot water or steam shoots out with force.
gizzard: part of a bird’s digestive system that grinds down food.
glacier: a large body of ice that moves slowly over land.
global climate change: the long-term change in weather patterns all over the world.
global warming: a type of climate change by which temperatures on Earth are rising slowly as a result of the build-up of carbon dioxide and other gases in the atmosphere, which in turn is caused by the burning of fossil fuels.
gopher tortoise: a large, land-living turtle that is native to the southeastern U.S.
GPS: Global Positioning System; a system for using satellite signals to determine the location of something on Earth’s surface.
grant (n.): money given for a particular purpose.
grass: a group of plants with long, thin, erect leaves.
grassland: a large, open, usually flat area covered with grasses and having few trees.
gravity: the force that pushes down on Earth and keeps things from floating up into the air.
“green”: a term used to describe products and actions that do not harm the environment.
greenhouse: a building designed to control light and heat in order to grow and protect plants.
greenhouse gas: a gas, such as carbon dioxide, water vapor, nitrous oxide, and methane, that traps heat in Earth’s atmosphere.
groundwater: water that is underground in the soil or in spaces in and between rocks.
habitat: a place in which an organism is normally able to find the resources it needs for survival.
hatchling: an animal recently hatched from an egg.
hazard: something that is dangerous.
headwaters: the place where a river begins.
hemisphere: one half of the Earth or other sphere.
herbaceous layer: the layer above the forest floor, where ferns, grasses, and other plants grow.
herbicide: a chemical used to kill unwanted plants.
herbivore: an animal that eats plants and plant material.
hibernate: to spend the cold months in an inactive or dormant state.
hive: a structure, built by bees or by beekeepers, in which large numbers of bees live and make honey.
host plant: a plant that provides necessary food and other resources for certain insects or other organisms.
hot spring: a natural body of water that is heated deep inside Earth.
hover: to remain in one place in the air.
hurricane: a large swirling storm that starts over warm ocean water and has very heavy rain and very strong winds that can cause damage and flooding when the storm crosses onto land.
hyperphagia: in animals, eating large amounts of food in order to prepare for a time of going without food.
icecap: an area that is always covered by ice and snow.
ice floe: a sheet or mass of floating ice.
immigrant: a person who leaves one country to live permanently in another country.
Important Bird Area (IBA): a program sponsored by organizations around the world to identify and conserve areas that are vital to birds and other organisms.
inhale: to breathe in.
inland: away from an ocean or sea.
insect: a class of animals that have six legs, three main body parts, two antennae, wings, a hard outer covering, and no backbone.
instinct: the natural behavior of an animal in response to environmental factors or other influences.
insulation: something that protects against heat or cold.
interdependent: depending on or needing each other.
invasive: regarding plants, coming from the outside and tending to spread and crowd out native plants.
invasive species: nonnative plants or animals that tend to spread or multiply in a way that crowds out or kills native species.
invertebrate: an animal that does not have a backbone, such as an insect, a crustacean, or a worm.
keystone species: an animal species that, when it and its habitat are protected, has the effect of protecting other organisms that share its habitat.
krill: small shrimp-like creatures that are a major source of food for some whales.
landfill: an area where garbage is collected and covered by a layer of earth.
landmark: an easily seen object that can be used to identify a particular place or route.
landscape: a large outdoor area with plantings and natural features.
lagoon: a shallow area of water that is separated from the sea by a narrow piece of land.
larva (s. of larvae): the wormlike stage in the metamorphosis of a moth or other insect that hatches from the adult’s eggs; caterpillar.
leaf litter: the layer of fallen leaves, twigs, and other natural organic matter that covers the floor of a forest.
life cycle: the series of changes that a living thing goes through from birth to death.
limpet: a kind of mollusk that clings tightly to rocks and other hard surfaces.
locomotion: the act of moving from one place to another.
locust: a type of migratory grasshopper.
magnetic field: the area around a magnet that attracts metals.
magnetism: the effect that occurs in a magnetic field when metals are attracted to one another.
mammal: one of a class of animals that are warm-blooded and have a backbone and hair.
mangrove: a tropical tree or shrub that grows in coastal water or wetlands with many roots that trap soil and eventually form land.
manta ray: a kind of fish that has broad fins that look like wings.
marathon (adj.): long-distance.
marine: living in or related to the sea.
mariner: a person or animal that that spends a lot of time at sea.
marsh: an area where the land is low and wet.
mate (v.): to breed in order to make offspring.
mature:fully developed; full-grown.
methane: a colorless, odorless gas that burns easily; one of the greenhouse gases.
microhabitat: a very small environment in which an organism lives its life.
microscopic: a word for something that is so small that it can only be seen with a microscope.
migrant: an animal or person that migrates.
migrate: to relocate from one habitat to another in a regular cycle.
migration: the process of relocating from one habitat to another in a regular cycle.
migratory: adjective to describe a bird or other animal that migrates.
mimic: one who imitates another.
milkweed: a type of plant; the host plant for monarch butterflies.
mollusk: an animal, such as a snail or clam, with a soft body usually enclosed in a hard shell.
monitor: to keep track of.
motion sensor:an electronic device that detects movement, often including a light that goes on which movement is detected.
mouth: where a river ends at the ocean or sea.
mudflat: an area of land just below the surface of water or that is sometimes covered and sometimes not covered as the water level rises and falls.
muskox: a large shaggy-coated wild ox found in Alaska, Canada, and Greenland.
mussel: a kind of mollusk with a two-part shell.
nape: the back of the neck.
native: originally from a particular place, rather than coming from or being brought from somewhere else.
natural gas: a gas that formed naturally deep below Earth’s surface, and used as a source of energy; a fossil fuel.
natural resource: something that occurs in nature and can be used for a beneficial or helpful purpose.
navigate: to find the way from one place to another.
natural resource: something—such was water, trees, minerals—that is part of nature and that is useful to people.
naturalist: a person who is interested in, observes, and values nature.
navigation: the process of finding the way from one place to another.
nectar: a sweet liquid made by some flowers.
neotropical migrant: a bird that breeds in North America during the spring and summer and then migrates to Mexico, Central America, South America, or the Caribbean islands for the winter.
nesting grounds: the region where migratory birds go to breed and raise their young; also called breeding grounds.
nestling: a bird that is too young to leave its nest.
nocturnal: active at night.
nonnative: not naturally from a particular place.
nonrenewable: not able to be replaced.
nourishment: food that keeps a plant or animal healthy and able to grow.
nurture: to take care of and encourage growth.
nutrient: something such as a vitamin or mineral needed by living things to grow and stay healthy.
nutritious: describing food that helps a body grow and stay healthy and strong.
ocelli (pl. of ocellus): simple (rather than compound) eyes.
offspring: babies; young.
oil: a thick, greasy substance formed deep below Earth’s surface from decomposing ancient plants; used as a source of energy—for example, heating oil, gasoline; a fossil fuel.
old-growth forest: a forest that has not been changed by people.
omnivore: an animal that eats many different kinds of foods, rather than just plants (herbivore) or just other animals (carnivore).
orca: a species of whale that is black-and-white and kills animals such as seals for food; also called a killer whale.
organic: grown or raised without the use of pesticides and other chemicals.
organism: a living plant or animal.
orient (v.): to figure out where one is in relation to one’s surroundings.
orientation: the process of figuring out where one is in relation to other things.
overfishing: catching so many fish that the population of fish may not recover.
overwinter: to spend the winter.
owl pellet: the parts of an animal that an owl has eaten that are undigestible and that the owl coughs up as a bundle of fur and bones.
owlet: a young owl.
oxygen: a gas found in air that is necessary for people and animals to breathe.
oyamel fir tree: a type of evergreen tree native to the mountains of Mexico.
Pampas: an area of grassland in parts of Argentina, Uruguay, and Brazil.
parasitic: word for an animal or plant that lives or grows on another animal or plant and harms it.
parasite: an animal or plant that lives or grows on another animal or plant and harms it.
perceive: to become aware of something through one’s senses.
perennial: term for plants that live through all seasons of the year.
permafrost: a layer of soil that is always frozen in cold regions of the world.
pest: an insect or other organism that interferes with human activity, such as damaging crops.
pesticide: a chemical used to kill organisms that are considered pests, such as some insects.
photosynthesis: the process in which plants use the Sun’s energy to turn water and carbon dioxide into sugars they need to grow.
plover: a bird with pointed wings and a short bill that searches for food along the shore.
pod: a group of whales that generally stays together.
polar: having to do with the areas around Earth’s North Pole and South Pole.
pollen: the powdery material produced by plants that is transferred from flower to flower, making it possible for plants to reproduce.
pollinate: to carry pollen from one flower to another, making it possible for plants to reproduce.
pollination: the process of transferring pollen from one flower to another, making fertilization and reproduction possible.
pollinator: an organism, such as an insect or a bird, that transfers pollen from one plant to another.
pollutant: a harmful substance that gets into air, water, and soil because of human activities.
pollute: to add a harmful substance to something, such as air or water.
pollution: harmful substances (solid, liquid, gas) that get into air, water, and soil because of human activities.
populate: to fill in with people, animals, plants, or other things.
population: a group of one type of living things in a particular area.
pore: a tiny hole or opening in the surface of something, such as skin or a leaf.
prairie: grassland; a large, mostly flat area covered with grasses and having few trees.
precipitation: water that has evaporated and then falls from the sky in the form of rain, hail, sleet, or snow.
predator: an animal that hunts other animals for food.
preserve: to protect something so that it stays in its original state.
prey: an animal that is hunted by another animal for food.
probe (v.): to explore or examine something using a tool or a body part, such as a bird’s beak.
propel: to push something forward.
protein: a substance found in foods that the bodies of people and animals need to grow.
pulp: a soft, spongy material made from a mixture of liquid and something else such as paper.
pupa (s. of pupae): the stage in a butterfly’s life cycle during which it changes from a caterpillar to an adult; also called chrysalis.
radiate: to spread outward.
rain garden: a garden containing native plants, designed to catch or slow down rainwater runoff, helping to filter out pollutants before they reach rivers and other bodies of water.
range: the area over which a bird or other animal normally lives its life.
ranger: a person in charge of a park, forest, or other natural area.
raptor: a type of bird, such as an eagle or a hawk, that has a strong beak and sharp talons for catching live prey.
recycle: to reuse.
refine: to change oil and other natural resources into a form that is usable for energy production.
reflection: an image that is seen in a mirror or on a shiny surface.
reflective: a surface, such as glass, that causes light, sound, or heat to move away instead of going through.
reflex: an automatic action that happens without the control of a person or animal.
refuge: a safe place.
reliable: able to provide what is needed.
renewable: able to be replaced.
renewable energy sources: solar, wind, and geothermal energy are called “renewable” energy sources because they can always be replaced, which means we will never run out of them.
reproduction: the process in which plants and animals make more of their kind.
reptile: a class of cold-blooded animals—including snakes, turtles, lizards, and alligators—that have no legs or short legs and a body covered in scales or bony plates.
reserve (n.): something set aside for the future.
restore: to bring back or return to an original condition.
riparian: a term for the area alongside a river.
rodent: a small mammal such as a mouse, rat, squirrel, or vole, that has sharp front teeth.
rookery: a place where bird’s gather to nest and raise their young.
roost (v., n.): for birds, to settle down to rest or sleep; a place where birds settle down to rest or sleep.
runoff: material carried by rainwater into rivers, lakes, and the ocean.
sagebrush: a shrub that grows in dry areas of the western United States (U.S. for consistency).
salt water: the part of Earth’s water supply that is naturally salty, such as the water in oceans.
saltwater bay: an area of an ocean or sea that is partially surrounded by land.
sanctuary: a natural place where birds and other animals are protected.
scrape: a bird’s nest that is a hollowed-out place in the sand.
scrubland: a type of habitat in Florida where stubby oak trees and bushes grow in dry white sand.
sea anemone: a kind of sea creature that looks like a flower and has stinging tentacles.
seabird: a bird that spends much of its life in or near the sea.
seastar: a sea creature with five or more arms; also called starfish.
secchi disk: a black and white disk that is lowered into a body of water to determine how clear or clean the water is.
sensor: a tool or instrument used to sense, or “feel,” something.
sensory: relating to information received from the physical senses: taste, touch, sight, hearing, or smell.
sentinel: a lookout.
sewage: liquid and solid waste from homes and businesses that is carried away in sewers and drains.
shore: the area next to a body of water, such as a sea or lake.
shorebird: a bird that lives in open areas of beaches, grasslands, wetlands, and tundra; examples of shorebirds include oystercatchers, plovers, and sandpipers.
shrub: a low-growing plant with woody stems.
silt: very small particles of rock carried by a river that can settle and build up on the bottom of the river.
skink: a kind of lizard.
sod: the top layer of soil and the grass attached to it.
solar: relating to the sun.
solar cell: a device used to turn the Sun’s heat and light into a power source.
solar energy: energy that uses sun’s rays for heating and to create electricity .
solar panel: a group of solar cells combined to collect the Sun’s energy to produce power.
solar power: power whose source is the Sun’s heat and light.
solitary: living alone rather than in a group.
songbird: a bird that is able to produce a complex series of sounds called a song, used to communicate with other birds.
sprout (v.): to produce new leaves, buds, etc.
species: a group of plants or animals that share certain characteristics and are able to breed and reproduce their own kind.
squid: a sea animal with long tentacles and a long soft body.
stalk: to hunt or track something while trying not to be noticed.
stopover: a place where migratory animals spend time during their migration.
structure: something that is built.
submerge: to put under water.
sugar: a substance that can be used by living things as a source of food energy.
survive: to continue to live.
sustainable: able to be done without harming the environment or using up resources.
swamp: an area covered with water where trees and other woody plants grow.
swarm: a large group of flying insects.
talon: the sharp claw of a bird of prey
taproot: the main root of a plant that grows vertically down into the soil.
theory: an explanation of something based on analysis of available facts and observations.
thermals: currents or waves of warm air that rise up from the ground.
thorax: the middle section of the body of an insect.
threat: something that could cause injury, damage, or death.
threatened: is at risk for becoming endangered.
thrive: to live and grow well.
tidepool: a pool of water at the shore left behind when the tide goes out.
tissue: a mass of similar kinds of cells that form the organs and other parts of living things.
tornado: a whirling column of air that spins very fast and looks like a dark funnel reaching from the sky to the ground; A tornado usually travels across the ground and destroys most things in its path.
torpedo: an underwater weapon with a long, rounded shape and a pointed front end.
torpor: a sleeplike state.
toxic: containing poisonous material that can cause illness or death.
transmitter: a device used to send out radio or television signals.
transparent: able to be seen through.
trill: a high-pitched sound that is repeated rapidly.
tropical: related to an area where the climate is warm or hot most of the year.
tropical forest: a forest that grows in an area of Earth where the climate is warm or hot most of the year.
tropics: the area of Earth where the climate is warm or hot most of the year.
tuft: a small bunch of feathers, hairs, grass, etc.
tundra: a level or rolling treeless area in a cold region, usually covered by permafrost; tundra plants include mosses, lichens, and small shrubs.
turbine: a kind of engine that is powered by the turning of blades or a wheel by wind, water, or steam.
ultraviolet: term for a type of light that cannot be seen by the human eye.
umbrella species (also, indicator species): a plant or animal that, when it is doing well in an environment or habitat, indicates that the environment or habitat itself is healthy.
understory: in a forest, the space between the floor and the canopy where small trees and bushes grow.
United Nations: an organization of most of the countries in the world for the purpose of working together for peace and cooperating on other projects that help countries and their people.
unspoiled: in a natural, healthy state.
urban: in a city; relating to the characteristics of a city.
vegetarian: an animal that eats only plant matter.
vertebrate: an animal that has a backbone.
water treatment plant: a place that receives water from homes and businesses and treats it with chemicals and other processes to clean it before releasing it to a lake, river, or other body of water.
waterbird: a bird that swims or wades in water.
waterfowl: swimming birds, such as ducks and geese.
watershed: the entire area from which water drains into a particular river, lake, or other body of water.
weather: the current conditions of the atmosphere at a particular time.
weed: a plant that grows where it is not wanted.
wetland: an area, such as a swamp, marsh, or lake, that is sometimes or always covered with water or where the soil is always saturated.
whetstone: a stone used for sharpening knives.
wildfire: a large fire that spreads quickly through dry wooded and brush-covered areas.
wildlife: wild animals living in nature.
wind energy: energy that is created using wind turbines; see wind turbine.
wind turbine: a tall structure with large blades that are turned by the wind in order to power an engine that creates electricity.
wintering grounds: the area where an animal that migrates spends the part of the year when it is not breeding and raising young.