Browse "Nature & Geography"

Walnut (Juglans), genus of trees of the walnut family (Juglandaceae). The roughly 15 known species are widely dispersed through temperate and tropical regions.

The walrus is a tusked, fin-footed mammal. In Canada, the Atlantic walrus is found primarily along the northern coasts of Hudson Bay, Davis Strait, Foxe Basin and Baffin Bay.

The Wapiti (Cervus canadensis) is the second largest (after the moose), most highly evolved Old World deer. It is also known as the American elk.

Warbler is a name applied to several groups of birds, primarily the New World wood warblers, and Old World warblers of which only 3 species commonly breed in Canada.

Wasp is a term applied to stinging insects in the division Aculeata of the order Hymenoptera, which also includes ants and bees.

Worldwide, over two-thirds of precipitation falling on land surfaces is evaporated and transpired back into the atmosphere. In Canada less than 40% is evaporated and transpired; the remainder, called the water yield, enters into streamflow.

Water Flea, tiny crustacean that swims with jerky movements.

A large family of freshwater plants known as the water lily (Nymphaeaceae) is characterized by large, shield-shaped leaves and showy blossoms. They are mostly tropical or subtropical. Four genera and 9 species are native to Canada, of which 3 species are important.

Water pollution occurs when discharges of energy or materials degrade the quality of water for other users, including both humans and wildlife. Pollution can affect inland waters such as lakes, rivers and groundwater, as well as coastal marine waters.

A waterfall is a phenomenon which occurs when water flowing in a river channel encounters a vertical or near-vertical drop in the channel bed.

Waterfowl is a general term used for members of the family Anatidae, composed of closely allied species commonly known as ducks, geese and swans.

Waxwing is a family of birds comprising 8 species, including the true waxwings, the palmchat of Hispaniola and the silky-flycatchers of the southwestern US and Central America.

The weasel is a small, long-bodied, carnivorous mammal of the family Mustelidae. Three species of weasels are found in Canada: the short-tailed weasel, also known as the ermine or stoat (Mustela erminea), the long-tailed weasel (Mustela frenata), and the least weasel (Mustela nivalis). The least weasel is the smallest species in the order carnivora. The genus Mustela also includes mink, black-footed ferret, and the introduced European ferret.

WEATHER FORECASTING is the attempt to understand atmospheric patterns to predict the weather conditions that will occur at a specific place and time, including temperature, wind, cloud, precipitation and humidity.

Most modern meteorologists attempt to cope with physical processes by expressing them mathematically, ie, by creating mathematical models of the atmosphere. Powerful computers are then used to solve problems.

Weather modification has been used in an attempt to increase rainfall and snowfall, to suppress hail, to clear fogs, to modify tropical cyclones and to suppress lightning. The term "weather modification" is not normally used to describe inadvertent changes in our WEATHER.

   Weather in Canada ranges from the extreme cold of the Arctic to tornadoes and other severe weather in the southern regions; from the storms and fog of the Atlantic to the dry heat and majestic thunderstorms of the prairies.

Fragmented rock materials formed by mechanical weathering are normally larger than clay particles. These materials constitute major sources of sediment for later erosion, transportation and deposition under the impetus of gravity, wind, water or ice.

Weeds are plants growing where humans do not want them.

Wetlands cover about 14 per cent of the land area of Canada, and are the natural habitat of over 600 species of plants, animals and insects. In addition to providing a home for these plants and animals, wetlands are an essential part of the environment because they prevent flooding, filter toxins, store groundwater and limit erosion. The most common wetland habitats are swamps, marshes, and bogs.