Habitats Threats and Conservation E very major kind of environment can be found in the Americas from icy Arctic wastes to hot and humid rain forests Since different habitats provide food and shelter for different kinds species of animals this variety means that a huge range of species lives in North and South America from top predators such as gray wolves and American alligators to tiny hummingbirds frogs and invertebrates While it is true to say that the landscapes of the Americas still support thousands of species many are threatened by changes in land use especially the clearance of large areas of forest and the conversion of natural grasslands to agriculture Human disturbance of sensitive animals for example marine turtles on the Mexican beaches where they lay their eggs is also a problem And pollution caused by oil spills such as those off the Galápagos Islands and in the Gulf of Mexico kill animals and damage ocean environments However most governments now take measures to protect their wildlife and have established protected areas where development is restricted Varied Habitats In the far north much of Alaska and northern Canada is covered with tiny shrubs and herbs this landscape is called tundra Despite cold temperatures and limited sun for much of the year it supports many breeding birds They arrive from warmer regions in spring to breed when there is an abundance of insect life to eat before departing in fall Mammals such as polar bears caribou and musk oxen also live there Coastal waters provide feeding for walruses and whales Further south there are vast areas of coniferous forest called taiga which are home to grizzly bears elk and deer in addition to grouse owls and many other birds In the eastern United States large tracts of deciduous forest remain Red foxes gray wolves flying squirrels and millions of song birds live in these forests Some of these animals need large areas of unbroken woodland and these species have declined as forest has been broken up by highways and other 4 developments To the west the Great Plains stretch for hundreds of miles to the foothills of the Rocky Mountains These grasslands shortgrass prairie in the west and tallgrass prairie farther east were once home to huge numbers of American buffalo or bison but large-scale hunting in the late 19th century reduced the population of these large mammals from more than 60 million to just a few thousand Protection in preserves has since allowed their numbers to increase but to nowhere near their former status Much of the natural grassland of the Great Plains has been plowed for agriculture However the Great Plains still have more than 80 species of mammals including black tailed prairie dogs 450 different kinds of birds 57 species of snakes lizards and turtles and some 15,000 insect species In the southwest United States and northern Mexico huge dry deserts such as the Mojave Chihuahua and Sonora are important for many reptiles birds and even amphibians that are able to take advantage of occasional rain The mountainous spine of Central America running from Mexico to Panama was once covered by mostly damp forest which supported a great variety of animal life especially amphibians and birds but also monkeys bears and other mammals Much of this forest has
HABITATS THREATS AND CONSERVATION been cleared for agriculture sometimes resulting in erosion of the land as well as the destruction of habitats for the animals Elsewhere however national parks protect the remaining forest Monteverde Cloud Forest in Costa Rica is an important example although protection here was not enough to save the golden toad from extinction The forests and high grasslands of the tropical Andes Mountains running from western Venezuela through Colombia Ecuador Bolivia and Peru contain one-sixth of all plant species on Earth despite covering The Florida Everglades provide a home for several endangered species including American crocodile Florida panther and wood stork only 1 percent of its land surface Forest cloaks the lower slopes on both sides of this mountain range becoming damp cloud forest and elfin forest forest with very small trees in the area just below the tree-line Above the tree-line is open grassland called páramo Each of these habitats is home for different sets of mammals birds amphibians and invertebrates many 5
National Parks in the United States Many areas of North and South America are now protected as national parks This means that there are strict limits on any changes that can be made to the natural environment It may be forbidden to cut down trees drain wetlands or build towns on areas of grassland for example Some preserves cover shorelines and areas of oceans giving protection to whales fish and nesting turtles In the United States the National Park Service was set up in 1916 in an effort to preserve wildlife habitats for the enjoyment of future generations However the world’s first national park at Yellowstone was established as long ago as 1872 to protect among other things populations of American bison bobcats mountain lions beavers sandhill cranes and cutthroat trout Yosemite National Park in California straddles the Sierra Nevada Mountains and has more than 250 species of fish amphibians reptiles birds and mammals In the same state Death Valley National Park is one of the hottest and driest places on Earth This desert preserve has herds of bighorn sheep as well as bobcats mountain lions and many snakes and lizards and a surprising number of different species of birds In contrast the Everglades National Park in Florida is very wet with an ample supply of fresh water and important populations of water birds snapping turtles American alligators and Florida panthers of them rare More than 1,700 bird species live there almost one in five of all those found on Earth 600 of these are found nowhere else This is also the most important area on the planet for amphibians with 980 species known most of them found in the Andes and nowhere else There are surely many more species of frogs and salamanders yet to be discovered And there are probably thousands of invertebrates that scientists have yet to describe In some areas deforestation has been a problem although forests on the steepest slopes have mainly been left untouched The Amazon To the east the Amazon rain forest is probably the single most important region for animals anywhere on Earth It is as large as the area between the Rocky Mountains and the Atlantic Ocean and its trees are home to a bewildering array of invertebrates birds and mammals Fish and amphibians live in its mighty rivers including the Amazon itself while reptiles occupy river banks and the forest itself However large swaths of the forest have been cleared for highways human settlements and cattle ranches This deforestation accelerated after 1972 when the Trans Amazonian Highway was opened allowing developers to reach deeper into the forest Between 1991 and 2000 the total area of Amazon forest that had been 6 cleared increased from 160,000 square miles 415,000 km2 to 227,000 square miles 587,000 km2 roughly the size of the Canadian province of Manitoba Most of this forest was replaced with pasture for cattle and many species of wild animals lost their homes The total area of forest is now thought to be only four fifths of its size in 1970 The good news is that the rate of clearance slowed dramatically after 2004 and there are important protected areas such as Tumucumaque National Park in northern Brazil which is the biggest area of protected tropical forest in the world Not all of South America is covered by forests Also important are the continent’s wetlands Those of the Llanos in Venezuela are flooded in the wet season when they are important for giant anteaters caimans anacondas and many wading birds Farther south in Brazil the Pantanal wetlands also have wading birds and several species of cats Grasslands are also important South of the Amazon rain forest where the climate is too dry for forest growth is the cerrado of Brazil with animals such as giant armadillo maned wolf jaguar puma and many reptiles In Argentina the great expanses of the pampas grasslands support endangered pampas deer and pampas cats San Rafael waterfall in Ecuador is surrounded by rain forest that is home to animals both common and endangered
