Central America, region of the western hemisphere, made up of a long, tapering isthmus that forms a bridge between North and South America. Central America, which is defined by geographers as part of North America, has an area of about 521,500 sq km (about 201,300 sq mi) and includes the countries of Guatemala, Belize, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama. The region has a population of approximately 36.4 million (2000 estimate).

CLIMATE
Temperatures in Central America, which is situated between the tropic of Cancer and the equator, vary principally according to altitude rather than latitude. Three main temperature zones are discernible. The tierra caliente ("hot country"), which extends from sea level to an altitude of about 915 m (about 3,000 ft), has average yearly temperatures of 24° C (75° F) or more; the tierra templada ("temperate country"), from about 915 to 1,830 m (about 3,000 to 6,000 ft), has a mean annual temperature of 18° to 24° C (65° to 75° F); and the tierra fría ("cold country"), from about 1,830 to 3,050 m (about 6,000 to 10,000 ft), has average yearly temperatures of 13° to 18° C (55° to 65° F). The Caribbean coast and eastern mountain slopes generally receive twice as much annual precipitation as the Pacific coast and western mountain slopes. The relative dryness of the Pacific slope is due to the presence of cold stable air caused by the cold California Current. This current, much like the Peru, or Humboldt, Current along the Peruvian coast, chills the air, thus preventing it from absorbing much water vapor and reducing the possibilities for precipitation. In contrast, the effects of the warm water of the Caribbean Sea allow the air to absorb abundant moisture, which is then carried by the prevailing easterly winds. Much condensation and rainfall occur as the winds flow up and over the high slopes of Central America. Rainfall is greatest along the Mosquito Coast of easternmost Nicaragua-San Juan del Norte receives about 6,350 mm (about 250 in) of rain per year. In October 1998 Hurricane Mitch savaged Central America, killing at least 11,000 people, leaving thousands more missing, and displacing more than two million others. Nicaragua and Honduras absorbed the brunt of the damage, but El Salvador, Guatemala, Belize, and other countries in the region also felt the effects of the storm. Some observers called Mitch the worst natural disaster ever to strike Central America.

VEGETATION
Central America is essentially a land bridge uniting two previously isolated ecosystems. As a result, a mixture of both North and South American plant and animal species is found here. The lowland rain forest of the Caribbean and Pacific coasts resembles the selva, or tropical rain forest, of South America. This is especially true below an elevation of about 1,000 m (about 3,280 ft), with large numbers of palms, tree ferns, lianas, and epiphytes (air plants) reflecting the high rainfall and humidity of the region. Vegetation at altitudes of about 1,000 to 1,600 m (about 3,280 to 5,250 ft) shows ties with North America. The pine and oak forests of these highlands are like those of the Mexican highlands. High-altitude regions of Guatemala contain grasses like those of Mexico and the United States, and at about 3,100 m (about 10,170 ft) in Costa Rica are tall grasses similar to those growing above the tree line in the Andes Mountains of South America.

ANIMAL LIFE
Most of the animal life of Central America is similar to that of South America, but some animals have ties with North America. The marley and opossum have links with South America, as do the jaguar, ocelot, jaguarundi, and margay, which are members of the cat family. In contrast, the puma, gray fox, and coyote are of North American origin. The armadillo, anteater, and sloth have ties to the south, deer to the north. The large manatee, an aquatic plant eater, survives in the isolated lagoons of eastern Central America. Other food sources are the large green turtle and the iguana. Central America provides a habitat for numerous snakes such as the boa constrictor and the bushmaster. Parrots, the quetzal, toucans, and fish are common; notable are the landlocked sharks of Lake Nicaragua.

THE PEOPLE
A substantial majority of the people of Central America are Native Americans or mestizos (people of mixed heritage, chiefly of Spanish and Native American descent). Along the narrow Caribbean coast blacks and mulattoes (people of mixed white and black-African backgrounds) predominate. About half of the people of Belize are of black-African or partly black-African ancestry. The great majority of Costa Ricans are of unmixed Spanish background, and approximately 90 percent of the inhabitants of El Salvador and Honduras are of mixed Spanish and Native American descent. About 45 percent of Guatemalans are Native Americans, and mestizos make up most of the rest of the country's population. About 70 percent of Nicaragua's and Panama's inhabitants are mestizos. Panama has a sizable black minority. In general, the Native American element is less apparent in the southern countries of Nicaragua, Costa Rica, and Panama

The population of Central America is concentrated in districts of dense settlement, separated by areas of sparse habitation. Population densities reach more than 385 persons per sq km (more than 1,000 per sq mi) in parts of the Meseta Central of Costa Rica, but vast areas of eastern Honduras and Nicaragua have fewer than 4 persons per sq km (fewer than 10 per sq mi). The rate of population increase in much of Central America is high; in 2004 Nicaragua had an annual growth rate of 1.97 percent; Guatemala, 2.61 percent; Costa Rica, 1.52 percent; and Panama, 1.31 percent. The population increase is principally the result of continuing high birth rates and falling death rates. Increasing political unrest, economic hardship, guerrilla warfare, and military repression have forced many rural residents into urban centers; thousands also decided to begin the long trek to the United States via Mexico. The people of Central America are becoming increasingly urbanized. In the mid-1990s about 45 percent of the inhabitants of El Salvador and Honduras and about 40 percent of Guatemalans were considered urban, while more than half the people of Panama and nearly two-thirds of Nicaragua's people lived in urban areas. In each country except Belize the national capital is the largest city; the biggest urban center of Belize is Belize City.