Andes

The World's Longest Mountain Chain

A group of vicugnas in the Andes mountains of Ecuador.
A group of vicugnas in the Andes mountains of Ecuador. Photo © Westend61 / Getty Images.

The Andes are a chain of mountains that extends 4,300 miles along the west coast of South America and bisects seven countries—Venezuela, Columbia, Ecuador, Peru, Bolivia, Chile, and Argentina. The Andes are the longest chain of mountains in the world and include many of the highest peaks in the Western Hemisphere. Although the Andes are a long mountain chain, they are also narrow. Along their length, the east-to-west breadth of the Andes varies between about 120 and 430 miles wide.

The climate throughout the Andes is highly variable and depends on latitude, altitude, topography, precipitation patterns, and proximity to the ocean. The Andes are divided into three regions—the northern Andes, the central Andes and the southern Andes. Within each region there is much variation in climate and habitats. The northern Andes of Venezuela and Colombia are warm and wet and include habitats such as tropical forests and cloud forests. The central Andes—which extend through Ecuador, Peru, and Bolivia—experience more seasonal variation than the northern Andes and habitats in this region fluctuate between a dry season and a wet season. The southern Andes of Chile and Argentina are divided into two distinct zones—the Dry Andes and the Wet Andes.

There are about 3,700 species of animals that live in the Andes including 600 species of mammals, 1,700 species of birds, 600 species of reptiles, and 400 species of fishes, and more than 200 species of amphibians.

Key Characteristics

The following are the key characteristics of the Andes:

  • longest mountain chain in the world
  • includes the Atacama desert, the driest desert in the world
  • includes the Andean Plateau, the second-highest plateau in the world
  • located on the Pacific Ring of Fire
  • includes of the highest active volcano in the world, Ojos del Salado, which lies on the border of Argentina and Chile
  • supports a number of rare and endangered species including short-tailed chinchillas, Andean flamingos, Andean condors, spectacled bears, Junin rails, and Titicaca water frogs

Animals of the Andes

Some of the animals that inhabit the Andes include:

  • Alapca (Vicugna pacos) - The alpaca is a domesticated species of even-toed hoofed mammal that belongs to the camel family. Alpacas are native to South American. They are kept in herds in the high altitude plateaus in Peru, Bolivia, Ecuador, and northern Chile. Alpacas are grazers that feed on hay and grasses.
  • Andean condor (Vultur gryphus) - The Andean condor is found throughout the Andes, although it is far less common in the mountain ranges of Venezuela and Columbia. Andean Condors inhabit grasslands and alpine habitats up to 16,000 feet. It prefers open habitats where it can locate carrion as it soars above.
  • Short-tailed chinchilla (Chinchilla chinchilla) - The short-tailed chinchilla is one of just two species of chinchillas alive today, the other being the long-tailed chinchilla. Short-tailed chinchillas are an endangered species of rodent that once inhabited areas of the central and southern Andes. The species was heavily exploited for its fur and as a result their numbers declined drastically. Short-tailed chinchillas are currently classified as critically endangered on the IUCN RedList.
  • Andean mountain cat (Leopardus jacobita) - The Andean mountain cat is a small cat that inhabits high montane regions of the central Andes. The Andean mountain cat is rare, with less than 2,500 individuals remaining in the wild.
  • Titicaca water frog (Telmatobius culeus) - The Titicaca water frog is a critically endangered frog that is endemic to Lake Titicaca. Titicaca water frogs were once common but have declined due to hunting, pollution, and predation by trout that have been introduced to the lake.
  • Andean goose (Chloephaga melanoptera) - The Andean goose is a large sheldgoose with black and white plumage, a pink bill, and orange legs and feet. The Andean goose inhabits elevations of the Andes above 9,800 feet in Peru, Bolivia, Argentina, and Chile.
  • Spectacled bear (Tremarctos ornatus) - The spectacled bear is South America's only native species of bear. It inhabits forested areas of the Andes mountain range including Venezuela, Colombia, Ecuador, Bolivia, and Peru. Spectacled bears have black fur, keen eyesight, and distinctive golden-colored rings of fur framing their eyes.