Peru Geography, Climate & Nature

Peru is on the central western coast of South America, facing the Pacific. It lies wholly in the southern hemisphere, though its northernmost extreme reaches to within about 3.3 kilometres of the equator, and it covers 1,285,216 square kilometres of land plus 5,000 square kilometres of water. It borders Ecuador and Colombia to the north, Brazil to the east, Bolivia to the south-east and Chile to the south, and claims an exclusive economic zone of 857,000 square kilometres.

Three sharply distinct zones

The costa, to the west, is a narrow and largely arid plain except where seasonal rivers have created valleys. Lima is on it, and it is desert fed by rivers off the Andes rather than by rainfall.

The sierra is the region of the Andes, and it includes the Altiplano plateau and the country's highest peak, Huascarán at 6,768 metres. Cusco, Machu Picchu and Lake Titicaca — shared with Bolivia and the highest navigable lake in the world — are all here, with many peaks above 6,000 metres.

The selva is a wide expanse of flat terrain under Amazon rainforest extending east, almost 60 per cent of Peru's territory and larger in the north than the south, holding the Amazon, Marañón, Huallaga and Ucayali rivers — and a small fraction of the population.

Why it is three and not eight

The three-region division is a Spanish administrative decision rather than a geographical one: the Spanish divided the territory into Coast, Highlands and Jungle for political reasons, and the division lasted until 1941, when the third General Assembly of the Pan American Institute of Geography and History approved eight natural regions instead. The eight describe the country better. The three are what everyone still uses.

Peru's three geographic zones each follow their own distinct climate pattern. The desert coast, including Lima, is mild and dry year-round, with a notably cool, overcast winter (June-September) caused by the cold Humboldt Current.

The Andean highlands have a dry season (May-September) with sunny days and cold nights, and a wet season (November-March) with regular afternoon rain.

The Amazon lowlands stay hot and humid year-round, with a somewhat wetter period from November to March.

Peru covers 1,285,216 square kilometres of western South America, reaching to within about 3.3 kilometres of the equator at its northern extreme while lying wholly in the southern hemisphere. It divides into three regions, and each is a different biology: the costa, a narrow and largely arid plain except where seasonal rivers cut valleys; the sierra, the Andes, including the Altiplano and Huascarán at 6,768 metres, the country's highest peak; and the selva, flat terrain under Amazon rainforest which is almost 60 per cent of the national territory and includes the Amazon, Marañón, Huallaga and Ucayali rivers.

The concentration at Manu

The single most striking fact: the Manu Biosphere Reserve is believed to have the highest concentration of bird species in the world — 1,000 species, one out of every nine on Earth, in one reserve. Manu is also where new mammals are still being described: a cloud-forest rodent of the spiny rat family was found there in January 2007.

National parks

In Peruvian national parks the exploitation of natural resources and human settlement are prohibited outright. The oldest is Cutervo, created in 1961 in Cajamarca, known for caves including San Andrés, home to the oilbird — a nocturnal bird in danger of extinction. Huascarán in Áncash is dominated by the country's highest mountain and holds Puya raimondii, the largest species of bromeliad in the world, which flowers once and then dies.

A useful caution about regions

The three-region division is administrative history rather than biology: the Spanish divided Peru into Coast, Highlands and Jungle for political rather than geographical reasons, and that division lasted until 1941, when the third General Assembly of the Pan American Institute of Geography and History approved a set of eight natural regions instead. The eight map the biology better; the three are what everyone still says.

Peru has over 1,800 species of bird — the second-highest number of any country in the world — of which about 120 are endemic. New species are still being added: 42 from Peru have been described to science in the last thirty years, and in January 2010 a new population of the very rare long-whiskered owlet was found. The rufous twistwing, a tyrant flycatcher first collected in 1990, was not rediscovered until 2002 and had no natural history recorded until 2003.

Manu, and why it matters

The Manu Biosphere Reserve is believed to have the highest concentration of bird species in the world: 1,000 species, one out of every nine on Earth. If you only understand one thing about Peruvian wildlife, it is that number.

Mammals

Over 500 mammal species, of which about 70 are endemic and about 109 threatened or endangered. The spectacular ones are the jaguar, puma and spectacled bear; the rare endemics include the yellow-tailed woolly monkey. Many live in the canopy, which is why jungle lodges build towers — the animals are above you, not beside you. The Pacific holds sea bass, flounder, anchovies, tuna, crab, lobster, shellfish and seals.

Reptiles and amphibians

Around 300 reptile species, about 100 of them endemic — including giant anacondas and caimans alongside many snakes, lizards and turtles. And about 380 species of frog, several of which are easy to see on a night walk in the lowland rainforest at Tambopata, Manu or Iquitos. Ten new frog species were described from the cloud forests of the Peruvian Andes in two years.

Plants

Huascarán National Park holds Puya raimondii, the largest bromeliad species in the world. Cutervo, the oldest national park, protects caves housing the oilbird, a nocturnal species in danger of extinction.

No species list beyond what the sources opened for this page support is asserted here.