The greatest biodiversity in Bolivia – and indeed pretty much anywhere on earth – is found on the well-watered eastern slopes of the Andes, where the mountains plunge down into the Amazon basin trough a succession of different ecological zones, from the high cloud forest or ceja de selva – whose gnarled trees are festooned with hundreds of different kinds of orchid – to the lowland tropical rainforest. With mighty trees soaring to create a canopy over 30 m above the ground, the rich and luxuriant vegetation of the Amazon rainforest is in fact extremely fragile. The soils beneath forest are generally very poor, and the forest ecosystem flourishes only through a complex system of nutrient cycling involving plants, insects and fungi, so if the forest is cleared, the quality of the land disappears rapidly.
The rainforest ecosystem supports an incredible variety of plant and animal life: over six thousand species of plant have been recorded in one small tract of forest, and the Amazon’s unidentified species of insect alone are thought to outnumber all earth’s known animal species. Seeing wildlife in the Amazon is not easy, nevertheless on any rainforest trip you’re likely to see innumerable birds including brightly colored toucans, parrots, tanagers, kingfishers, trogons and macaws of various kinds. Several of Bolivia’s more than thirty monkey species are also easy to spot including long-limbed spider monkeys, howler monkeys, chattering squirrel monkeys and diminutive tamarinds and titis. Larger mammals include the capybara, the world’s largest rodent, the tapir, a lumbering beast the size of a cow with an elephant-like nose, herds of peccary, a kind of wild boar, as well as giant armadillos and sloths. All of these are potential prey for a range of wild cats, the largest which is the jaguar. The rivers of the Bolivian Amazon teem with fish, from giant catfish to the piranha. You’ll also see turtles and cayman crocodiles of various kinds, as well as giant anacondas and pink freshwater dolphins.
Many of the larger animals are easier to see as you head east through the Bolivian Amazon, where the dense rainforest gives way to the more open vegetation of the Llanos de Moxos, where seasonally flooded grasslands are interspersed with islands of forest and patches of swamp. Here, you’re more likely to spot creatures such as giant anteaters and rheas (large flightless birds similar to ostriches), or even maned wolves.
To the south of the Bolivian Amazon the forest ecology gradually changes as it adapts to lower and more seasonally varied rainfall. The Chiquitania region east of Santa Cruz has some of the world’s largest remaining tracts of tropical dry forest, which is home to many of the same animal species, plus a great variety of bird life. Heading further south, this forest gets drier still as it merges into the Gran Chaco. This vast arid wilderness also supports abundant wildlife, including jaguar, puma, and deer, at least ten different kinds of armadillo, and even an endemic species of wild boar, the Chacoan peccary.
The contrast between the Chaco and the far east of Bolivia could not be greater. Here, the plains and rainforest of Amazonia gradually give way to the immense watery wilderness of the Pantanal, the world’s largest wetland ecosystem, which stretches far across the border with Brazil and is home to many Amazonian species. Though it does not match the overall biodiversity of the rainforest, the Pantanal is unique in terms of the sheer abundance of wildlife. Concentrations of fauna here are thought to be the highest in all the Americas, comparable to the densest wild animal populations in Africa – one estimate puts the number of caymans in the region at ten million. It’s also one of the best places to see jaguars and the highly endangered giant river otter. Bird life too is extraordinarily abundant, including innumerable water birds such as roseate spoonbills, herons, egrets and the massive jaburu stork, the symbol of the Pantanal, and at least fifteen species of parrot, including the highly endangered hyacinth macaw.
Bolivia is one of the best places on the continent to observe wildlife, and even seasoned wildlife watchers will be impressed by the diversity on show.
The distribution of wildlife is dictated by the country’s geography and varies considerably from region. The Altiplano is home to vicuñas, flamingos and condors; the Chaco to secretive jaguars pumas and peccaries ; the Pantanal provides refuge for giant otters, marsh deer and waterbirds; and the Amazon Basin contains the richest density of species on earth, featuring an incredible variety of reptiles, parrots, monkeys, hummingbirds, butterflies, fish and bugs (by the zillion!).
Of course, the animals that steal the show are the regional giants: the majestic jaguar, the continent’s top predator; the elephant-nosed tapir (anta) and the giant anteater. The ostrich-like rhea or ñandú, the continent’s biggest bird, is here too and it can be surprisingly common in some areas. You may even be lucky enough to spot breathtaking Andean condor – revered by the Inca – soaring on mountain thermals. River travelers are almost certain to see capybaras (like giant aquatic guineapigs) and caimans (alligators). It’s not usual to see anacondas in the rivers of the department of Beni, and a spot of piranha fishing is virtually an obligation for anybody spending time in the Amazon.
Overland travelers frequently see armadillos, foxes, jochis (agoutis) and the gray-faced, llama- like guanaco. Similar, but more delicately proportioned, is the fuzzy vicuña, once mercilessly hunted for its woolly coat but now recovering well. You won’t have to work quite as hard to spot their domesticated relatives, the llama and the alpaca.
Because of its enormous range of altitudes, Bolivia enjoys a wealth and diversity of flora rivaled only by its Andean neighbors. No fewer than 895 plants are considered endemic to the country, including 16 species of passion fruit vines and at least three genera of orchids.
In the overgrazed highlands, the only remaining vegetable species are those with some defense against grazing livestock or those that are not suitable for firewood. Much of what does grow in the highlands grows slowly and is endangered, including the globally threatened genus of polylepis shrubs which form dense, low forests at altitude of up to 5300m, making them the highest growing arborescent plants in the world.
The most upper slopes of the Yungas are characterized by dwarf forest. Further down the slopes stretches the cloud forest, where the trees grow larger and the vegetation thicker. Northern Bolivia’s lowlands consist of islands of true rainforest dotted with vast wetlands and endangered cerrados, while the Amazon Basin contains the richest botanical diversity on earth.