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© J.J. Huckin / WWF-US
Up in the trees and under the water

Pink dolphins, jaguars, the slow-moving sloths, armour-plated armadillos and the peculiar anteaters, all have their place in different parts of the Amazon - along with about 420 other mammals that are found there1. But the majority, it turns out, are rodents and bats.

What mammals will you find in the region?

Jaguar (Panthera onca)2

Revered and feared, the jaguar is the biggest cat of the American continent. Despite a wide distribution in rainforests, flooded swamp areas, grasslands, thorn scrub woodlands and dry deciduous forests, it is scattered in these places and generally decreasing in numbers outside of the Amazon rainforest, its main stronghold.

The jaguar's shape and agility makes it particularly well adapted to swimming, climbing and crawling, not to mention sprinting at incredible speeds.

Its strength allows it to capture a variety of species. Large-sized ungulates such as deer are preferred, but peccaries and caimans also can be part of the menu. Its jaws and teeth are so powerful, that it can literally bite through the shell of a turtle.

Today, things have changed. Persecution, degradation of the jaguar's habitat, and decrease in its prey are thought to have reduced the species population to less than 50,000 mature breeding individuals in the wild.

While commercial hunting and trapping of jaguars for their pelts has declined drastically since the mid-1970's through public information campaigns and trade controls, the species is still a victim of ranchers, who kill it because it preys on cattle.

The jaguar is classified as Near Threatened by the IUCN Red List of Threatened Species.

When the Mayan and Inca civilizations ruled, the jaguar was revered as a divine creature. Aztecs even fed the hearts of sacrificed victims to them. In the Amazon, it was believed that the jaguar’s eyes have a connection to the spirit world.3

Tapir (Tapirus terrestris)4

Another great swimming mammal, the tapir is found in lowland tropical and subtropical moist forests, with a preference for moist, wet or seasonally inundated areas. The combined impacts of deforestation, hunting and competition from domestic livestock have led to a reduction of its population.

In addition to its swimming abilities, the tapir can reach fairly quick speeds on land. Like many tropical mammals, tapirs are mostly active at night. Adults can reach about 2 m and over 227 kg. Tapirs eat leaves, fruit, grass and aquatic plants.

Deforestation is an ongoing threat in several places where the species is found. Hunting may also reduce the population even further.

The tapir is classified as Vulnerable by the IUCN Red List of Threatened Species.

Giant otter (Pteronura brasiliensis)

The world's largest otter is found throughout the Amazon River Basin, where the combined impacts of habitat loss and pollution pose risks to the long-term survival of the species.

The giant otter is almost 1.5 m long, with an additional metre provided by its tail. Its webbed feet, semi-flattened tail and reddish-brown, water-repellent fur make it particularly well-suited to swimming. It is found in groups of 3 to 9 individuals, foraging in tributaries (especially around oxbow lakes), and in slow-moving rivers, lakes and swamps. The giant otter feeds on fish, mammals, birds and other vertebrates.

While otter fur trade has decreased, illegal hunting is still an ongoing problem. In addition, habitat loss and pollution from mining activities are a concern. Otters may also be victims of fishing nets in rivers.

Giant otters are classified as Endangered by the IUCN Red List of Threatened Species5, and are listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

Amazon or pink river dolphin (Inia geoffrensis)6

The pink river dolphin (Inia geoffrensis), contains two subspecies: I.geoffrensis geoffrensis in the Amazon and I. geoffrensis humboldtianain the Orinoco.


Also known as the boto, the Amazon river dolphin is one of the world's three dolphins that are constrained to freshwater habitat. The species is widely distributed throughout much of the Amazon and Orinoco river basins. Like its relatives elsewhere, the boto's habitat is threatened by river development projects: Hydroelectric and irrigation schemes separate rivers in bodies of waters, which may reduce the species range and its ability to breed.


The boto is a pale pink colour and is different from other dolphins in that it has a flexible neck, which allows it to move its head left and right. It has a long snout, a rounded head and small dorsal fin, with overall length varying from 2 to 2.5 m. The boto feeds on fish and other aquatic organisms such as turtles and crabs.


The pink river dolphin is found in lowland fast flowing, whitewater rivers, clearwater or blackwater rivers. Furthermore, the species is present in the largest tributaries, lakes, confluences and seasonally flooded forests. It depends on healthy fish populations for its survival.


Historically, the boto has been spared human persecution because of the belief that it has special powers. Today however, it is increasingly viewed by fishermen as an unwanted competitor for fish. The boto can also get tangled up in fishing nets, or suffer wounds by colliding with boats. To date however, no major reduction of their range has been observed.


Another threat for the boto comes from the petroleum industry in the Amazon and Orinoco basins. In Colombia, armed groups have blown up oil pipelines, causing irreparable pollution to aquatic ecosystems where the species is found.

The boto is classified as Vulnerable by the IUCN Red List of Threatened Species7, and listed on Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).


Another river dolphin species is the tucuxi or grey dolphin. It is darker and smaller than the boto, with a shorter snout, and a distinctive triangular dorsal fin. The tuxuci is found in larger groups and unlike the boto, jumps out of the water.8

Did you know...

That the pink river dolphins are generally found in groups of 2 to 4 individuals, but from time to time it could be solitary?
They also have a poor vision and they rely on an internal sonar system which help them to manoeuvre under water and find food.

 Da Silva et al. 2005. The Fate of the Amazonian Areas of Endemism. Conservation Biology, 19 (3), 689-694

2 Cat Specialist Group 2002. Panthera onca. In: IUCN 2004. 2004IUCN Red List of Threatened Species. Accessed 06 October 2005.

3 ThinkQuest. Animals of the Amazon. Accessed: 06/10/05

4 Downer, C. & Castellanos, A. 2002. Tapirus terrestris. In: IUCN 2004. 2004 IUCN Red List of Threatened Species. Accessed: 06 October 2005.

5 Groenendijk, J., Hajek, F. & Schenck, C. 2004. Pteronura brasiliensis. In: IUCN 2004. 2004 IUCN Red. List of Threatened Species.Accessed: 11 October 2005.

6  Groenendijk, J., Hajek, F. & Schenck, C. 2004. Pteronura brasiliensis. In: IUCN 2004. 2004 IUCN Red. List of Threatened Species. Accessed 11 October 2005.

7 Cetacean Specialist Group 1996. Inia geoffrensis. In: IUCN 2004. 2004 IUCN Red List of Threatened Species. Accessed 13 October 2005.

8  Goulding, 1993 in Kircher, 1997