Red howler monkeys. Photo by Sam Abell, 2010.

The Amazon rainforest contains a large portion of the world’s mammal species. To date, 427 mammals species have been documented in the Amazon [1], though this number is likely to increase as scientific expeditions record new species. According to Patterson [2], one new genus and eight new species of Neotropical mammals are discovered each year. Most of the mammalian species in the Amazon are rodents and bats, but there are also more unusual species, including swimming mammals like the Tapir (Tapirus terrestris), Giant otter (Pteronura brasiliensis) and the pink river dolphin (Inia geoffrensis; see Freshwater Species).

The most threatened mammal species in the Amazon are the primates. More than 100 species of primates are found within Brazil [3], many of which are found nowhere else in the world. Primates in the Amazon exist in many forms, from long-limbed spider and wooly monkeys, to smaller capuchin and squirrel monkeys, as well as marmosets and tamarins. Primates help to maintain biological diversity by serving as pollinators and seed dispersers within the tropical rainforest. A single spider monkey can disperse over 195,000 seeds over the course of one year [4], greatly contributing to rainforest regeneration. Of the 199 taxa of primates in the Neotropics, however, 35% are listed as threatened by the International Union for the Conservation of Nature (IUCN).

The Jaguar is easily one of the Amazon’s most recognized species. The largest felid in South America, the jaguar helps regulate prey population sizes [5]. It can weigh up to 300 pounds and has one of the strongest bites of any cat species on the planet, capable of crushing armadillo armor. Despite its large range throughout South America, the jaguar is listed by the IUCN as ‘Near Threatened’ due to hunting pressure imposed by farmers and ranchers throughout the Amazon. This top predator faces decline as food sources become restricted by habitat fragmentation and human encroachment [6].

A family of capybaras. Photo by Sam Abell, 2010.

Mammals often traverse large habitat ranges, providing a buffer from small-scale habitat destruction. However, habitat fragmentation can disrupt migratory pathways in the Amazon, stressing populations of migrating mammals. Over the next several decades, forest cover in the Amazon is predicted to decrease by as much as 50% [7], threatening many of the region’s mammal species. While large conservation areas such as parks and concessions are critical in establishing and maintaining mammal habitat, migratory corridors are also important to allow unrestricted movement between mammal populations to maintain genetic diversity. Infrastructure projects such as the Interoceanic Highway obstruct such corridors, while conservation organizations work to mitigate impacts of roadways on mammal populations.

  1.     World Wildlife Fund. (2010). Amazon Alive: A Decade of Discovery 1999-2009.
  2.     Patterson, B. D. (2000). Patterns and trends in the discovery of new Neotropical mammals. Diversity and Distributions, 6, 145-151.
  3.     Costa, L. P., Leite, Y. L. R., Mendes, S. L. and Ditchfield, A. D. (2005). Mammal Conservation in Brazil. Conservation Biology, 19(3), 672-679.
  4.     Link, A., and Di Fiore, A. (2006). Seed dispersal by spider monkeys and its importance in the maintenance of Neotropical rainforest diversity. Journal of Tropical Ecology, 22, 235-246.
  5.     Soisalo, M. K., and Cavalcanti, S. M. C. (2006). Estimating the density of a jaguar population in the Brazilian Pantanal using camera-traps, and capture-recapture sampling in combination with GPS radio-telemetry. Biological Conservation, 129, 487-496.
  6.     Nunez, R., Miller, B., and Lindzey, F. (2000). Food habits of jaguars and pumas in Jalisco, Mexico. Journal of Zoology, 252, 373-379.
  7.    Laurance, W. F., et al. (2001). The future of the Brazilian Amazon. Science, 291, 438-439.

Support the Amazon Aid Foundation Today