Tropical rainforests are rainforests in the tropical regions of the world. These rainforests receive a high volume of annual rainfall, and nearly every month receives at least 60 mm rainfall. These rainforests have rich biodiversity and nearly 40% to 75% of all species on Earth inhabit these forests. Fauna of these rainforests includes the jaguar, tapir, okapi, boa constrictor, African gray parrot, keel-billed toucan, crowned eagle, three-toed sloth, spider monkey, large flying fox, king colobus, and more. In this article we discuss the different layers of the tropical rainforest and some of the animals living in these layers.
21. Forest Floor
The forest floor is the rainforest’s bottom-most layer which receives only 2% of the sunlight. Thus, plants growing here are adapted to the low light conditions, and the forest floor is relatively clear of vegetation. Thus, relatively larger animals of the tropical rainforest like the okapi, the tapir, the Sumatran rhinoceros, etc., inhabit the forest floors of rainforests. A large number of reptiles, insects, and amphibians also occur in this layer. Decaying plant and animal matter collect in the forest floor where they are decomposed by microbes like bacteria and fungi.
The okapi (Okapia johnstoni) is a unique mammalian species that is native to tropical forests of the Democratic Republic of the Congo in Central Africa. Although the okapis bear distinct zebra-like markings on their limbs, they are more closely related to giraffes. Okapis are diurnal and solitary in nature. These tropical rainforest animals feed on tree leaves and buds, fruits, ferns, and fungi.
The tapir (Tapirus sp.) is a pig-like herbivorous mammal with a short, prehensile snout. These tropical rainforest animals are found in forests of South and Central America as well as Southeastern Asia.
18. Sumatran Rhinoceros
One of the five extant rhino species today, the Sumatran rhinoceros (Dicerorhinus sumatrensis) inhabits the tropical forests of Borneo and Sumatra. It is the smallest rhinoceros species in the world and has two horns. The Sumatran rhinoceros is a critically endangered species as it has been hunted extensively for its horns which are used to prepare traditional medicines in China and Vietnam.
17. Western Lowland Gorilla
The Western lowland gorilla (Gorilla gorilla) is found in the forests of central Africa. These animals are extremely wise and can fashion out tools to gather more food using natural objects. This tropical rainforest animal is today critically endangered. Hunting for bushmeat and logging in gorilla habitats are the two primary threats to these gorillas.
16. Understory Layer
The tropical rainforest layer between the forest floor and the canopy is the understory layer, and it receives only about 5% of the sunlight. A large number of small mammals, birds, reptiles, and predators like the jaguar inhabit this layer. Shade-tolerant shrubs, small trees, woody vines, and herbs comprise the vegetation of this layer. Plants growing here seldom reach 10 feet in height and usually have broad leaves to provide greater surface area for photosynthesis.
The jaguar (Panthera onca) is the biggest cat species living in the Americas and is the third largest in the world after the lion and the tiger. The jaguar prefers to inhabit the rainforests of the Americas and is found across much of Central America and south to northern Argentina and Paraguay. The range of this species also extends north into Mexico. The jaguar closely resembles the leopard but is sturdier and larger than the latter. The jaguar is a solitary, apex predator of the ecosystem it inhabits.
14. Poison Dart Frog
Though the name sounds deadly, only about three species of this frog are actually lethal. The golden arrow frog (Phyllobates terribilis) is the most dangerous among the three. These frogs all possess vibrant colors of gold, red, green, blue, and yellow which is a tactic to ward off predators. This feature is known as aposematic coloration.
13. South-American Coati
Also known as the ring-tailed coati (Nasua nasua), it is an animal that inhabits the rainforests of South America. The coatis are found in the lowland rainforests east of the Andes from Colombia to the Guianas to Uruguay and northern Argentina.
12. Boa Constrictor
The boa constrictor (Boa constrictor) is a massive snake that is found in forests throughout the Americas and also the Caribbean islands. Though the boa constrictor is found in a wide variety of habitats, it prefers the rainforests in its range due to the high humidity and temperatures of such habitat. Also, rainforests provide sufficient cover and plenty of prey options to these snakes.
11. Canopy Layer
The canopy is the most distinctive layer of the rainforest forming a roof over the forest floor and the understory layer. A majority of the largest trees of the rainforest, growing up to 30 to 45 m in height, are found in this layer. Broad-leaved evergreen trees dominate the forest canopy, and a rich flora of orchids, mosses, lichens, bromeliads, etc., are supported by the canopy layer making it the densest part of the rainforest. Over 20 million arthropod species and a large number of avians inhabit this forest layer. Mammals, invertebrates, and reptiles are also found here.
10. African Gray Parrot
African gray parrots are medium-sized, gray, black-billed birds found in equatorial Africa. The birds are currently classified as vulnerable and number between 120,100 and 259,000.
9. Keel-Billed Toucan
The keel billed toucan (Ramphastos sulfuratus) is found in the rainforests of Latin America. In these forests, it roosts in holes of trees in the rainforest canopy layer, often with other toucans. The crowded roosting places demand that the toucans tuck their beaks and tails under their bodies to save space.
8. Spider Monkey
Spider monkeys are found in the Central and South American rainforests from Mexico to Brazil. All the seven species of these monkeys are threatened to some extent. These highly social creatures live in large groups of about 35 individuals and split into smaller groups to feed during the day.
7. Three-toed Sloth
The three-toed sloths are arboreal mammals found in South and Central America. These tropical rainforest animals are named so for their slow gait which is an adaptation to conserve energy. These sloths have a size of a small dog or a big cat and three clawed toes on each limb.
6. Great Hornbill
The great hornbill or Buceros bicornis is a vulnerable species found in forests in parts of the Indian subcontinent and Southeast Asia. It is one of the largest species of the hornbill family. Predominantly frugivorous, the bird also feeds on small mammals, birds, and reptiles occasionally. It can live for around 50 years in captivity and features prominently in the rituals and cultures of locals in areas where it is found.
The kinkajou is one of the animals in the tropical rainforest which though mistaken for monkeys or ferrets, are related to none of them. The kinkajou is native to the Central and South American rainforests. These animals are nocturnal, frugivorous, and arboreal in nature. Unfortunately, they are hunted for the pet trade and for their fur.
4. Emergent Layer
The emergent layer has few giant trees that reach heights up to 45 to 55 m or even higher. Thus, these trees appear to emerge over the canopy layer. The trees of this layer are well adapted to withstand the strong winds and hot temperatures above the canopy. When such emergent layer trees collapse, it forms gaps in the canopy, allowing sunlight to reach the lower layers of the rainforest.
3. Crowned Eagle
The crowned eagle (Stephanoaetus coronatus) is a massive and ferocious bird of prey that is found in the emergent layer of the rainforests. The eagle primarily feeds on mammalian prey like small ungulates, small primates, birds, and lizards. It is one of the most powerful eagles of Africa but is now classified as Near Threatened by IUCN due to the large-scale destruction of its habitat.
2. King Colobus
The king colobus (Colobus polykomos) is one of the animals of the tropical rainforest that is found in the rainforests of Africa in the countries of Senegal, Liberia, Guinea, Sierra Leone, Guinea-Bissau, and the Ivory Coast. The king colobus lives in the emergent layer of these forests but eats primarily on the ground. 3 to 4 females and 1 to 3 males of this primate species live together in one group.
1. Large Flying Fox
The large flying fox (Pteropus vampyrus) is one of the largest species of bats in the world. It lives in the canopy layer of the rainforests where it feeds exclusively on nectar, fruits, and flowers. Though these bats lack the ability to echolocate, it uses its keen eyesight to detect food sources.