Monkey frog (Phyllomedusa bicolor) in the rainforest of Peru. (Photo by R. Butler)
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AMPHIBIANS AND REPTILES
AMPHIBIANS (pictures, news)
Frogs are overwhelmingly the most abundant amphibians in the rainforest. Unlike temperate frogs that are mostly limited to habitats near water, tropical frogs are most abundant in the trees, and relatively few are found near bodies of water on the forest floor. The reason for this is quite simple: frogs must always keep their skin moist since almost half of their respiration in carried out through the skin. The high humidity of the rainforest and frequent rainstorms gives tropical frogs infinitely more freedom to move into the trees and escape the many predators of rainforest waters.
The differences between temperate and tropical frogs extend beyond their habitat. Whereas nearly all temperate frogs lay their eggs in water, the majority of rainforest species place eggs in vegetation or lay them in the ground. By leaving the water, frogs avoid egg-predators like fish, shrimp, aquatic insects, and insect larvae. Several species of frogs, including the American glass frogs, lay their eggs on vegetation that overhangs water. The humid climate keeps the eggs moist and when the tadpoles hatch they drop into the water below. Glass frogs are also interesting because they are transparent except for their visible organs and the faint yellow spots that some species possess. These yellow spots resemble a cluster of the frog's eggs, enough to fool predators. Other frog species develop fully into froglets within their eggs, and emerge as fully formed frogs, thus by-passing the tadpole stage altogether.
REPTILES (pictures, news)
When many people think of the "jungle," they think of huge deadly snakes; but this is not the case in the canopy where very few species pose any threat to humans. The majority of canopy snakes are constrictors or mildly venomous species and are rarely encountered by humans. Even in the canopy, chances are you will not see many snakes, since numerous species camouflage themselves like leaves and vines.
The best known venomous canopy-dwelling snake is the eyelash viper of the New World which exists in several different color forms including yellow, green, olive, and orange. The eyelash viper is so named for the presence of small horned scales above the eye. Also found in the canopy are various constrictors of the Boa family which use their strong muscles to constrict their prey to death.
In addition to snakes, the forest canopy contains lizards. Iguanas are large greenish lizards of the New World, which have the unique ability to drop over 60 feet (18 m) from canopy trees unharmed. Their strong tail is used for balance during the fall and catching branches during the descent to break the impact of the fall. Iguanas often inhabit limbs that overhang rivers so they are able to escape predators by dropping into the river and waiting submerged for over 30 minutes. Iguanas may attain a length of six feet (1.8 m), though they are generally smaller. Iguanas have the ability to undergo a small color change to better blend into their surrounding environment. But the true color-change artists of the forest are the chameleons—of which every forested continent has its own. Chameleons are lizards that have the ability to rapidly change their colors to match their surroundings, although they tend to change more in accordance with their emotions. The Old World or true chameleons of Africa and Madagascar (pictures) have the best color-change ability and will often assume bright orange, purple, and blue coloring to reflect their mood. South America has the anole, a much less spectacular chameleon, while Asia has the agamas.
INVERTEBRATES (pictures, news)
Insects are the most successful rainforest animals as demonstrated by their tremendous diversity. Insects are so ubiquitous that they have filled many niches usually occupied by other animals. For example, some postulate that in South America the role of the forest elephant is filled by army ants. In the rainforest canopy, insects abound: a study of the rainforest canopy in Peru with 500 cubic meters of foliage (about the size of a two-car garage) found more than 50 species of ants, 1,000 beetle species, 1,700 arthropod species, and more than 100,000 individuals. A rainforest tree alone can have some 1,200 species of beetle, while a single hectare of rich forest canopy is projected to have 12,448 beetle species.
There are many insects and other invertebrates that would not usually be considered arboreal but exist in the rainforest canopy. For example, several species of crabs have been found hundreds of feet above the ground in tank bromeliads of neotropical forests. Similarly, earthworms and giant planarians (flatworms) are also part of the canopy system, with earthworms playing an important role in the processing of canopy soils and mulch that supports epiphytic growth. Even leeches are found in the canopy where they may surprise first-time visitors to the Asian forest canopy. Mosquitoes, too, are abundant in the canopy, though on the ground there are generally few puddles for breeding and no pronounced seasonal changes to stimulate massive mosquito-breeding frenzy. In the canopy, mosquitoes lay their eggs in the up-turned leaves of epiphytes like tank bromeliads. Therefore, you may be more likely to get mosquito bites in the canopy than on the forest floor.
Many insects like stick insects, katydids, leaf hoppers, and mantids have developed incredible behavior, body structure, and color to mimic their surroundings. These insects, which mimic dead and living leaves, half-eaten leaves, sticks, bark, bird droppings, and flower parts, avoid detection by predators and prey as they hunt and rest.
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Hyla tree frog species
Monkey frog (Phyllomedusa bicolor)
Hyla rhodopepla tree frog on leaf
Glass Frog, Costa Rica
Tree Frog, Thailand
Colorful, but known grasshopper-like insect
Black grasshopper with indigo blue eyes and yellow polkadots
Unknown insect
Giant metallic ceiba borer beetle, Euchroma gigantea, on Kapok tree
Cave Dwelling Ratsnake (Elaphe taeniura ridleyi) grabbing a bat in flight and eating it
Wild Mountain Horned Dragon (Acanthosaurus armata) on tree trunk
Varanus salvator monitor lizard
Blue-eyed lizard in Malaysian rainforest
Bright green lizard (Bronchocela cristatella?) in Java, Indonesia
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Blunt-headed tree snake (Imantodes lentiferus)
Phelsuma madagascariensis kochi
Phelsuma gecko near Maroantsetra
Emerald boa
Green Tree Monitor (Varanus prasinus)
Green Vine Snake (Oxybelis fulgidus)
Boa
Moth, Honduras
Leaf mimic insect
Monitor lizard (Varanus salvator) emerging from a tree hollow
Green-eyed gecko (Gecko stentor)
Cave Ratsnake (Elaphe taeniura ridleyi) swallowing a bat
Green vine snake in Malaysia
Brown frog on leaf in Ubud
Green Tree Python
Yellow and brown toad in Sulawesi
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Boophis frog, Masoala National Park
Boophis tree frog
Phelsuma Day Gecko on bamboo
Male Iguana
Langaha madagascariensis (male) snake
Anole lizard showing its bright orange dewlap in a territorial display
Green, teal, blue, pruple, red, and black insect in Peru
Katydid, Honduras
Praying Mantis, Honduras
Gmelin's Bronzeback snake (Dendrelaphis pictus) eating a frog
Close up headshot of the blue-eyed forest dragon of the Malaysian jungle
Gmelin's Bronzeback snake (Dendrelaphis pictus)
Green Crested Lizard (Bronchocela cristatella)
House gecko (Hemidactylus frenatus)
Gecko lizard species with black markings
Tree frog in the tropical forest of Borneo
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Review questions:
- What is the most abundant type of amphibian in the rainforest?
- What is the most diverse group of creatures in the rainforest?
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Continued: Forest floor
This article was written by Rhett A. Butler [bibliographic citation for this page] and was last updated on the most recent date listed in the column on the right side.
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WEEKLY NEWSLETTER
INTERACT
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Recent news
Vampire and bird frogs: discovering new amphibians in Southeast Asia's threatened forests
(02/06/2012) In 2009 researchers discovered 19,232 species new to science, most of these were plants and insects, but 148 were amphibians. Even as amphibians face unprecedented challenges—habitat loss, pollution, overharvesting, climate change, and a lethal disease called chytridiomycosis that has pushed a number of species to extinction—new amphibians are still being uncovered at surprising rates. One of the major hotspots for finding new amphibians is the dwindling tropical forests of Southeast Asia.
Photos of the day: satellite tagging a 12-foot saltwater crocodile
(02/06/2012) Researchers in the Malaysian state of Sabah on Borneo have successfully satellite-tagged a 3.6 meter (11.8 feet) saltwater crocodile (Crocodylus porosus) in an effort to study human-wildlife conflict with the world's largest reptile. As massive, powerful reptiles they are quite capable of injuring and killing adult humans.
Photo of the day: super-abundance of life found in Amazon park
(02/02/2012) Surveying a little-explored park in the Peruvian Amazon has paid off in dividends: researchers with the Wildlife Conservation Society (WCS) have cataloged 365 species that had not yet been recorded in Bahuaja Sonene National Park. The never-before recorded species included two bats, thirty birds, and over two hundred butterflies and moths.
Invasion!: Burmese pythons decimate mammals in the Everglades
(01/30/2012) The Everglades in southern Florida has faced myriad environmental impacts from draining for sprawl to the construction of canals, but even as the U.S. government moves slowly on an ambitious plan to restore the massive wetlands a new threat is growing: big snakes from Southeast Asia. A new paper in the Proceedings of the National Academy of Sciences (PNAS) has found evidence of a massive collapse in the native mammal population following the invasion of Burmese pythons (Python molurus bivittatus) in the ecosystem. The research comes just after the U.S. federal government has announced an importation ban on the Burmese python and three other big snakes in an effort to safeguard wildlife in the Everglades. However, the PNAS study finds that a lot of damage has already been done.
California city bans bullfrogs to safeguard native species
(01/26/2012) Santa Cruz, California has become the first city in the U.S. to ban the importation, sale, release, and possession of the American bullfrog (Rana catesbeiana). Found throughout Eastern and Central U.S., the frogs have become an invasive threat to wildlife in the western U.S. states and Canada.
More rainforest news
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