OTHER GROUND ANIMALS

REPTILES

The most abundant vertebrate predators of the forest floor are reptiles, namely snakes and lizards. Best known of forest snakes are the giant constrictors, Pythons of Old World and Australiasia and boas of New World, but many of these are arboreal, aquatic, or relatively small. The majority of the snakes of the forest floor are small to

Big-headed Anole, Costa Rica 2001

Panther Chamleon, Ankarana (Madagascar) 1997

medium sized, nocturnal, and mildly poisonous. They eat a range of amphibians, mammals, small birds, and insects. Very few of these species pose a threat to humans, although some are notorious for inflicting bites. The fer-de-lance viper of the New World, cobras of the Old World, and bushmaster of the New World are well known examples.

There are several notable snakes of the rainforest with strange habits or characteristics. For example, the mole viper has long fangs that protrude beyond the corners of its mouth, while the African egg-eating snake, with its detachable jaw hinge, is specially adapted to feeding exclusively on bird eggs. This snake species is equipped with lower vertebrae that have an enamel-like coating and penetrate the esophagus to act as saw like structure. Although its head about the size of human finger, the African egg-eating snake can swallow eggs larger than that of a hen. One African snake species, sometimes labeled the "two-headed snake," has a tail that resembles its head, and a head that resembles a tail. In addition, to further confuse predators, the snake moves its tail in a manner that mimics the way most snakes move their head. Thus if attacked, the tail (resembling the head) is the most likely target and the snake is much more likely to escape.

The Komodo Dragon of folklore is possibly one of the largest, more formidable beasts on earth. However, in reality, many of the "facts" about the Komodo dragon are exaggerated. First of all, the Komodo dragon is a lizard belonging to the group of 31 species of lizards known as monitors, found in the Old World. Secondly, the Komodo Dragon does not reach 30 feet (9 m) as reported by many, but the largest recorded specimen was just over 10 feet (3 m) in length-still an impressive size. The Komodo Dragon is found on a few scattered islands in Indonesia south of Celebes. With a belly full of deer they may reach 500 pounds.

Chameleons, discussed in chapter 4: The Canopy are actually most active near the ground. There are some 135 species of chameleons found in Africa, half of which are endemic to Madagascar [Malagasy chameleon pictures]. These solitary lizards are well adapted to their surroundings with their well known ability to change color, along with their large eyes which can be moved independently, and their meter-long tongue. Interestingly, chameleons often do not change color to match their surroundings, but instead to convey emotions, defend territories, and communicate with mates. At the height of the breeding season, colors are spectacular, as males try to impress females. At night, in a relaxed state, chameleons turn pale, almost white.

Another group of lizards from Madagascar are the Fringed, Leaf-tailed, or Uroplatus geckos [pictures] which are incredible camouflage artists. Some species look exactly like bark, while others resemble moss when they flatten themselves against their surroundings. When discovered, Uroplatus geckos respond by throwing mouth wide open, showing the bright orange-red interior, and erecting their tail.

Amazonian Reptiles - A Historical Account

Geckos are found worldwide and are quite famous for their abundance and loud call. Numerous species are kept widely as pets, while house geckos are found in virtually every house in the tropics where they feed on house insects.

AMPHIBIANS

Poison Arrow Frog	Poison Arrow Frog
Poison Arrow Frog	Poison Arrow Frog
Poison Arrow Frog	Poison Arrow Frog
Acid Frog	Acid Frog
Acid Frog	Acid Frog
Acid Frog	Acid Frog
Acid Frog	Painted Mantella
Golden Mantella	Tomato Frog

Amphibians are common on the forest floor, although not as abundant as those of the trees. Among the best known of rainforest amphibians are the tiny, but brilliantly colored poison dart (arrow) frogs [members of the Dendrobatidae family]. These striking but slow-moving frogs secrete powerful toxins from glands on their backs and use their color to advertise their toxic composition to potential predators. The potency of the toxin varies according to the species and rainforest dwellers have been using these skin secretions for centuries to poison the tips of their blowdarts. The most toxic frog known is yellow-gold Phyllobates terribilis, of Western Colombia, which is said to be fatal if held in the hand. Indians need only rub arrow tip across the frog's back and arrow is good for a year. Other poison arrow frogs must be roasted to extract their poison. The skin secretions of poison arrow frogs have human healthcare applications as evidenced by the story of Epipedobates tricolor and ABT-594/epidatidine.

Not all rainforest frogs are so brilliantly colored. In fact more amphibians take the opposite approach to defense: camouflage. Several species throughout the world, including the horned toad and two unrelated frogs in Brazil look like dead leaves, and when disturbed stretch out their back legs and become totally still for 30 minutes.

Amphibians are on the decline worldwide -- more than 20 are known to have gone extinct this century. Several notable species including Costa Rica's Golden toad (Bufo periglenes) and the Gastric Brooding Frog (Rheobatrachus silus) of Queensland, Australia have disappeared in recent decades. Scientists are puzzled over what is responsible for species loss among amphibians -- some speculate that environmental degradation [habitat loss, climate change, increased UV-levels from ozone depletion] has weakened populations to the point of making them more vulnerable to parasites, chytrid funges, ranavirus, and deformities. Because amphibians have highly permeable skin and spend a portion of their life in water and on land, they are sensitive to environmental change and can act as the proverbial canary in a coal mine, indicating the relative health of an ecosystem.