The jaguar is the third-largest feline after the tiger and the lion, and the largest in the Western Hemisphere.

This spotted cat most closely resembles the leopard physically, although it is usually larger and of sturdier build and its behavioral and habitat characteristics are closer to those of the tiger. While dense rainforest is its preferred habitat, the jaguar will range across a variety of forested and open terrain. It is strongly associated with the presence of water and is notable, along with the tiger, as a feline that enjoys swimming. The jaguar is largely a solitary, opportunistic, stalk-and-ambush predator at the top of the food chain (an apex predator). It is a keystone species, playing an important role in stabilizing ecosystems and regulating the populations of the animals it hunts.

The jaguar is a near threatened species and its numbers are declining. Threats include habitat loss and fragmentation. While international trade in jaguars or their parts is prohibited, the cat is still frequently killed by humans, particularly in conflicts with ranchers and farmers in South America.

Guyana's Giant River Otter is the largest of the world's 13 otter species, (the sea otter, with its more compact body, may weigh considerably more). Giant otter males attain an overall length of 1.5 to 1.8m and a weight of between 26 and 32 kg; females generally measure 1.5 to 1.7 m in length and may weigh between 22 and 26 kg. The throat and chest are usually marked with irregular cream-coloured patches or spots; the muzzle, lips and chin are often spotted white. Long and numerous facial whiskers protrude from the muzzle, forehead and temples and are believed to be highly sensitive in order to facilitate prey location in turbid waters, when vision is impaired.

Historically giant otters ranged throughout the tropical lowland rainforests and wetlands of South America. Remnant populations exist in Guyana, Suriname, and a few other countries but is considered extinct in Argentina and Uruguay. The giant river otter is an IUCN redlisted species and is considered endangered. Accelerating habitat destruction and degradation, poaching, and unmanaged tourism are likely to reduce the remaining populations by 50% over the next 20 years (three Giant Otter generations).

Anteaters are edentate animals—they have no teeth. But their long tongues are more than sufficient to lap up the 35,000 ants and termites they swallow whole each day.

The anteater uses its sharp claws to tear an opening into an anthill and put its long snout and efficient tongue to work. But it has to eat quickly, flicking its tongue up to 160 times per minute. Ants fight back with painful stings, so an anteater may spend only a minute feasting on each mound. Anteaters never destroy a nest, preferring to return and feed again in the future.

These animals find their quarry not by sight—theirs is poor—but by smell.

The giant anteater can reach 7 feet (2.1 meters) long from the tip of its snout to the end of its tail. They are generally solitary animals. Females have a single offspring once a year, which can sometimes be seen riding on its mother's back.

Anteaters are not aggressive but they can be fierce. A cornered anteater will rear up on its hind legs, using its tail for balance, and lash out with dangerous claws. The giant anteater's claws are some four inches (ten centimeters) long, and the animal can fight off even a puma or jaguar.

This species is the largest bat (Chiroptera) in the New World and the largest carnivorous bat in the world, having a wingspan of 80 centimeters (almost 3 feet) and a body length 13-14 cm (about 5 inches).

Some alternate names for this species are the False Vampire Bat, Linnaeus's False Vampire Bat and the Spectral Vampire Bat. Confusingly, they are not related to the Old World family of large carnivorous bats that are also called false vampires.

The fur on the upper parts of the bat is normally dark brown, chestnut brown or rust-orange and quite short. The ears are very long and rounded. There is no discernible tail. The large feet are robust, with long curved claws. The muzzle is long and narrow, and the teeth are strong. The noseleaf is medium-sized and lance-shaped, resembling a horseshoe and spear with a continuous rim forming a hollow cup around the nostrils.

A formidable aerial night hunter, this large predatory species takes a huge range of relatively large vertebrate prey including amphibians, reptiles, small birds and small mammals (including other species of bats) in addition to insects such as large crickets and cicadas.

The Goliath bird-eater spider is an arachnid belonging to the tarantula group, Theraphosidae and is the second largest spider in the world by leg-span, the largest by mass.

These spiders can have a leg span of up to 30 cm (12 in) and can weigh over 170g (6 oz). They are a deep-burrowing species, found commonly in marshy or swampy areas living in burrows that they have dug or which have been abandoned by other creatures.

Females mature in 3 to 4 years and have an average life span of 15 to 25 years, while males live only 3 to 6 years. Males are sometimes eaten by their mates. Colors range from dark to light brown with faint markings on the legs. Birdeaters have hair on their bodies, abdomens, and legs.

The Goliath birdeater is fairly harmless to humans, as are most species of tarantulas. Their fangs are large enough to break human skin (0.75–1.5 inches or 1.9–3.8 cm) and carry venom with effects comparable to a wasp's sting. When threatened they rub their abdomen with their hind legs to release hairs that are a severe irritant to the skin and mucus membranes.

The pain caused by this insect's sting is greater than that of any other Hymenopteran, and is ranked as the most painful according to the Schmidt Sting Pain Index. It is said that it takes a full 24 hours for the pain to recede. A paralyzing neurotoxic peptide isolated from the venom is poneratoxin.

Fortunately, bullet ants are not aggressive except when defending themselves or their colony.

Bullet ants are used by some indigenous people in their initiation rites to manhood . The ants are first knocked out by drowning them in a natural chloroform, and then hundreds of them are woven into sleeves made out of leaves, stinger facing inward. When the ants come to, boys slip the sleeve down onto their arm. The goal of this initiation rite is to keep the sleeve on for a full ten minutes without showing any signs of pain. When finished, the boys' (now men) arms are temporarily paralyzed because of the venom, and they may shake uncontrollably for days.

The venerable Greenheart is an evergreen tree growing to 15–30 m tall with a trunk diameter of 35–60 cm. The leaves are opposite, simple, with an entire margin. The fruit is a drupe containing a single seed.

Greenheart is listed on the IUCN Red list (1996) as Vulnerable. Between 15 and 28% of the original population has been harvested to date. Harvesting as a commercial timber began in the late 18th century, but most of the harvesting has only taken place since the introduction of chainsaws in 1967.

The wood is extremely hard and strong. So hard, in fact, that it cannot be worked with standard tools. Being extremely durable in marine conditions, Greenheart is used extensively in the building of docks and in similar applications and was an early choice for fly fishing rods.

The Fram and the Endurance, the two strongest wooden ships ever constructed and made famous in the polar expeditions of Amundsen and Shackleton, were sheathed in greenheart to prevent the ships from being crushed by ice. Greenheart wood is often sought for construction projects in parts of the Caribbean where Wood ants are seen as a problem for conventional pine wood construction.

The giant South American turtle is the largest river turtle in South America. It has a broad, domed and streamlined carapace for active swimming in moderate river currents. The colour may be influenced by the algae that is attached to it, but is usually olive green to brown.

The giant South American turtle inhabits freshwater rivers with sandy banks or sandbars, which are crucial for nesting. It nests during the low water season, laying from 75 to 125 leathery eggs per clutch. Large groups of females return to the same sandy riverbanks and sandbars every year to nest in groups that are thought to decrease loss of eggs to predators. As with most turtles, the sex of the hatchlings is determined by the average temperature at which they are incubated.

Threats to this species are primarily poaching for food and oil, urban and industrial development near nesting sites, and lack of conservation education. Logging and clearing of areas surrounding rivers and damming of rivers can cause the water cycle to be drastically altered which can confuse the turtles' natural seasonal nesting cycles.

The species has very large leaves, up to 3m in diameter, that float on the water's surface on a submerged stalk, 7–8 m in length. The species was once called Victoria regia after Queen Victoria, but the name was superseded. V. amazonica is native to the shallow waters of the Amazon River basin, such as oxbow lakes and bayous. It is depicted in the Guyanese coat of arms. The flowers are white the first night they are open and become pink the second night. They are up to 40 cm in diameter, and are pollinated by beetles..

Anaconda is the common name for a large South American snake of the boa family. The anaconda - or water boa - is one of the largest and most powerful snakes in the world, and the largest in the western hemisphere. It kills its prey by constriction, or squeezing. The reptile is found in the rivers of all three Guianas as well as Brazil and Venezuela.

Primarily aquatic, they eat a wide variety of prey including fish, birds, a variety of mammals, and other reptiles. Particularly large anacondas may even consume large prey such as tapir, deer, capybara and caiman. There are many local stories and legends regarding the anaconda as a man-eater, but there is very little evidence to support any such activity.

Cannibalism among green anacondas is also known, most recorded cases involving a larger female consuming a smaller male.

Anacondas are ovoviviparous, which means that the females carry the eggs within their bodies until the babies are ready to hatch. Then, the pregnant female can give birth to anywhere from 12 to more than 80 2-foot-long baby snakes. Young anacondas are independent as soon as they are born, but will not breed for many years.

Capybara are the largest of all the I,729 species of living rodents Adult capybaras may be as long as 130 centimeters (more than four feet) and 50 centimeters (1.6 feet) tall, and weigh more than 100 pounds.

The capybara is a grazing herbivore, eating 6 to 8 pounds (2.7 to 3.6 kg) of grasses per day. Capybara are very selective feeders with four to six plant species making 75% of its diet. Capybaras are coprophagous, meaning they eat their own feces as a source of bacterial gut flora and to help digest the cellulose in the grass that forms their normal diet and extract the maximum protein from their food. They may also regurgitate food to masticate again, similar to cud-chewing by a cow.

Capybara are highly social and live in groups controlled by a dominant male. They frequently dive and may remain underwater for as long as five minutes, and can sleep with just their nose breaking the surface of the water.

They can have a life span of 8-10 years in the wild but average a life less than four years as they are "a favourite food of jaguar, puma, ocelot, eagle and caiman".The capybara is the preferred prey of the anaconda.

Harpy eagles are the largest and most powerful raptor found in the Americas and among the largest raptor species in the world.

The harpy has a wingspan of 2 meters (6.5 feet), a body length of 90-105 cm (3-3.5 feet), and weighs 10 - 20 pounds. The female can be twice as heavy as her mate.

Harpies are found in tropical lowland forests ranging from southeastern Mexico to northern Argentina and southern Brazil, with regular sightings in Guyana and Suriname. This bird prefers large expanses of uninterrupted forest, but will hunt in open areas adjacent to forest patches. They feed primarily on animals that live in the trees, like sloths, monkeys, opossums, and some reptiles and birds.

Harpy eagles build huge nests of sticks and branches in the tallest trees. Eggs take 53-58 days to hatch, with the chick fledging in 4.5 - 6 months. Juveniles stay in the parent's territory for at least a year.

The scientific name comes from the Greek word harpe referring to a bird of prey mentioned by Aristotle, Pliny, and other Greek scholars.

The Bushmaster has earned a fierce reputation, however only few human attacks have been recorded due primarily to the Bushmaster's nocturnal nature. Even if they do attack only occasionally, the Bushmaster is greatly feared by people indigenous to their jungle habitat.

Appropriately named in English, the name Bushmaster when translated from Latin means "Brings Silent Death". One of the largest and most dangerous snakes in South America, the Bushmaster is capable of multiple bite strikes, injecting large amount of venom and even the bite of a juvenile Bushmaster can be fatal. In the case of envenomation, a polyvalent Crotalidae Antivenom is recommended and contains all the necessary fractions to neutralize the venoms of all Central and South American species of Lachesis.

Education is key to understanding both the beauty and potential danger of these poisonous snakes which are best observed and appreciated from a distance. Snakes, including poisonous snakes deserve our respect - vital to a healthy ecosystem, they are very beneficial to man. Nature has given snakes the assignment of rodent population control. Snakes being broad spectrum cold-blooded carnivores, tend to take up residence where there is an abundance of prey, particularly mice and rats. Snakes help us sustain a healthy balance of life in natural ecosystems by eating a variety of prey including small rodents, birds, frogs, large insects, lizards and often, even other snakes.

The Black caiman is a a carnivorous reptile that lives along slow-moving rivers and lakes and in seasonally flooded savannas. It was hunted to near extinction primarily for its commercially valuable hide and is now listed as "conservation dependent." They are commonly seen in Guyana's Rupununi and Rewa rivers and are the subject of an intensive research project at Yupukari village.

The Black caiman is the largest predator in the Amazon basin measuring 3 to 4m (9 –12 ft) in length, with old males growing larger than 5m (15 ft). It is the third largest crocodilian in South America behind the American Crocodile and Orinoco Crocodile.

At the end of the dry season, females build a nest of soil and vegetation abd lay up to 60 eggs at the beginning of the wet season when newly-flooded marshes provide ideal habitat for the juveniles. Unguarded clutches are quickly devoured by a wide range of animals. As with other crocodilians, caimans frequently move their young in their mouths, creating a mistaken impression that they eat their young. Mothers will assist chirping, unhatched young to break out of the leathery eggs by delicately breaking the eggs between her teeth. The female only breeds once every 2 to 3 years.

Known as the pirarucu in Brazil and the paiche in Peru, this South America giant is one of the largest freshwater fish in the world. Some reach lengths of more than 10 feet (3 meters) and weigh upward of 400 pounds (180 kilograms). Large megafish like these have become rare worldwide due to heavy fishing. The arapaima is the focus of several conservation projects in the Guianas.

The arapaima is an air-breathing fish that plies the rain forest rivers, lakes and swamps. They have a wide, scaly, gray body and a tapered head. Though arapaimas can stay underwater for 10 to 20 minutes, they tend to remain near the water's surface, where they hunt and emerge often to breathe with a distinctive coughing noise. They survive mainly on fish but are known to occasionally grab birds close to the water's surface.

The Amazon's seasonal floods have become part of the arapaima's reproductive cycle. During low-water months (February to April) arapaimas construct bottom nests and females lay eggs. Young begin to hatch as rising water levels provide them with flood conditions in which to flourish. Adult males play an unusual reproductive role by incubating tens of thousands of eggs in their mouths, guarding them aggressively and moving them when necessary.