Orinoco

Forty years ago, this magnificent monkey appeared on its way to extinction, both in its native Atlantic Coastal Forest of Brazil and in zoos as well. The wild population fell to less than 600, and in zoos, the number of deaths exceeded births. Over the next decade, improvements were made in zoo management, so that from a low of around 75, a self-sustaining population, today numbering nearly 500 world-wide, has been established. Through the reintroduction of captive-bred animals and habitat preservation, there are more than 1,000 in the wild.

Always extremely rare in captivity, this subtly beautiful toucan is common in its limited range in Colombia and Venezuela. Several arrived at the DWA through the cooperation of the Venezuelan conservation organization, FUNZPA.

Though found from Mexico to Brazil, this primitive bird has never been common in captivity. Chicks were hatched in California in the 1970s, but the species had long vanished from US collections by the time several were imported from Panama by the DWA in 2009. The large eggs are a beautiful shade of blue.

This bird has one of the smallest ranges of any toucan along the Pacific coast of Costa Rica, and a small portion of Panama. It is not rare there, but has hardly ever been seen in captivity. Through special permits from the Government of Panama, the DWA received several birds, and the world's first captive breeding took place in Dallas in 2008.

It might seem surprising that Vampire bats have the fewest number of teeth of any bat -- only 20, most of them tiny. However the incisors and canines, that dominate their jaws, are superbly suited to slice through skin, giving their owner access to the blood that is its sole food. Found from Northern Mexico to Chile, they prey on a wide variety of sleeping mammals and birds, including occasional humans (who are often attacked through their toes). They do well in captivity, and most zoo specimens are captive-bred. Their DWA diet is cow's blood.

Named for a mythical crowned serpent, basilisks are specialized iguana relatives from Central and South America. They are capable of running on their hind legs so quickly that they can cross water without sinking. The ornate crest on the head is actually an extension of the skull. This species is found from Belize to Colombia, and is also now one of the many reptiles that have become feral in Florida.

Until 2001, when the Giant huntsman spider was discovered in Laos, this enormous tarantula of the Northern South American rainforests was known as the largest spider in the world, and is still the heaviest. The legs may span one foot and they can weigh up to six ounces. While it is certainly capable of eating small birds, their more usual prey is insects, frogs, and lizards. Their venom is comparable to that of a wasp, but they are also capable of damaging human skin with their detachable irritating hairs. Females can live to be 25 years old and males only to six.

Rarely longer than five feet, this widespread South American alligator relative is the smallest species of living crocodilians. In contrast to most other crocodilians, it prefers fast moving streams with relatively cool water. Rare in collections before the 1980s, it is now bred in captivity.

When the Association of Zoos and Aquariums created Species Survival Plans in the 1980s, this critically endangered reptile was one of the first selected. That project was ended suddenly when it was discovered no US zoo actually had any. It was not until 1997, when "Juancho" and "Miranda" arrived at the DWA, through the courtesy of the Venezuelan Government, that a US breeding program for the largest New World crocodiles commenced. Since 2003, over 100 have hatched at the DWA, including 55 returned to Venezuela.

It appears there are no documented cases of piranhas killing people, but there have been several cases where they have eaten humans that had drowned. In general, these specialized relatives of the tetras are opportunistic scavengers. Of the 50 or so species found in South American Rivers, this one is the most familiar, and is popular in aquariums for its bright colors. If maintained in groups of less than four, piranhas are likely to eventually kill each other. They have been bred many times in captivity.

Though the Silver and Black arowanas of South America, and the Asian and Australian arowanas resemble each other, and share the behavior of brooding their eggs and fry in their mouths, they last shared a common ancestor around 170 million years ago, when the great Southern Continent Gondwana began to split apart. This took place in the Jurassic period, when dinosaurs still thrived. Although Asian arowanas are endangered, South American ones are abundant, and are important both to subsistence fishing and the sustainable aquarium trade.

In the 1960s, vast numbers of the tiny, brightly colored young of this species were sent to the US with shipments of tropical fish, but most did not survive. Since females may exceed 17 inches in shell length, they are not appropriate for most home aquariums. Serious private collectors and zoos have done well with them, and they have bred many times in captivity. While considered vulnerable to extinction, they remain an important resource for Native Americans in parts of their wide South American range.

A resemblance to a pile of rotting leaves serves this reptile well. When unaware small fishes swim too close, they disappear instantly -- sucked in by a powerful vacuum created when it opens its jaws. Found in quiet water across a large area of tropical South America, it usually only comes onto land to lay its eggs. It rarely swims, preferring to walk underwater, taking air at the surface through the unique proboscis in front of its tiny eyes.

Very few of the 180 or so caecilian species are easily exhibited in zoos or aquariums, as most live underground. This South American species is an exception, living in water instead. It has been bred in captivity, including the DWA, giving birth to live young. Confined to parts of the Old and Near World Tropics, caecilians compose one of the three orders of amphibians (the other two being frogs and toads, and salamanders). They are the only living amphibians with scales, but these are hidden beneath their skin.

Not related to saltwater or migratory eels, this South American fish has an elegantly minimal method of moving through water. This is mostly achieved by a parabolic wave generated through the long ventral fin. The tiny pectoral fins may steer. Most of the body is taken up by electricity generating tissue. An adult may produce a 500-watt charge. The digestive and reproductive organs are confined to a small area just behind the head. Exhibited at New York's Central Park Zoo more than a century ago, it has long been a popular aquarium display.

Also called the "Yellow-headed Amazon" this Mexican parrot has long been a popular pet, prized for its "talking" and "singing". This led to trappers stealing young birds from nests wherever they could find them. In two decades, the population fell from 700,000, in the mid-1970s, to only 7,000! This decline continues, worsened by habitat destruction. However, this species breeds well in captivity, with many hatched each year. The breeding pair at the DWA have so far reared two broods of chicks in full public view.