Destination content © Ross Wehner & Renée del Gaudio, used from Moon Handbooks Peru, 1st edition.
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THE ENDANGERED GIANT OTTER
River otters were once found throughout thousands of miles of Amazon waters but now have been reduced to two species found mainly in remote Amazon headwaters and out-of-the-way oxbow lakes. The larger species, the giant otter, is most commonly seen in lakes, both in the lakes in Parque Nacional Manu and around Puerto Maldonado. With a length of up to 1.8 meters (six feet) and weight of 30 kg (66 pounds), the giant otter is considerably larger than the sea otters found along the West Coast of North America.
A family consists of a pair of adults plus a few juveniles, and their home is a mud cave in an oxbow lake bank, which is marked by trampled vegetation and carefully placed boundaries of feces and urine. The otters typically maintain a few campsites, which they head to during the day to sun and fish. The giant otter has stubby feet, making it an awkward land traveler, but a powerful, flattened tail for acrobatic, fast swimming. The otters eat up to 4 kg of fish a day, which they can be seen (and heard) noisily chomping from their log perches. When the opportunity presents, they will also eat baby caiman, snakes, and young turtles. Though extremely inquisitive animals, they avoid the aquatic megapredators, including the adult black caimans and anaconda that can be up to 8 meters (26 feet). In combat, a group of otters would probably prevail over these animals, with their powerful jaws and swimming abilities. A lone otter, however, is more vulnerable.
After being raised with their family, juvenile otters eventually go off on their own, staying close at first before eventually crawling overland to homestead new, empty waters. Biologists believe that less than a third of the juvenile otters survive the experience of heading out on their own, an ingrained part of otter life that does not seem to be helping the species recover from the edge of extinction.
Because of intense hunting between the 1940s and 1970s, otter populations have plummeted to the point where they have become officially endangered. Even though it is illegal to hunt otters and sell their pelts, river otter populations continue to decline in some areas. Because they are at the top of the food chain, many biologists consider their decline to be a worrisome sign of watershed contamination from the mercury used in gold mining.
For more information, see the web page of the Giant Otter Research and Conservation Project, which was launched by the Frankfurt Zoological Society in 1990: www.giantotters.com.
PINK RIVER DOLPHINS
One of the Amazon’s most flabbergasting sights, seen only in the Iquitos area, is the hot-pink body of the pink river dolphin as its rises above the muddy waters of lakes or rivers. Sometimes these enchanting creatures even swim alongside motorboats or poke their curious eyes and long, narrow snouts out of the water.
Though they look like traditional bottlenose dolphins from the water’s surface, underwater photography reveals a bizarre shape. As if hot pink was not extravagant enough, their body has a strange S-shape, with a dorsal hump instead of a fin and a huge set of flippers. Once considered prehistoric, these unusual features are now regarded by biologists as adaptations to their specialized environment. Their unfused vertebrae, for instance, allow them to contort their bodies nearly 180 degrees in search of crustaceans and fish in the grassy waters and flooded forests of the Amazon.
Biologists have not studied the dolphin enough to understand its strange color, much of which is due to capillaries near the surface of the skin. Nor has their intelligence been measured, though their brains are 40 percent larger than humans’. Like most dolphins, they communicate through underwater whistles, chirps, and clicking noises. But unlike their oceangoing cousins, they have no known predators and thus no need to swim in large pods. Large groups of both pink and gray river dolphins can sometimes be seen, however, herding and banking fish at the mouths of rivers.
It is no wonder that the pink river dolphin occupies a special place in the mythology of Amazon tribes. Some tribes consider it a sacred animal that is credited with pushing drowning humans to shore, while others say it is an evil spirit that seduces young women and leads them to a watery death. Regardless of its exact reputation, the pink river dolphin has never been hunted by Amazon tribespeople and was as a result extremely common in the lower waterways of the Amazon up until about three decades ago.
The biggest enemy of the dolphin these days is deforestation, which has damaged the dolphin’s aquatic home, and gill nets, which ensnare and drown the dolphin. The California-based International Society for the Preservation of the Tropical Rainforest (info@isptr-pard.org, www.isptr-pard.org) has launched a major campaign on the Río Yarapa near Iquitos to protect the pink river dolphin. After a decade of working with local villages and the Peruvian police, the organization reports that the number of pink river dolphins in the river has increased over the last two decades from eight to about 30 specimens. They gladly accept donations and operate a small lodge on the Yarapa known as Dolphin Corners.
THE SIDE-NECKED TARICAYA TURTLE
Fossils indicate that earth’s first turtles could not withdraw their heads into their shells. Instead they tucked their heads to one side, as the side-necked taricaya turtle still does. Reaching a maximum of 45 cm (about a foot and half) in length, the taricaya turtle eats meat but also chomps on fruits and seeds, which it can reach during the high waters of rainy season. They are solitary nesters and lay approximately 30–50 eggs, which have been an important source of protein for Peru’s Amazon natives. Thanks to programs in Reserva Nacional Pacaya-Samiria, they have been brought back from the edge of extinction in some parts of Peru though they remain fairly common along the Madre de Dios and Manu rivers. Look for groups of this aquatic turtle, all stacked on top of each other like fallen dominos, on logs jutting from the water. They sun themselves in order to increase body temperature and probably also to eliminate the buildup of algae on their shells, or carapaces.
THE “PREHISTORIC” HOATZIN—CLAWS AND ALL
In Madre de Dios, few birds are more common and bizarre than the hoatzin, a chicken-like bird with a spiky crest that can often be seen flapping noisily around bushes at water’s edge. Hoatzins stand out from other birds because they are clumsy fliers and make a creepy grunting sound. They also eat only leaves and, like cows, have three stomachs—called crops—for digesting the organic material. The leaves ferment inside their crops, give these birds a bad odor and the local nickname of “stinky bird.” The hoatzin doesn’t mind being smelly, however, because that is its main protection from predators.
Hoatzin chicks have an even more interesting defense. The chicks are born with claws on their wings—like the flying pterodactyl. When an anaconda or other predator comes to the nest to eat the chicks, they dive into the water. When the danger is past, they use their claws to climb back into their nest. Many Amazon guides say these claws are proof that the hoatzin is a prehistoric bird that has changed little since the Mesozoic era. Recent DNA analysis, however, indicates the hoatzin is a strange member of the cuckoo family and its claws are probably a relatively recent adaptation.
CAPYBARA: MASTER OF THE GRASSES
The cuddly shape and peaceful demeanor of the capybara seems profoundly out of sync with the brutal, anaconda-eat-jaguar world of the Amazon rainforest. Troops of capybara can be seen munching on the lush grasses and aquatic vegetation at the banks of most Amazon rivers (their name in Guarani means “master of grasses”). At the first whiff of danger, these timid animals scurry into the muddy water and sink like submarines out of sight. Though they are mammals, they can hold their breath underwater for up to five minutes and can even sleep underwater, their snouts barely protruding above the surface.
The Capybara (scientific name: Hydrochaerus hydrochaeris) is the largest of the world’s nearly 1,800 rodents and looks like a cross between a guinea pig and a hippopotamus. It grows to about the size of a pig (roughly 100 pounds and four feet long) and is covered with a thin layer of reddish-brown hair. It has small ears and nose, and eyes that are perched at the top of its barrel-shaped snout for easy use while swimming. Though clumsy on land, capybaras are agile swimmers with their slightly webbed toes and feet that are longer in the front than in the back.
Capybara is a prized bush meat among Amazon natives and is an important prey for Amazon megafauna such as anaconda, jaguar, puma, ocelot, harpy eagle, and caiman. Despite all the hunting, capybara remains common in Peru’s Amazon, thanks to its rapid reproduction: females begin mating in the water a year after they are born and have between two to eight babies at a time. Both male and females live to be about 10 years old.
Certain aspects of capybara life continue to perplex biologists. For one thing, the animals have a strange bump at the end of their snout that may be a scent gland for marking territory. As rodents go, capybaras are extremely vocal. They emit a bewildering series of chatters, whistles, grunts, clicks, and purrs. When danger is present, the dominant male will bark to alert the troop, much like the marmot’s shriek.
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