The Tuiuiu is mosly black and white: its white body is offset by a black head and neck. Between these two colors is a strip of bright red at the base of its neck. Its red and black neck is not colored by feathers; rather, these are the colors of its naked skin, which stretches to accommodate the great quantities of small animals and fish that pass down its gullet. The Tuiuiu lives in groups, but generally mates for life, creating from one to three chicks each season from late July to September. It creates large nests out of interlaced sticks in the tops of tall trees and even goes back to the same nest each season to remodel and expand it.

It’s easy to spot Tuiuiu in the Pantanal during their mating and incubation period, which corresponds to the dry season in the Pantanal. Often, they stand up in their nests, keeping a lookout or hang around in groups near small ponds and lakes. They are rather sensitive and don’t let visitors get too close, so be sure to bring a good pair of binoculars to get an up-close look.

The Boto’s shocking color comes with age. A full-grown adult is bright pink, reaches almost three meters in length, and weighs up to 200 kilos. This makes it among the largest of its species, including among ocean-going dolphins. Aside from its shocking color, the Boto looks very much like its ocean-going cousins, but with a few particularities no doubt evolved to suit its fresh-water environment. In particular, its body is more flexible and “bent” than other dolphins, giving it extra maneuverability in the intricate waterways of the Amazon. Instead of a dorsal fin, it has a pronounced ridge along its back. Another difference is that the Boto usually swims alone or in pairs, a behavior attributed to its relative lack of natural predators.

The Boto’s biggest enemy is the local fisherman. Excessive fishing of the Amazon River Basin diminishes the Boto’s food supply and makes hunting difficult. Dolphins also get caught in fishing nets and drown. In a note of karmic justice, the Boto’s hunting practices frustrate the fishing methods of the locals. The Boto herds fish into shallow waters where it captures them, whereas Fishermen depend on calm conditions and fish that are not being pursued by a Boto.

Apart from its rivalry with fishermen, the Boto has enjoyed a special relationship with indigenous groups of the Amazon, who consider it taboo to hunt or eat the animal. The Boto plays a large role in native lore and is considered a magical and powerful being, not all that different from humans. Legend has it that the Boto occasionally takes on the guise of a human and hangs around the river banks looking for young women to seduce. A bastard child is usually the result. Its reputation as a lover has given it the name boto amorador (Lover Boto) among local tribes and has made it the primary scapegoat for all unwed mothers. Women are warned against swimming near the river banks and riding alone in canoes. But the Boto can also take the form of a beautiful woman who seduces the men of the region. Any man fortunate enough to encounter such a creature will forever be protected by her when in the waters of the Amazon.

These legends no doubt have a grain of truth somewhere within them. Dolphins are known to be among the few species on the planet (along with humans) that engage in sexual activity for purposes other than reproduction (i.e., for enjoyment). And the sex organs of both the male and female Boto are also said to have a striking resemblance to human sex organs.