Hobbies And Interests
Anatomy
Pink dolphins are named for their skin color ranging from dull pink-gray to rosy pink hues. Although the reason for their unique skin color is unknown, some theories suggest it is due to capillaries close the surface. Others suggest it is because of their diet, much like the flamingo that eats shrimp and algae and takes on a pink hue. These dolphins average 6 to 8 feet long and weigh between 185 and 355 pounds. Pink dolphins have unique adaptations for their environment like long snouts with bristle-like hairs, "fingers" on the end of flippers and the ability to turn their necks 180 degrees, all useful for feeding in muddy waters. Pink dolphins have a brain capacity 40 percent larger than a human's, and is considered the most intelligent of the river dolphin species.
Reproduction
The average lifespan of the pink dolphin is approximately 40 years in the wild, but only 4 years in captivity. As a result, no successful breeding has taken place in captivity. The actual age of sexual maturity is unknown, but the average size of sexual maturity is 5 feet for females and 7 feet for males. When copulation takes place it is belly to belly. Calves are typically born after a nine- to 12-month gestation period, and when the river is at its highest levels between May and July. The average calf at birth is 2 pounds and 30 inches long.
Social Habits
The pink dolphin is the friendliest of river dolphins, and has been known to approach humans. They have no known predators other than humans, and do not need to live in large groups or "pods" for protection. Typically, they engage in solitary feeding behaviors, but cooperatively herd fish in groups at river confluences. Pink dolphins are often found in family groups of five to eight dolphins led by a dominant male.
Habitat
The primary habitat for the pink dolphin is the Amazon River. They are also found in Orinoco basins, the upper Madeira River, and other tributaries and river systems of South America near Brazil, Bolivia, Ecuador, Venezuela, Columbia, Guyana and Peru.
Diet
Pink dolphins eat a wide variety of fish crustaceans found on river bottoms. Crabs, catfish, small river fish and even turtles make up a majority of their diet.
Threats
Only 20 years ago, the pink river dolphin was considered a viable and abundant species of river dolphin. As the Amazon River basin continues to be destroyed, however, pink river dolphins have become an endangered species. The building of hydroelectric dams, mercury from gold mining, increased river traffic, oil spills and pollutant dumping all add to habitat destruction. Sound pollution is another problem causing disorientation of their navigational systems, allowing them to get tangled up in fisherman's nets or boat propellers. These dolphins are even hunted for their eyes and teeth, due to the many legends telling of the magical powers within them.