The name “pink dolphin” generally refers to the Amazon River dolphin (aka the Boto dolphin), however the Chinese river dolphin (aka the Baiji dolphin) is also known for its pinkish skin tone.
This species gets its name from its pinkish skin tone which is present throughout the dolphin’s body; however some of these dolphins may also possess a grayish skin tone (generally younger offspring) rather than pink.
In terms of location these dolphins can be found living in the Amazon, Orinoco and Tocantins with the Chinese white dolphin being located in the Yangtze rivers.
While the Amazon River dolphin can still be seen swimming throughout their local rivers the Chinese river dolphin appears to have suffered from significant loss due to pollution, construction and aquatic transportation and is considered either extinct or severely diminished.
Physical Appearance and Characteristics
The pink dolphins are marine mammals and share many of the same physical characteristics most mammals have in common such as the need to breathe air, being warm-blooded, giving birth and providing their young with dolphin milk which is produced from the mammary gland.
In order to maintain a stable internal temperature these dolphins have a layer of blubber that keeps their vital organs insulated from external temperature changes in the water and environment.
In terms of size these dolphins appear to represent the largest of the freshwater cetacean species reaching lengths of 5 – 8 ½ ft in length (occasionally more), and weighing between 200 – 500 lbs, depending on location and sex.
Female dolphins are generally larger than their male counterparts by a slight margin and the Chinese river dolphin may have a varying size and weight advantage over the Amazon River dolphin in terms of overall size.
As stated earlier these dolphins generally have a grayish or pink skin tone and are one of the only known species to possess a pink coloring.
Both the amazon river dolphin and Chinese white dolphin are known for their slender bodies, long snouts (which helps them dig for hidden food), short triangular dorsal fin and un-fused necks (which allows them to turn their head 180 degrees).
Both dolphins also appear to have very limited eyesight and primary navigate using a well developed echolocation system that allows them to detect objects in the surrounding area.
The echolocation is so well developed that they can determine an objects size, distance, density, speed, direction and height relative to its own position in the water.
By doing this they can tell what type of food is nearby and what obstacles lay in their path.
This can be especially useful during the night or when traveling in areas where light is extremely limited.
Diet and Hunting Methods
Because these dolphins can be found living in the fresh waters of the amazon river the foods they consume are largely dependent on the types of aquatic prey that inhabit their local rivers, and since the amazon is known to consume various fish species that are rare in other parts of the world this dolphins prey may include a diet that is rich in piranha and catfish, which are fairly abundant in certain parts of the amazon.
The typical diet for these river dolphins includes small fish, crabs, shrimp, various crustaceans and small turtles.
The pink dolphin is equipped with a long beak that allows it to capture prey that may be hiding in collapsed tree bark, underwater growth vegetation’s, plants and various crevices hidden throughout the riverbanks.
To assist with grabbing their prey these dolphins possess 24 – 34 canonical shaped teeth on each side of their jaw.
They also possess an unfused neck that allows them to turn their head a full 90 degrees.
As stated earlier these dolphins suffer from bad eyesight so they primarily rely on their excellent ability to use echolocation to find potential prey and avoid collision with nearby objects.
By emitting sounds and listening to the echos that return to them the pink dolphin can detect the size, direction speed and density of the objects around it in order to determine whether its food, a wall, a predator or just a floating object.
Migration and Habitat
The Amazon River dolphin can be found in the Amazon, Orinoco and Tocantins rivers while the Chinese river dolphin can be found living in the Yangtze River.
Although the pink amazon river dolphin inhibits the local rivers of the amazon within its designated area they are known to migrate from their local rivers towards other areas of the amazon during certain times of the year.
During the drought season these dolphins tend to stay within their local river habitats as the low waters keep them separated from other groups of river dolphins.
When the rain season comes around and large parts of the amazon begin to flood the pink dolphins can be seen leaving their local habitat and traveling to other destinations where they can meet, greet and mate with other river dolphins.
This may continue for several months until the rain season ends at which point the pink dolphins swim back to their local areas before the water recedes and wait for the next rain season where they can go and explore other parts of the amazon.
In addition to being home to the pink river dolphin the amazon is also known as being one of the most bio-diverse habitats around with 1/3 of the worlds known species inhibiting the amazon and its rivers.
Note: Although we refer to the amazon as having a drought season it is a rain forest and therefore the amazon is never really dry; it rains all year-long. The drought season is simply the time of year when the least rain falls and less of the environment is covered by water.
In terms of where the Chinese white dolphin lives these river dolphins can be found primarily living in the Yangtze river, which is located in China.
Unfortunately not much can be said about the migrating patterns of the endangered/extinct Chinese river dolphin at this time.
Breeding, Reproduction and Lifespan
The average gestation period for these dolphins is estimated to be between 10 – 11 months.
After birth the female dolphin will produce a thick milk which she uses to feed her child for the first several months of birth.
In some cases the mother dolphin may nurse her child for up to 1 ½ years, although some children may stop nursing after 7 – 8 months.
These dolphins generally reach sexual maturity between ages of 4 – 8 at which point they can begin bearing offspring of their own.
While fertile female dolphins may bear a single offspring once every 2 – 3 years; twins are extremely rare.
It is estimated that these dolphins have an average lifespan of 20 – 25 years.
Current Threats
Currently the Amazon river dolphin faces threats from pollution, manmade constructions, fishing and occasional poaching.
Due to the inability of researchers and local residents being able to locate the Chinese river dolphin in recent years it is believed that this species is either extinct or extremely rare.
By the 1970’s only a few hundred Chinese river dolphins were known to be left in existence, however by 21st century it became almost impossible to locate these dolphins and no confirmed spotting’s have been recorded in the last several years.
To help prevent additional poaching some countries and locations have made it illegal to hunt these marine mammals and created certain fishing restrictions in an effort to minimize loss and hopefully allow certain populations to recover.
Conservations were also put into place to prevent unnecessary killings and to try to relocate certain dolphins to safer areas where they can live without concern of human threats, both intentional and accidental.
As with other species these dolphins also face threats from natural diseases and in rare cases getting stuck in shallow river banks or between objects in the river during extreme droughts.
In cases where a group of river dolphins may end up getting sick from natural diseases this can have significant affects on small dolphin populations that are having difficulty reproducing offspring.
While these cases are extremely rare they are worth noting as a possible cause for death beyond the realm of possible human considerations and in rare cases can have a moderate to significant consequences.