Pink Dolphins: Facts and Information

The Amazon river dolphin, pink dolphin or Boto is a freshwater dolphin. It inhabits South America, mainly in the Amazon river, but also in the Orinoco basin and Madeira river.

So, what actually is a Pink Dolphin?

Pink dolphins (Inia geoffrensis) are a species of Toothed whales classified in the family Iniidae and it contains three sub-species: Amazon river dolphin (I. g. geoffrensis), Bolivian river dolphin (I. g. boliviensis) and Orinoco river dolphin (I. g. humboldtiana). They seem to have some relationship with their South Asian counterparts, the Ganges river dolphin (P. g. gangetica), predominant in India, and Indus river dolphin (P. g. minor), predominant in Pakistan. The pink dolphin is the biggest of all river dolphins.

Pink dolphin facts: DIstribution in South America
Distribution on Pink Dolphin sub-species in South America

How does a Pink Dolphin look? Can you show me one?

With the adult males reaching an average lenght of 2.3 metres (7.6 ft) and an average weight of 150 kilograms (340 lb), and the females reaching a length and weight of 2 metres (6.6 ft) and average 100 kilograms (220 lb), they will not pass unseen by your side if you are navigating in their habitat. In contrast with other cetaceans, in this case, the male is bigger than the female.

Amazon Pink River Dolphin - Boto - Inia geoffrensis (Pink Dolphins)
Amazon Pink River Dolphin – Boto – Inia geoffrensis

Their cervical vertebrae are not fused, allowing the head to turn 90 degrees to each side. This, in conjunction with large pectoral fins, gives them very good maneuverability to swim through the flooded forest searching for their prey. You can see the way they swim and move in this video put up by National Geographic

In his head we found quite a few interesting things, so for the ones of you digging this article for your homework, keep reading!

They have small eyes, but good eyesight, in and out of the water. Between 25-28 pairs of teeth to each side of both jaws helps them capture fish, tortoises or crabs. It is curious tho, that they are the only toothed whales to have different types of teeth in their jaw. And finally, the melon on their heads, which they can modify by muscular control for using it as a Biosonar (or Animal echolocator)

Are they really Pink?

Depends. The color of their bodies varies with age. Young dolphins have a dark gray color, which in adolescence transforms into light gray. Adults can display a range of colors from light gray to pink (varying from solid to mottled) and even brownish.

It is not entirely clear why they have this color but one of the strongest hypothesis says it’s due to the repeated abrasion of the skin surface. Some observations correlate with this theory, for example, that males tend to be pinker than females (they fight more between them, displaying intra-species aggression). Another hypothesis, like the one of Tim Caro, mammal coloration expert from the University of California at Davis, says that this coloration could be to match the particulate red mud that follows heavy rains in some rivers.

All in all, no one knows for sure why.

Pink dolphin facts they exhibit different patterns and colors
This Amazon river dolphin exhibits a mottled pattern

What do Pink Dolphins eat?

Basically pink dolphins eat almost anything small that swims. They eat around 50 species of Amazon fishes, including piranhas. Turtles and crabs are also on the daily diet which consist of around 2.5% of its body weight every day.

Pink dolphins have a powerful jaw. The front row of teeth helps to puncture and to hold fishes (or other preys). The back row is for crushing and smashing.

After they catch their food pink dolphins swallow their food without chewing. All indigestible parts (like bones or spines) are regurgitated after.

Pink dolphin facts: They eat fishes, turtles and crabs
Pink dolphin looking for its dinner: Fishes, turtles or crabs.

Are Pink Dolphins smart?

We might have heard that dolphins are very smart animals, but what kind of intelligence do they have? The answer is Cetacean intelligence. They are aware of themselves and their different body parts, are able to experience basic emotions, engage themselves in some degree of abstract thought and understand the structure of their environment. They learn by observing and even mimicking, solve problems and choose their own actions, even remembering their own recent behavior.

When interacting with humans, they appear to recognize the difference between children and adults and tend to be more gentle and patient with childs. Some researchers suggest that dolphins are “non-human persons” who qualify for moral understanding as individuals.

There are no specific studies related to Pink dolphins and their intelligence, but being part of the same family we can suppose that they share most of their cognitive system.

For more in-depth information about the brain power of dolphins (and whales) click here

Amazon river dolphin facts: They have Cetacean intelligence
Pink dolphins are intelligent. Some researchers suggest they have moral understanding and qualify for “non human persons”.

Are Pink Dolphins threatened or endangered now?

Yes, they are threatened by many factors such as the contamination of the river (with mercury, for example, by the ilegal mining operations) and the increased deforestation of the Amazon jungle that affects many different ecosystems changing the migration patterns of some fish species that they eat.

But the main threat to them is the hunting and deliberate killing along with their incidental capture in fishing gears. A big part of the income of riverside families that live in the Amazon is the fishing activity, and dolphins are prone to damage fishing equipment when they get entangled in it or when they want to eat the fish from the nets. They are also used in the Catfish or Piracatinga, (Calophysus macropterus) fishery as bait, and the increasing demand for the piracatinga has created a market for distribution of dolphin carcasses.

Some efforts in favor of their protection are being made. Precautionary measures are one of those efforts, through good fishing practices taken together by fisheries managers and fishermen to start developing multiple-species management and ensure sustainable practices. Other measure is law enforcment, as the one put by IBAMA that prohibits killing the Amazon river dolphin (but fails to compensate the fishermen for the damage done to their equipment and catch), or the one made in year 2012 by the President of Bolivia, Evo Morales putting up a law that bans fishing freshwater pink dolphins and declares the species a National Treasure.

Pink dolphins: amazon river dolphin photo
Hello friend. I am mister pink dolphin, a national treasure.

And what about their Conservation Status?

The species is listed in Appendix II of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). It means that pink dolphins (along with other 21.000 species) are not necessarily threatened with extinction, but may become so unless strict regulation is enforced in order to protect the survival of the species in the wild. It is also listed in Appendix II of CMS meaning that they would significantly benefit from international co-operation regarding their conservation.

The Conservation Status is a classification system that shows if a species still exists or how likely it is to become extinct in the near future.

Pink dolphin information: Conservation status by IUCN
Conservation Status ranking system by the IUCN

The Pink dolphin is classified as Threatened (between Endangered and Vulnerable, due to lack of actual data)

Pink dolphin conservation status vulnerable
Vulnerable means a high risk of extinction in the wild
Pink dolphin conservation status endangered
Endangered means a very high risk of extinction in the wild

All in all, the current situation for the Pink Dolphin is worrying, with a high to very-high risk of extinction, more coordinated efforts are still needed for their preservation.

Wanna see some Pink Dolphins?

Buckle up and prepare for Adventure!


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Photo attributions:
(1) Cetacea range map Amazon River Dolphin by Pcb21 and Vardion / CC BY-SA
(2) Unknown/Pending attribution
(3) Amazonas-Flussdelfin Orinoko3 by Oceancetaceen / CC BY-SA
(4) Pucate_2015 07 27_0586 by Harvey Barrison / CC BY-SA
(5) Boto vermelho by lubasi via VisualHunt / CC BY-SA
(6) Inia geoffrensis by Joachim S. Müller via Visual hunt / CC BY-NC-SA
(7) Conservation Status Ranking by Peter Halasz (Pengo) / CC BY

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