Amazon River Dolphin

## About

An Amazon river dolphin breaching.

The amazon river dolphin ***(Inia geoffrensis)*** or boto is a medium to large species of river dolphin that has a strikingly pink colouration giving it its name. The amazon river dolphin has a slender beak perfectly equipped for greater movement speed underwater, as it makes the animal more streamlined. Amazon river dolphins have small eyes that give the dolphin poor eyesight, along with this, they have an odd appearance when compared to other cetaceans having a humpback and a smaller than average melon. Amazon river dolphins cannot smell pollution in water leading them to often die in polluted areas. The amazon river dolphin is the smartest and largest of the five freshwater dolphin species and grows to an average length of 2.7m (9ft) and weighs 181kg (400lbs).

## Diet

Amazon river dolphins are piscivorous, meaning they eat only fish. They eat many species of freshwater fish 53 different species in fact, but mainly piranhas, tetras, croakers and catfish and the occasional crustacean.

## Conservation Status

    Amazon river dolphins are listed as endangered by the IUCN. This is because the dolphins often find themselves in highly polluted waters, and without a sense of smell they do not understand this until it is too late. The dolphins sometimes roam into high traffic areas and unfortunately, this means they get too close to boats and often get injured or even killed by the boat's propellers.

## Range and Population

    Amazon river dolphins live throughout the Amazon and Orinoco rivers of Northern South America, including the countries of Brazil, Peru, Ecuador, Colombia, Venezuela, Guyana and Bolivia. Amazon river dolphins typically inhabit rivers no matter the seasonal changes, even swimming in high water level flooded forests. Due to their nature to swim in flooded forests, amazon river dolphins have evolved an unfused neck vertebrae allowing them to bend their necks to an uncharacteristically flexible angle of 90 degrees. This in turn helps the dolphins navigate their heavyset bodies through sunken branches and trunks. Despite their large range, the exact population of mature dolphins is unknown and thought to be declining.

## Behaviour

Amazon river dolphins are social animals and travel in small groups. most commonly dolphins interact with each other during mating season in the high flooding season (June-August). During high water season, females and their young often stay in flooded forests and lakes, whilst the males live in the main rivers. The reason for why nursing mothers are often drawn to these lakes and flooded forests, is for the calve's sake. The low currant, high abundance of larvae and lack of predators like large freshwater sharks makes lakes and flooded forests the perfect place to raise a calf. Amazon river dolphins are social cetaceans that travel in small hunting parties of 2-4 individuals.

### Relationship with Humans

Amazon river dolphins, Despite being naturally shy, have been observed demonstrating curiosity towards humans and show no aggression towards humans. Cetaceans being highly intelligent animals often act kindly towards humans as they expect rewards like food. However some dolphins form long lasting emotional bonds with humans. Amazon river dolphins are considered the smartest freshwater dolphins, having a brain capacity 40% lager than humans. Both freshwater and oceanic dolphins are known to have positive interactions with humans and are also able to learn from humans.

## In Captivity

    In captivity only 3 amazon river dolphin individuals exist in zoos worldwide. The 3 zoos/marine parks that do house them are, Acuario de Valencia, Venezuela, Zoologico de Guistochoca, Peru and Duisberg zoo, Germany. Hundreds of amazon river dolphins were wild captured and traded to zoos in the US, Europe and East Asia, throughout the 1950's and 70's for their supposed exoticness. Only 20 of these animals survived and the last one died in 2002 at the Pittsburgh Zoo. In the present we have a better understanding of cetacean welfare in zoos, and the general population can agree that keeping an animal that requires plentiful space and an adequate environment in captivity is wrong and inhumane.

## Gallery

### Sources

* Boto | WWF - https://www.worldwildlife.org/species/amazon-river-dolphin
* Amazon River Dolphin Wikipedia - https://en.wikipedia.org/wiki/Amazon\_river\_dolphin
* River Dolphin Wikipedia - https://en.wikipedia.org/wiki/River\_dolphin
* IUCN Red List of Threatened Species - https://www.iucnredlist.org/species/10831/50358152