A study carried out by Brazilian scientists published in the British scientific magazine PeerJ on April 19th, found that pink river dolphins use 237 different sounds to communicate. Up to now, it was thought that these animals that live in rivers in the Amazon area had fewer ways of communicating because they live in small groups.

The study was carried out with river dolphins of the Inia genus, which only appear in waters close to the fish market in the city of Mocajuba, in Pará state. It showed that these dolphins interact a lot with each other. To reach this conclusion, the study used cameras and underwater microphones that recorded the dolphins for over 20 hours and collected DNA samples from them.

The most common sounds among the 237 identified are those emitted in the presence of their offspring, which showed the communication between them and their mothers.

From this study, researchers believe that it is possible to better understand how communication has evolved through sound among cetaceans (water mammals such as whales, dolphins, and river dolphins). The study could also help understand if river dolphins are affected by sounds generated by humans, such as that of riverboats.

River dolphins and dolphins

According to scientists, sounds made by the river dolphins in the study produce longer sounds and less whistles than those emitted by dolphins (water mammals found in oceans and rivers).

Aside from that, there are signs that river dolphins use whistling to keep other animals away. Meanwhile, dolphins use it to communicate, and studies have already identified signs that dolphins’ whistles might be used to call each other by name.

Sources: BBC, G1, and PeerJ.

QUESTIONS

1) According to the text, why was it believed that pink river dolphins did not produce many sounds?

a) Because their sounds were too low

b) Because nobody had ever tried to study their sounds

c) Because it was believed that communication between them did not exist at any level

d) Because they are animals that live in small groups

2) Would you like to see a river dolphin or a dolphin close up? Explain your answer.

Ixi! Você bateu no paywall!

Ainda não é assinante? Assine agora e tenha acesso ilimitado ao conteúdo do Joca.

Assinante? Faça Login

Voltar para a home

Ou faça sua assinatura e tenha acesso a todo o conteúdo do Joca

Assine