Dolphins - Kidcyber

kidcyber

• Home
• About Us
• for Teachers
• For Parents
• Homeschooling
• Contact Us

• Home/
• About Us/
• for Teachers/
• For Parents/
• Homeschooling/
• Contact Us/

Dolphins

• Home/
• About Us/
• for Teachers/
• For Parents/
• Homeschooling/
• Contact Us/

• Dolphins are not fish.
• They are small whales.
• They are animals that live in the sea.
• They breathe air like we do.
• They have skin, not scales.

Dolphins are small whales. They are in the group of whales known as toothed whales.

Cetaceans (say see-tay-shuns) are mammals, which means they breathe air, give birth to live young that drink milk from their mother's body.

The dolphin has a very close relative, the porpoise (say por-puss), and the two are so similar that for a long time the words were interchangeable as though they were different names for the same animal. However, the 6 species (kinds) of porpoise have blunt heads - they do not have the beak and melon-shaped foreheads that dolphins have. Porpoises have small spade-shaped teeth.

Dolphin teeth are cone-shaped, and the top and bottom teeth interlock. They have a melon-shaped head, most have a beak, and many small pointed teeth. They have a dorsal fin, which stands up on their back.

Most dolphins live in shallower parts of oceans in warm and temperate areas of the world.

Dolphins swim about 250m below the surface of the sea, and can hold their breath for about 15-20 minutes. They use echo-location to navigate and find food. This means they make a high-pitched sound that bounces off objects around them, and then listen to the echoes, which they use to locate and identify the objects.

Dolphins are highly intelligent and playful. They are very social , and live in groups that can be as many as several hundred.

They frequently pop their heads out of the water to see their surroundings, a habit known as 'spy hop'.

Groups also swim alongside ships, using the wave created by the ship's bow (the pointy bit at the front, pronounced like bough), which is called 'bow-riding'. Scientists think is a way of conserving energy.

Diet

Dolphins eat a variety of prey such as fish, squid and crustaceans. Groups hunt together, surrounding a school of fish and taking turns to swim through the fish and catching some. They also follow fishing boats to feed on fish that may be thrown overboard or drop from the nets.

Life Cycle

Female dolphins give birth to a single calf, very rarely twins, 9-17 months after mating with a male. The length of time depends on the species.

The calf is born tail first, and as soon as the head appears, the calf is guided to the surface to breathe. It suckles its mother's milk for about 1-2 years.

There are 2 groups of dolphin: short-beaked and long-beaked. There are around 42 species, or kinds, of dolphin, including bottlenose dolphin, Risso's dolphin, false killer whale, Pacific white-sided dolphin, orca whale (the biggest dolphin), longfinned pilot whale, shortfinned pilot whale, and Irrawaddy dolphin.

Freshwater Dolphins

Most dolphins live in the oceans, but a few species, or kinds, live in fresh water. There are four species of these dolphins, called river-dolphins. As their name suggests, they live only in rivers. They all have a long, slender beaks with many teeth. They have small eyes. Their dorsal fins are less developed than those of ocean dolphins, and their bodies are thicker. They live in muddy river estuaries (where a river meets the sea) and rely on excellent echolocation (sounds that are sent out and bounce back off objects in their path) in order to find their way about.

The existing river-dolphin species are:

• the Indian river-dolphin (sometimes known as the Ganges river-dolphin),

• the Indus river-dolphin, which is almost blind.

• the Amazon river-dolphin (called boto),

• the La Plata dolphin.

All river-dolphins are threatened or endangered.

A Recent Extinction

Extinct means gone forever, there are none left. On 8th August 2007, it was officially confirmed that the Yangtze river- dolphin (baiji) was extinct after an intense six-week search failed to find even a trace of one in the whole 1,669 km of the Yangtze River. The extinction of this rare animal was suspected in 2006, but is now confirmed. The team of searchers, which included Chinese government scientists and other conservation experts, used two boats and searched the river four times, listening and looking for the dolphins. The Chinese government had intended the team to find Yangtze river-dolphins and move them to a new, protected, reserve in a lake as part of a program designed to save them. Sadly, this attempt came too late.

The Yangzte river-dolphin numbers had been dropping steadily. They were declared endangered in 1979. In 1998 only 7 were found. The last captive baiji died in 2002. The Yangtze River is so heavily polluted that it may never recover. It is a major shipping traffic area.

A New Dolphin!

In 2005, scientific tests proved that small dolphins in Australian coastal waters thought to be Irrawaddy dolphins were in fact a different, previously unknown species. They have been named the Australian snub-fin dolphin. The 1.5m animals are social, living in groups.

This species of dolphin has a very blunt, round head and a small blunt, triangular dorsal fin. They are found across Australia's northern coast from the Kimberley to the Gladstone area of Queensland, in tidal creeks where they enter the sea, in rivers and mangroves, in water less than 15m deep.

They feed on fish, squid and prawns which they catch by spitting jets of water, which is thought to confuse its prey. Their numbers are not known but they are classified as Near Threatened.

It’s a good idea to get information from more than one source!

Read about dolphins

https://www.activewild.com/facts-about-dolphins-for-kids/

https://www.sciencekids.co.nz/sciencefacts/animals/dolphin.html

Watch a video about dolphin parenting

Watch a video about dolphins, how they communicate, about echolocation, and how calves learn what they need to know.

Read the kidcyber page

Whales

If you use any part of this in your own work, acknowledge this source in your

bibliography like this:

Sydenham, Shirley. & Thomas, Ron. 2022. Dolphins [online] www.kidcyber.com.au

• Home/
• About Us/
• for Teachers/
• For Parents/
• Homeschooling/
• Contact Us/

kidcyber

Welcome to www.kidcyber.com.au, a website established in 1999 for primary students and teachers.

We provide:

Easy to understand text for student research, including material for primary school students K-6Easy to navigate formatUnits of work and lesson plans for teachers on a variety of topics in key learning areaskidcyberQuests: student webquest assignments with links to information sites for research, project ideas, evaluation'Ask a kidcyber Researcher' feature where students can request specific information about a topicAdvice to parents about helping with school homework assignments and projects

Who are we?

The writers and publishers of kidcyber are Shirley Sydenham, a primary teacher, and Ron Thomas, a primary teacher-librarian. We are authors (together, individually and with others) of numerous books for teachers and kids, published in Australia and overseas. Recent books written together include Using the Library 1, 2 & 3; Thinking Through Themes (4 titles: Air, Fire, Water, Earth); and The Perfect School Project, published by and available at Teaching Solutions.

Our Audience

Students from K to 8, their teachers and parents.Homeschool students and their parents.Teacher Librarians

Animals

Australia

Food & My Body

People & Places

Planet Earth

Space

Sports

Technology & Inventions

If you:– need more help with this topic– need information for a school project– find broken linkscontact kidcyber

© 2025 www.kidcyber.com.au We acknowledge and pay respect to the Traditional Custodians of this continent and to their Elders, past, present and emerging.

WE ARE PROUD SUPPORTERS OF•THE INDIGENOUS LITERACY FOUNDATION www.indigenousliteracyfoundation.org.au •ROOM TO READ www.roomtoread.org/ •SEVEN WOMEN www.https://sevenwomen.org/, specifically their scholarship fund that provides education opportunities for Nepalese children, in particular keeping girls in school, which offers pathways to training

DISCLAIMER: In the interest of a safe, educational online experience. kidcyber provides links to other web pages, selected and examined for their appropriateness, to provide more information about a particular topic. kidcyber has no control over the information at these sites or links made from them to others sites, which might be considered inappropriate by some people. kidcyber cannot be held responsible for inappropriate sites Note: all kidcyber topics are regularly checked, updated and added to, so keep checking out this website.

The Australian Copyright Act 1968 (the Act) allows 10% of the number of words on this website to be reproduced and/or communicated by any Australian educational institution for its educational purposes provided that the educational institution (or the body that administers it) has given a Notice to Copyright Agency under part VB of the Act. For details of the CAL licence for educational institutions contact: Copyright Agency. Level 15, 233 Castlereagh Street Sydney NSW 2000 Telephone: +612 9394 7600 Facsimile: +612 9394 7601 E-mail: [email protected]

Except as permitted under the Act (for example for the services of the Crown or in reliance on one of the fair dealing exceptions i.e. a fair dealing for the purposes of research or study) no part of this website may be reproduced, stored in a retrieval system, communicated or transmitted in any form or by any means without prior written permission. All inquiries should be made to the copyright owner at [email protected]

LIKE US ON FACEBOOK!