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Let's learn about dolphins!
There are more than 40 species of dolphins on earth.
Some are small, and some are big.
Most live in the ocean, but some live in rivers.
The most famous kind of dolphin is the bottlenose dolphin, and that is the kind of dolphin we
are going to talk about today.
Even though they live in the water, dolphins are mammals!
That means they are warm-blooded, they feed their babies milk, and they must come to the
surface of the water to breathe air.
Dolphins breathe air through a hole on the top of their head called a blowhole.
When they go underwater, dolphins close their blowhole tight!
You may know that mammals have fur or hair, and even though they do not look very hairy,
dolphins are no exception!
Baby dolphins are born with little whiskers on their jaw which fall off soon after they
are born and never grow back, leaving them smooth and slippery, which helps them swim
quickly through the water.
Dolphins are carnivores, using their pointed teeth to catch fish that they swallow whole,
but they will also eat squid and crustaceans.
Something amazing about dolphins is the way they find their prey: echolocation!
Just like some species of bats, dolphins will make a special sound which bounces off of
objects around them.
When the sound waves return to the dolphin, the shape of the echos tell the dolphin what
shape and size the object is, as well as how far away it is and how fast it is moving.
Adult bottlenose dolphins can reach lengths of up to 13 feet or 4 meters, and weights
of up 1400 lbs or 650 kilograms, but an average dolphin only grows to about 8 feet or 2.5
meters and 660 lbs or 300 kilograms.
They can live up to about 40 years and may jump out of the water 20 feet or 6 meters
into the air!
They live in oceans all around the world, only avoiding the icy waters of the Arctic
and Antarctic.
Bottlenose dolphins are gray: dark gray on the top, and light gray on the bottom.
This type of coloring is called countershading, and helps the dolphins camouflage themselves
against predators trying to see them from above or below.
Dolphins live in groups called pods, which usually have somewhere between ten and thirty
members, but dolphin pods have been spotted with more than 1,000 dolphins together!
Dolphins are very intelligent and have a special relationship with humans.
Sometimes dolphins will help human divers who are injured by pushing them to the surface,
which is something they will do for other dolphins that are hurt.
Dolphins will also sometimes help fishermen by driving fish towards them, helping the
fishermen to catch more fish than they would alone.
Once dolphins even protected swimmers from a great white shark by swimming around them
until they could get to shore.
Dolphins kept in captivity may be trained to do tricks or important work, like locating
underwater mines.
More than half a million bottlenose dolphins swim in Earth's oceans and fortunately, they
are not endangered!
If we want to keep it that way, it is important to help protect our oceans and the creatures
that live in them.
Help conserve water, pick up litter and trash that could someday get washed into the ocean,
and be sure to only buy tuna that is caught using methods that are safe for dolphins.
I hope you enjoyed learning about dolphins today.
Goodbye till next time!