Humans can’t breathe underwater. Water contains dissolved oxygen, but our lungs are not able to absorb oxygen out of water.
Warm-blooded sea mammals like dolphins and whales also have lungs. However, dolphins and whales have the adaptation of huge lungs that allow them to hold their breath underwater for 20 minutes. Another breathing adaptation of dolphins and whales is
a blowhole on top of their heads. A blowhole is like a nostril that can open and close to prevent water entering the lungs. When dolphins and whales swim to the surface for air, their blowholes open to breathe.
Most fish don’t have lungs. Instead, fish have a structure called gills. Gills are flaps on both sides of a fish’s head. Gills are an adaptation that allow fish to get oxygen into their bodies. Fish take in water through their open mouths. Water moves
into their mouths and out through their gill flaps. As water moves through the gills, oxygen moves from the water into tiny blood vessels in the gills. Some fish, like certain sharks, must continually swim through the water in order to breathe.
Watch More
How to Breathe Underwater... Or Not.
Sharks use gills to breathe. Watch this video to learn more about shark breathing.
Watch this video to learn more about dolphin breathing adaptations.
Seals are mammals with lungs and noses. What adaptations allow seals to stay underwater for long periods of time without breathing?
Lungfish have a very interesting breathing adaptation. They have gills to breathe underwater, but they also have lungs to breathe in air. Watch this video to learn more about lungfish.
Figure B.1.2.4 – Giant tortoises can weigh up to 400 kg.
Figure B.1.2.5 – The blue-footed booby lives in the Galapagos Islands.
Galapagos Island Animal Adaptations
The Galapagos Islands are located in the Pacific
Ocean, off the west coast of South America. Because these islands are very isolated, they are home to many unique organisms with interesting adaptations.
Giant tortoises on the Galapagos Islands have different shell shapes depending on their environment. Tortoises that live in dry areas have saddle-shaped shells. A saddle shell has wide openings so a tortoise can stretch its long neck and leg to reach
high leaves on trees and bushes. Tortoises that live in wet areas have dome shaped shells. Wet environments have a lot of vegetation on the ground. Dome-shelled tortoises have shorter necks and smaller shell openings, because they don’t need to stretch
up for food.
In the 1800’s, the biologist Charles Darwin observed finch birds on the Galapagos Islands. Galapagos finches have different beaks, which are adapted to different food sources. Warbler finches have long thin beaks that can spear insects for food. Ground
finches have short strong beaks to eat and crush seeds on the ground.
Figure B.1.2.6 – Ground finches eat seeds.
Figure B.1.2.7 – Warbler finches eat insects.
Watch More
Awesome Animal Adaptations
Watch this video to learn more about giant Galapagos tortoise adaptations.
Birds around the world have different adaptations to help them catch food. Watch this video to learn more about bird adaptations.
Try It!
Bird Beaks Simulation Try this experiment to simulate how a bird’s beak shape affects its ability to gather food.;
Materials:
Clothespin
Tweezers
Spoon
Glass
Water
Dry rice
Dry popcorn kernels
Glass marbles
Instructions:
Note: When using a “beak”, hold the beak with one hand. Don’t use your other hand to help put “food” in the beak.
Use each of the three “beaks” (clothespin, tweezers, spoon) to try to pick up the popcorn kernels. Record your observations of using each beak in the table below.
Spread some rice on a flat surface.
Use each of the three “beaks” to try to pick up the rice. Record your observations of using each beak in the table below.
Place several marbles in a glass of water.
Use each of the three “beaks” to try to pick up the marbles. Record your observations of using each beak in the table below.

Questions:
Think about the following questions very carefully. Then, type or write your answers. After you have your answers, click the questions for feedback.
The clothespin was best for picking up popcorn kernels. The clothespin had a wide, flat surface that was the right size picking up and holding onto the round popcorn kernels.
The tweezers were best for picking up tiny pieces of rice. The long thin tweezers had good precision to pick up and hold onto small individual pieces of rice.
A pelican’s beak has a round scooped shape, which allows it to scoop up water containing fish. A pelican’s beak is similar to the spoon beak.
Figure B.1.2.8 – Ostriches are flightless birds native to Africa.
Figure B.1.2.9 – Kiwis are flightless birds native to New Zealand.
Figure B.1.2.10 – Cassowaries are flightless birds native to Australia and Indonesia.
Flightless Birds
Penguins are just one type of flightless bird. Other large and small flightless birds live around the world. Flightless birds have special adaptations that help them escape from
predators.
The ostrich is a large flightless bird, native to Africa. Ostriches can grow up to 2.7 metres, or 9 feet tall. That’s taller than an adult human! Lions, leopards, and hyenas prey
on ostriches. To escape these predators, ostriches have the adaptation of strong running legs. Ostriches can run long distances at speeds up to 70 km/h!
There are a few flightless birds very similar to ostriches. Rheas live in South America and emus are found in Australia.
Another more colourful flightless bird is the cassowary. Cassowaries live in Indonesia and northern Australia. Cassowaries are able to run fast, swim, and jump up to two metres in the air. They have a very sharp toe claw to defend against predators.
The country of New Zealand has more flightless birds
than any other country in the world. There are no natural bird predators in New Zealand, so flightless birds were able to thrive until humans discovered the island country. The Indigenous Maori people over-hunted the large flightless
moa bird, which is now extinct. Europeans introduced animals like cats, stoats, and possums into New Zealand. Flightless birds cannot escape these animals and are killed by them. Species
like the kiwi have become endangered as a result of introduced predators.
Watch More
Birds That Don't Fly
 Watch
this video to learn more about the adaptations of ostriches.
Watch these videos to learn more about why kiwi birds are endangered by introduced predators.
The cassowary bird can be dangerous to humans. Watch this video to learn more about cassowary adaptations.
Make sure you have understood everything in this lesson. Use the Self-Check below, and the Self-Check & Lesson Review Tips to guide your learning.
Unit B Lesson 2 Self-Check
Instructions
Complete the following 6 steps.
Don't skip steps – if you do them in order, you will confirm your
understanding of this lesson and create a study bank for the future.
ANSWER all the questions on the downloaded quiz in the spaces provided. Think carefully before typing your answers. Review this lesson if you need to. Save your quiz when you are done.
COMPARE your answers with the suggested "Self-Check Quiz Answers" below. WAIT! You didn't skip step 2, did you? It's very important to carefully write out your own answers before checking the suggested answers.
REVISE your quiz answers if you need to. If you answered all the questions correctly, you can skip this step. Revise means to change, fix, and add extra notes if you need to. This quiz is NOT FOR MARKS, so it is perfectly OK to correct
any mistakes you made. This will make your self-check quiz an excellent study tool you can use later.
SAVE your quiz to a folder on your computer, or to your Private Files. That way you will know where it is for later studying.
CHECK with your teacher if you need to. If after completing all these steps you are still not sure about the questions or your answers, you should ask for more feedback from your teacher. To do this, post in the Course Questions Forum,
or send your teacher an email. In either case, attach your completed quiz and ask; "Can you look at this quiz and give me some feedback please?" They will be happy to help you!
Be a Self-Check
Superhero!
Self-Check Quiz Answers
Click each of the suggested answers below, and carefully compare your answers to the suggested answers.
If you have not done the quiz yet – STOP – and go back to step 1 above. Do not look at the answers without first trying the questions.
Horses eat plants like grass and hay. Flat teeth help horses to chew and grind plants into smaller pieces. Lions eat other animals. Sharp teeth help lions to tear meat into smaller pieces.
A hummingbird’s beak is long and narrow. A long and narrow beak is good for reaching into flowers. The long and narrow beak also acts like sharp tweezers, to pick up small insects.
Webbed feet are an adaptation that help animals move in water. Webbed feet provide more surface area for animals to paddle and push themselves forward while swimming.
Male peacocks have brightly coloured feathers, which attract female peacocks towards them, to mate and reproduce. Female peacocks have brown feathers which allow them to blend into their surroundings, so the bird and its eggs are not detected
by predators.
Whiskers have the function of helping animals sense their surroundings, as they are moving. Whiskers allow animals to sense objects around them, including predators and prey.
Reading and Materials for This Lesson
