Big Questions: Why do baby animals have pink ears? By The Conversation, adapted by Newsela staff on 03.24.20 Word Count 706 Level 640L

Image 1. Animals in colder parts of the world have lighter skin. If a light-skinned animal has blood vessels close to the surface of their ear skin, this will make the ears look pink. Photo from Wikimedia Commons.

Question: Why do baby animals have pink ears when their bodies are a different color?

Answer: Animals have many blood vessels in their ears. Blood vessels carry blood through the body. These vessels are close to the surface of their ear skin, which is pretty thin. They make the ears look pink.

Having blood vessels close to the skin helps animals keep their body temperature just right. This is true for people, too. When we're cold, the blood vessels close to our skin tighten up. This makes it harder for blood to flow. Less blood gets close to our skin, which means less heat escapes our bodies.

When we're hot, the opposite happens. The blood vessels near our skin widen. This means more blood flows. Then more heat can escape our bodies. It helps us to cool down.

Most animals actually don't have pink ears, though. Let us explain.

This article is available at 5 reading levels at https://newsela.com. Improving Chances Of Survival

Evolution is an idea about how life has developed and changes over the years. Over time, animals adapt to their environments. These adaptions help them improve their chances of survival. A trait might be their color. It might be what they eat or how they hunt. If an animal lives long enough, its children can also have traits that help them survive. Animals without these traits might get eaten or die out.

Skin Color Changes In Different Climates

Skin color is another example of an animal trait. Animals living in hot climates often have darker skin. This includes the skin on their ears. One example is the African elephant. Its ears are quite dark. They are also the biggest ears of any animal!

Animals living in colder climates usually have lighter skin. This is true for people, too. Early humans migrated out of Africa. As they moved to colder regions, their skin color became lighter.

Why does skin color change in different climates? It is because of something called pigment. Our bodies produce pigment. It gives our skin color. The more pigment our body makes, the darker our skin. Pigment helps protect against sunburn and other skin-related health problems.

Animals living in warmer climates make a lot of pigment. They need dark skin to protect themselves from the sun's strong rays. The sun is not as strong in colder, cloudier regions. Animals there do not make as much pigment. So, their skin is lighter. Lighter skin also helps them stay warmer. It reduces heat loss. That is useful if you are in a colder climate.

Animals with pink ears can have bodies of all sorts of colors. The fennec fox, for example, has pink ears and a sandy-colored coat. The color of his body camouflages him in the desert. It lets him blend into his surroundings. That way, he stays hidden during hunting. Other animals have also adapted the color of their bodies to survive.

Ear Size

Animal ears come in many shapes and sizes. Some animals, like the fennec fox, have huge ears for their body size. Bats and a wildcat called a serval do, too. Big ears help these species hear better. They can detect more sound waves.

The naked mole-rat, meanwhile, has tiny ears. This hairless creature burrows a lot, so big ears would get in the way.

Animals with big ears can also lose a lot of body heat. Their ears might not be covered with fur or feathers. When it's cold, their body heat escapes from the skin of their ears. That's why big ears are a good idea for animals that live in hot weather, like the African elephant. It's also why animals in really cold places have quite small ears. The Arctic fox is one example.

This article is available at 5 reading levels at https://newsela.com. This article is available at 5 reading levels at https://newsela.com. Quiz

1 What would lambs' ears look like with thicker skin?

(A) the same because the fur is pink

(B) the same because the skin is pink

(C) less pink because blood would not show through

(D) less pink because bones would not show through

2 Read the paragraph below from the introduction [paragraphs 1-5].

Answer: Animals have many blood vessels in their ears. Blood vessels carry blood through the body. These vessels are close to the surface of their ear skin, which is pretty thin. They make the ears look pink.

What conclusion can the reader draw based on this paragraph?

(A) Animals have blood vessels in their ears so that they can warm up easily.

(B) Animals will have pink ears if they live in places that are very cold.

(C) Animals with pink ears are the only animals that have blood vessels in their ears.

(D) Animal ears look pink because the blood vessels can be seen through the skin.

3 Which example describes an adaptation?

(A) A giraffe grows taller.

(B) A pile of leaves decays.

(C) Baby chimps mature to adulthood.

(D) Arctic foxes grow white fur in winter.

4 Which sentence from the section “Skin Color Changes In Different Climates” explains why having a lot of pigment is important for some animals?

(A) As they moved to colder regions, their skin color became lighter.

(B) They need dark skin to protect themselves from the sun's strong rays.

(C) Animals with pink ears can have bodies of all sorts of colors.

(D) The fennec fox, for example, has pink ears and a sandy-colored coat.

5 Why are there so many different colors of human skin?

(A) because of different jobs and lifestyles

(B) because of different diets and exercise

(C) because of adaptations to different cultures

(D) because of adaptations to different climates

6 What is the overall structure of this article?

(A) cause and effect

(B) order of importance

(C) problem and solution

(D) chronological order

This article is available at 5 reading levels at https://newsela.com. 7 Which factors could cause a species' ear size to adapt?

1. climbing 2. hunting 3. shelter 4. temperature

(A) 1, 2 and 3

(B) 1, 2 and 4

(C) 1, 3 and 4

(D) 2, 3 and 4

8 Read the following paragraphs from the section “Ear Size.”

Animal ears come in many shapes and sizes. Some animals, like the fennec fox, have huge ears for their body size. Bats and a wildcat called a serval do, too. Big ears help these species hear better. They can detect more sound waves. The naked mole-rat, meanwhile, has tiny ears. This hairless creature burrows a lot, so big ears would get in the way.

Which answer choice BEST describes the structure of the paragraphs?

(A) problem and solution

(B) question and answer

(C) compare and contrast

(D) chronological order

This article is available at 5 reading levels at https://newsela.com.