Zebras’ Stripes Repel Parasites, Study Says

May 8, 2014

Unlocking Word Meanings

Read the following words/expressions found in today’s article. 

1. repel /rɪˈpɛl/ (v.) – to keep or force away something unwanted
Example: Insecticides help repel mosquitoes.

2. intrigue /ɪnˈtrig/ (v.) – to draw someone’s interests or to arouse curiosity
Example: The latest discovery intrigued many scientists.

3. camouflage /ˈkæmhttp://static.sfdict.com/dictstatic/dictionary/graphics/luna/thinsp.pngəˌflɑʒ/ (n.) – a method used to be less noticeable; often by disguising as a part of nature
Example: The tigers’ stripes act as camouflage in the high grass.

4. rule out /rul aʊt/ (v.) – to no longer consider something as a possibility
Example: The scientists ruled out the disease as the lion’s cause of death.

5. conundrum /kəˈnʌnhttp://static.sfdict.com/dictstatic/dictionary/graphics/luna/thinsp.pngdrəm/ (n.) – a problem that is difficult or hard to solve
Example: The origin of striped skin in animals is a big scientific conundrum.


Read the text below.
Researchers from the University of California, Davis, (UC Davis) claim that the main purpose of zebras’ black and white stripes is to repel biting insects.

The reason why zebras have black and white stripes has long been intriguing many scientists. About 120 years ago, geologists Charles Darwin and Alfred Russel Wallace tried to solve this mystery. One of their theories is that these stripes confuse predators, thus helping zebras escape.

Another theory says the pattern serves as a camouflage to hide from enemies. Lastly, the geologists thought the stripes are for heat management and that it has a social purpose.

Researchers from UC Davis studied seven different species of zebras, horses, donkeys, and the animals’ subspecies. They recorded the thickness, location, and intensity of the stripes. In addition, they compared the stripes’ details to the animals’ geographical location, distance of predators, temperatures, and population of parasites like tsetse [TSET-see, TET-, TSEE-tsee, TEE-] flies and horse-flies.

After the observations, the researchers ruled out all the previous theories and concluded that the stripes serve as protection from blood-sucking flies.

Tim Caro, lead author of the study, said that zebras located in areas with large number of biting flies have greater stripe markings. However, Caro noted that the reason why flies avoid the striped pattern is still unknown. One possible explanation is that the insects’ compound eye makes the stripes harmful to their vision.

On another note, Caro cited that no studies yet have proven the origin of zebras’ unique color. Nonetheless, he hopes that the recent discovery will help solve other evolutionary conundrums of nature.

Viewpoint Discussion

Enjoy a discussion with your tutor.  

Discussion A

·         Do you think this study is relevant? Why or why not?
·         How do you think this study can help future studies about zebra?

Discussion B

·         Can you name other animals that use their appearance for self-defense?
·         What other issues concerning wild animals should be studied about? Kindly discuss your answer.


May 8, 2014