Bats plant Cashew Nut Trees. In West Africa, India and the Seychelle Islands, at least seven kinds of flying foxes and fruit bats eat the cashew fruit and discard the seed or nut which drops on the ground. One of those cashew seed-planting bats is the Straw Coloured Fruit Bat.(1)

Straw-coloured Fruit Bat (Eidolon helvum) Photograph: David Liebman, Lubee Bat Conservancy

In the New World Tropics the Jamaican Fruit Bat and the Big Fruit Bat plant Cashew Trees. The Jamaican Fruit Bat, the Long-tongued Nectar Bat and the Brown Long-nosed Bat are believed by scientists to pollinate the Cashew Tree flower.(2)

Jamaican Fruit Bat Artibeus jamaicensis

WHERE DO CASHEW NUT TREES GROW?

Cashew Nut Trees first grew in northern South America. The early explorers from Portugal took Cashew Trees to other parts of the world beginning in the mid-1500’s.(3) Now Cashew Trees grow in many parts of the world including India, Africa, Sri Lanka, China, Malaysia, Philippines, Thailand, West Indies, Pacific Islands, Australia and the United States.

DO CASHEWS HAVE ANY IMPORTANCE IN ANCIENT HISTORY?

Yes, they do. If you were a Tupi Indian living in northern Brazil in the 1500’s and you owned Cashew Trees, you were an important and powerful person. The Indians depended on the Cashew Trees for food and they also used them as a calendar. They marked the passage of time by the ripening of the cashew fruit. The trees conferred on their owners a high position within a tribe. Intertribally contention over ownership of Cashew Trees could result in war.(3)

TELL ME SOMETHING ABOUT THE NATURAL HISTORY OF THE CASHEW TREE.

The evergreen tree can be about 35 feet (3 metres)tall but it looks more like a bush because the branches sweep down to the ground.(4) Cashew Trees can live for 30 or 40 years. They produce nuts for 15 to 20 years.

Here's a surprise! The nut or seed of the Cashew Tree is on the outside of the fruit, hanging from the bottom, not on the inside buried in the flesh of the fruit.(5) It is entirely different in that respect from peaches and nectarines, apples, mangoes, oranges . . . most of the fruits we are familiar with.

Cashew Fruit and Nut

IS THE CASHEW TREE USEFUL FOR ANYTHING BESIDES PRODUCING NUTS TO EAT?

Very much so. Here are just some of its uses for human beings.(5)

• Tree timber is water resistant so it is used to build boats.
• Shipping crates
• Charcoal
• Furniture
• Sap or resin from the bark of the tree is used for indelible ink and insect repellents.
• Gum from the trunk of the tree is used for binding books.
  
  
  Wahlsberg's Epauletted Bat
  An Old World Tropics Cashew Tree planter

Inside the hard cashew nut shell there is a brown oil that is toxic and powerful and valuable. It is called “cardol”. It is used for:(5)

• Foundry resins
• Waterproof paints
• Corrosion resistant varnishes
• Insulating enamels
• Special quality lacquers
• Oil and acid proof cement and tiles
• Lubricant in magneto armatures in airplanes
• Termite proofing timber
• Manufacture of plastics, varnishes, paints, printing ink, insulating material
• Reinforcement for cars, airplanes and other vehicles
  
  

WHAT ABOUT MEDICINES?

Medicines, too. People over the centuries have found relief from hundreds of undesirable health conditions using every part of the cashew tree including:(5)

• Fruit juice
• Bark
• Leaves
• Seed oil
• Green fruit
• Tender shoots

The White-shouldered Bat, New World Tropics
A fruit eating bat, perhaps a cashew seed planter?

WHY ARE CASHEW NUTS SO EXPENSIVE?

Because so much of the work of processing the nuts has to be done by hand. The process goes like this:(6)

• The fruit falls off the tree.
  
• People pick up the fruit and twist off the nut.
  
• People put the nut in water for soaking.
  
• People lay out the nuts to be sun dried.
  
• People crack open every single nut individually. They use a machine that is powered by their hands and feet.
  
• People pick out the nut from the shell by hand.
  
• People remove the red skin from the nut with a knife.
  
• People grade the nuts into one of 22 grades.

Grading cashew nuts for size and quality

THAT’S A LOT OF WORK, BUT IT GIVES PEOPLE JOBS!

You’re right. And that’s one of the things that seed-planting bats help to do is give people work so they can earn money to raise their families and pay their bills.

People who don’t have a job in the cashew processing industries can sometimes harvest the nuts from wild trees and sell them to the processors.(6)

WHO IS THAT BOY? WHAT A GREAT LOOKING T-SHIRT. I LIKE THE RED BAT. WHAT IS HE HOLDING? IT LOOKS LIKE SOME CASHEW FRUITS.

That's Dave, age 12, and he goes to a middle school in Seattle, Washington, U.S.A. After a semester of studying about Africa, Dave and his classmates put on an open night for family and friends. Based on their studies they wrote myths and folk tales, recreated African homes and made African masks and musical instruments. Each display and report was related to African life, culture, art, music, industry and employment.

Dave's report made big points for bats! The cashew nut industry in Africa provides millions of jobs for local people. To illustrate his report Dave fashioned a cashew tree branch with hanging fruits and attached cashew nuts. You can also just make out the straw-coloured fruit bat that plants cashew trees on the container Dave is holding.

I HAPPEN TO KNOW THOSE CASHEW FRUITS ARE VERY PERISHABLE AND DON'T TRAVEL WELL. HOW DID DAVE FIND TWO FRESH CASHEW FRUITS IN THE FAR NORTHWEST OF THE USA? THAT IS A LONG WAY FROM ANY PLACE WHERE CASHEW TREES GROW.

Take another look at the cashew fruits. They are really green peppers!

GOOD MATCH! AND THE RED BAT T-SHIRT; WHERE DID DAVE GET THAT?

Take another look at the T-shirt. Dave's T-shirt is from Wales and the red "bat" is the famous red dragon of Wales.

COOL. I WANT TO THANK DAVE FOR CHOOSING THE IMPORTANT CASHEW INDUSTRY IN AFRICA AS HIS PROJECT AND FOR HELPING TO PUBLICIZE THE BENEFICIAL ACTIVITIES OF THE TREE-PLANTING BATS OF THE WORLD.

Hear, hear! I'll join in that vote of thanks.

Straw-coloured flying fox (Eiodolon helvum)

References:

(1)Fujita, M.S. 1991. Flying Fox (Chiroptera:Pteropodidae) Pollination, Seed Dispersal, and Economic Importance: A Tabular Summary of Current Knowledge, Resource Publication No. 2, Bat Conservation International

(2)New York Botanical Gardens Bat/Plant Databases http://www.nybg.org/botany/tlobova/mori/batsplants/database/dbase_main.htm

(3)Olaya, Clara Ines, Caju/Maranon/Merey/Acaiu/Cashew Nut; Americas, p.52

(4)Royal Botanic Gardens, Kew (1999). Survey of Economic Plants for Arid and SemiArid Lands (SEPASAL)database. Published on the Internet;http://www.rbgkew.org.uk/ceb/sepasal/internet/
[accessed 9 March 2006 1430 hours]

(5)Purdue University, Center for New Crops & Plants, Duke, James A., Anacardium occidentale, Handbook of Energy Crops, unpublished, 1983; http://www.hort.purdue.edu/newcrop/duke_energy/Anacardium_occidentale.html

(6)Cashew Nut Processing, Technibrief, Practical Answers to Poverty; http://www.itdg.org/docs/technical_information_service/cashew_nut_processing.pdf or Search on Google for Cashew Nut Processing and select the HTML version