The Brazil Nut

The great tropical ecologist Adrian Forsythe tells the story of the life cycle of the Brazil Nut tree. Its future relies on three species: the Brazil nut tree, the agouti, and the jaguar.

"The agouti turns out to be a major player in the history of the Brazil nut. By burying the Brazil nuts, agoutis hold the key to the tree's survival in remote areas. The agouti is virtually the only animal that has teeth strong enough to open the thick husk and liberate the seeds so they can sprout. Ortiz was the first to fully understand the agouti's crucial role." Read more

So the 24 seeds in the Brazil nut husk are liberated and buried by the agouti, who, with its amazing memory will return to eat them — unless its memory chip is erased by a jaguar, which eats agoutis like agoutis eat Brazil nuts. So then the Brazil nuts are considered planted, and so it goes….

What a beautiful story.

Many systems in nature operate along the same lines: there are many links in the chain — if any link is cut, the chain is broken, and all species may suffer.


I heard Adrian Forsythe deliver this story during a story at the Cincinnati Zoo, for a Burrow's Conservation Series Lecture. It was there that I bought his wonderful book, Nature of the Rainforest — Costa Rica and Beyond (I already had a copy of his and Ken Miyata's fascinating Tropical Nature, which I had purchased and read just before leaving for Costa Rica for a course of study).

I want to explain the interesting mathematical symbol attached to this story: the Borromean rings.

They illustrate not only this story, but also Benjamin Franklin's famous remark: "We must all hang together, or assuredly we shall all hang separately." (at the signing of the Declaration of Independence). Like the Borromean rings, so must the Brazil nut tree, the agouti, and the jaguar hang together….

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