Wednesday, October 7, 2009

Lesson Time: Of Nuts, Trees, and Squirrels

Walnuts, pecans, hazels. Yummm. Everyone has an appreciation for nuts.

What do you think about when you munch these delicious kernels? Are you filled with panic that it might all disappear? Are you a health freak obsessed with anti-oxidants? Are you proud of your North American forests for producing them?

Or are you overwhelmed by the mystery of their creation? At least for me, I was perplexed as I devoured my walnuts. I wanted to know more.

Why would a tree go through the trouble of producing a nourishment-filled nut - and then not defend it properly? The shells of walnuts, pecans, hazels, etc. are all relatively thin. Isn't that basically giving away their embryos to anything that wants to eat them?

Pecans on a tree.

I began to do a little research, and realized that the answer was right beneath my nose. Or, rather, beneath the squirrels' nose, those ubiquitous, fastidious, bushy-tailed rats that make their home amongst us. And what are they doing all the time? They are carrying nuts everywhere. Fences, trunks, and stones are all home to their embedded nuts, stashed away to be eaten in the future, when pickings are slim.

And then it came to me.

Trees want squirrels to eat their nuts.

Trees work on the principle that squirrels aren't perfect. That among the thousands of nuts that a single squirrel stashes, he will never return to them all. Perhaps he will get run over and not return to a single one, and still... The squirrel has done all the work for the tree: taken the tree's seed, excavated a nurturing nest for it, and done this a thousand times over. The squirrel is the tree's ideal gardener. Hickory, pecan, and walnut trees are all competing to make the most appetizing nut, to see who will win the squirrels services... and we all know that competition makes for a better product!

We have squirrels to thank for the nuts we love to eat. Millions of generations of squirrels have been busy shaping them, hiding and sometimes forgetting the nuts that appeal to them most. And what appeals to them? It's simple: ones that are thin-shelled, easy to open, and fit inside their mouth. It is these nuts that have the best chance of growing into trees, and in doing so, perpetuating their style.

But, leaning back and thinking about this for a moment, there lies a potential wrinkle in this philosophy. Not all nuts are easy to open! What about the massive shells of brazils and macadamias? It is impossible to open these without the aid of some serious bludgeoning.

The impenetrable brazil nut.

The answer to these massive shells lies in the countries where they hail from. Both brazils and macadamias exist in regions(South America and Australia), where there are no harsh winters. Thus there is no need for animals to cache them in order to survive during the coldest months. Instead, nuts are eaten where they found, immediately, and usually right beneath their mother tree. This destroys the reproductive potential of the tree, so, nuts such as brazils and macadamias armor themselves accordingly, to prevent such disasters from occurring.
I hope you learned something. Now read this 3 times at least. Now you are prepared with great knowledge, either to impress someone or to annoy someone just trying to eat some nuts.

As I did research on this concept, I was aided greatly by the book The Eternal Frontier: An Ecological History of North America and Its Peoples by Tim Flannery.


  1. As I was sitting observing a most fascinating cliff with but 1 pair of parrots a boy came up to me with a giant bag of nueces. Un regalo para mi!? Si senorita. Now if these mexi hills were filled con ardillas I would have gladly offered them but I greedily feasted without guilt. At my job in Seattle we get the Western Gray Squirrel hooked on Walnuts then trap them when they least expect it! mwahaha. I wll share this great knowledge with my field partner. I dont think she will be annoyed considering she dressed up as a giant squirrel for halloween with her husband dressed as the dude with the telemetry set.

  2. the great debate: rene called these nueces walnuts. but they are clearly pecans. nuez translates as walnut. dont these spanish speakers have a word for PECAN?! and, they dont even have a word for ´nuts´you have to basically name each individual nut you desire in your bag of mixed nuts. just silly.