Monday, December 01, 2008

Sqirrels, Bikes, and Acorns

In the last couple years, I've read a number of Internet stories about cyclists who crash because a squirrel got caught in their bicycle's spokes. Often these stories come with a set of photos that show a squirrel's body, between two spokes of a low spoke count wheel.

Some long time cyclists remark that the increase in squirrel caused crashes is a recent phenomena and some blame it on the larger space between spokes in a low spoke count wheel. The logic is that the squirrel can fit through the larger space, get stuck, and lock up the wheel; in a 32-36 spoke wheel, the squirrel would just bounce off the spokes.

This seemed like a reasonable theory to me, except that there's also a story about an opera singer (I think) that crashed due to squirrel on his hybrid bike that probably had a high spoke count wheel. The existence of this crash suggested to me that squirrels can in fact get caught in high spoke count wheels, but it didn't rule out the possibility that squirrels are more likely to get caught in low spoke count wheels.

Today, I read a news story about a smaller than normal acorn crop this year, and how it is affecting squirrel populations. Then I read that this year's squirrel population has boomed.

According to biologists, acorn crops vary each year which causes fluctuations in squirrel populations, but the effect on squirrel population lags by one year, so when oak trees make many acorns one year after making few acorns in the previous year, there are not enough squirrels to eat all the acorns, and more of the acorns grow up to be trees:

"Squirrels eat acorns," he said. "These trees live hundreds of years and they make acorns to produce new trees, not to get fat squirrels. So if they produce regular seed crops, you get a buildup of squirrel population. But if they fluctuate the crop, there are some years where they're loaded with acorns and squirrels can't eat them all, and in other years there are no seeds, and the squirrel population goes down.

So what's my point? Perhaps it's just coincidence that there has been a large squirrel population the last couple years, and low spoke count wheels have become more popular at the same time. Maybe it's the high squirrel numbers that are causing more accidents, and not the wheels themselves. If this is true, perhaps next year after squirrel populations have fallen, we will see fewer squirrel caused crashes, despite even higher numbers of low spoke count wheels on the road.

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