Math in the Great Outdoors

Anyone who's ever studied Fibonacci numbers is now expecting a long ramble about pinecones, sunflower seeds, and flower petals. Sorry, out of luck. I'm sure you can find that sort of thing elsewhere. It's only taught to every elementary school student in the US school system. Okay, maybe not quite, but the number of times it was taught to me must make up for anyone out there who hasn't seen it.
In any case, what I'm actually writing about is doing math homework in the fresh, smoggy air of southern California. Under a tree, in my case, since the lack of humidity means that it's significantly cooler in the shade than the sun (a good 5-10 degrees isn't unheard of). That turned out to be a mistake. Look what happened!

Seriously, birds! Have some respect for the calculus!
For those who are a little slow on the uptake, that yellow stuff that's circled is the dropping of a kind (cheating!) bird who must have been checking out my work from above. If a bird ever turns in calculus homework that looks suspiciously like this, make sure to call him/her on plagiarism!