Fred Baes ("Bays") sent the following letter
(response sent from mail@cartalk.com).
Tom, Ray,
This is a suggestion for the guy who had the white and green identical cars. Birds were nailing the white car with their droppings, but not the green one. (I searched on "bird droppings" but couldn't find his posting.)
I suspect that birds use their own droppings--which are white--to navigate similar to the way dogs mark their territory, except birds use vision instead of smell. For years scientists have been puzzling over bird navigation invoking the position of the sun, earth's magnetic field, crystals in their brain, etc., and yet all the while the answer has been right there in front of them on their windshields. Birds obviously use "lines" of white bird droppings to chart their excursions, like vacationers use a yellow highlighter on their road maps. In essence, these birds think that this guy's white car is just a popular sign post on one of their favorite routes.
To test this theory, the guy could perform a little experiment: First, he should use threads or light pencil marks to grid off the roof of each car. Every day for a few weeks, he should record the number of hits in each grid cell on the white and green cars, washing each car after each count. After a few weeks, he can compute a new statistic, the "Bs" (B sub s for "blemish statistic") in hits/in./day. If both cars have similar Bs’s, then this guy is just imagining things, and was wasting your valuable air time with his "problem." If, however (as we all suspect), there is a significant intercar difference in Bs’s, then we have the beginnings of a viable theory (and a good reason to repaint both cars green).
Next, the guy should paint half of the roof of each car white and half green in such a way that when he parks them side by side the white and green areas match up. Again he records the number of hits for a few weeks. If the birds are indeed nailing what they see as their white target area, then both cars will have similar intercar Bs’s, BUT significantly different intracar Bs’s, with higher Bs values in the white than in the green areas of each car. At this point he could go on with further paint configurations to refine this theory (and test such corollaries as whether the Bs factor is inversely proportional to the number of days since the car was last waxed), but I believe that the theory is basically valid at this point, and he should submit these findings to some scientific journal so that he can secure funding for a new line of scientific reaseach.
The question is not whether birds use their droppings for navigation (that much seems obvious now), but *how* do they do it with such accuracy from such great heights with virtually no guidance system built into their payloads. We were all impressed by the smart bombs used in the Gulf War, but our efforts pale in comparison to the eye-sphincter coordination of the average blue jay. I'm convinced there is a vast, unexplored area of biological science waiting to be discovered. Applications to aviation, communications, and men's toilet manners are obvious. Your caller may be our next Isaac Newton, Albert Einstein or John Crapper.
I look forward to the day when future generations truly appreciate what the little winged dinosaur taught us, and smile with pride when their newly waxed car is blessed with the "little white gift of knowledge" from above.
