Wednesday, June 29, 2005
Turtles
I am currently doing some research (on parasites of digger bees-- whole 'nother story) in the vast almost roadless Sevilleta Wildlife reservation north of here, where no one is allowed save researchers. And I am seeing the first SMALL box turtles I have ever seen, east or west-- often. Seems the exclusion of most cars, signs reminding you to watch for turtles crossing, and maybe all- natural grazing have done them a favor. Here is a rather small-- see scale to wallet-- individual. But he is already big enough to survive coyotes-- look at those tooth scars!
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3 comments:
I agree that the many millions (billions? trillions?) of square feet of pavement we've created, and the speeding death-boxes we roll over them both exert selection pressure. Probably (almost certainly) it can be measured, even now, through museum specimens, long buried or even fossil evidence (a la "Beak of The Finch").
But the case of the turtle suggests to me that there are many other modes of response to selection pressure beside thickening shells: faster generational times (evidenced now in many commercial fisheries), dwarfism to shrink home range and dietary needs (imagine road-bordered habitats as islands), and even attendant behavioral or "psychological" changes that would make a turtle more "shy" of poured concrete? Why indeed, does the turtle cross the road?
Forgot the most obvious alternative to a thicker shell: a faster turtle! Stranger things hath Nature born.
There is also another consideration: those who stop when they see a box turtle and put him safely on the verge going in the same direction he was already heading or he will simply turn around.
Baron Bodissey always does that, even if we are late.
Sometimes, after a rain, the roads are full of turtles and one is sometimes forced to bring them all home and release them there...
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