Just finished Archie Carr’s So Excellente a Fishe, first published in the 1960s, with a revised edition from 1982. The downtown library in Fort Lauderdale, of which I have recently become a card-carrying member, had a copy of the 1982 edition, and I read it on the planes and in the airports on my recent northern tour. Despite the dramatic advances in biologists’ toolkits in the time between this natural history and the most recent one (Spotila, 2005; Safina, 2006), there’s a freshness and a rhythm to Carr’s writing that more modern authors, with far better data at hand, simply don’t offer.
This is not really a book review, more of a “here’s some stuff I hadn’t known before I read this book”:One thing I learned about hatch-out from this book was the cooperative function of mass hatching. Inside the nest, the baby turtles don’t all scratch for the surface the instant they’re free of the egg. Instead, they wait until they reach a kind of critical mass, at which point all the nestlings scramble together for the sea. And this behavior aids the hatchlings in several ways:
- The geometry of the nest changes as baby turtles hatch out: the hatchlings take up less room than the spherical eggs with air pockets between them, affording the turtles some room to move and breathe
- Each individual turtle is both “egged on” by the actions of those around it and physically aided by those same actions: the constant poking and prodding by hatchmates stimulates movement, while the various layers of the turtle-nest “pie” help excavate the nest at far lower energetic cost than if a single hatchling were to attempt to dig out alone. Those on top dig up; those on the sides excavate sideways and undermine the top, sending sand down below, where the hatchlings there smash it down flat.
All this action helps the vast majority of hatchlings boil up out of the sand at roughly the same time. Once up on the beach, the crowd action continues to help, again in a couple of ways:
- In navigating toward the ocean, one turtle can easily steer a bum course; having a large number of nestmates helps increase the odds of steering a good course, and provides a physical encouragement to correct course–when you get beat on by dozens of bodies going the other way, you tend to orient yourself with the group, like a self-correcting market. Hmm. Bad metaphor, at least in this market climate.
- Having dozens of nestmates probably reduces the odds of predation, saturating the available predators, sacrificing a few, but saving many. Single turtles all in a row would make a nice buffet line; dozens in a swarm are harder to pick off.
Well, anyway, those are just a few of the tidbits I gleaned from this classic study of the natural history of the sea turtle. Later on, I’ll get to the updated version, Voyage of the Turtle, by Carl Safina, bought at the mall in Chicago. It’s all about leatherbacks, the most mysterious turtle left in the water, after the discovery of the nesting grounds of the Ridley (a problem that vexed Dr. Carr endlessly in The Windward Road). Although Safina undoubtedly is aware that birds are dinosaurs, his subtitle (In Pursuit of the Earth’s Last Dinosaur), while technically inaccurate, does capture the awe-inspiring sense of antiquity one feels when confronted by any of these magnificent beasts.
References:
Carr, A. 1967, 1982. So Excellente a Fishe. New York: Charles Scribner’s Sons.
Safina, C. 2006. Voyage of the Turtle: In Pursuit of the Earth’s Last Dinosaur [sic]. Macmillan.
Spotila, J. 2005. Sea Turtles: A Complete Guide to their Biology, Behavior, and Conservation. Baltimore: Johns Hopkins University Press.