Studying giant tortoise flips without tipping the animals over is a delicate business
When getting back on their feet, shell shape matters for these reptiles
ROOM TO REACH An extreme shell form called a saddleback on some species of Galápagos giant tortoises raises questions about how shape matters.
Y. Chiari
It would be a memorable sight. But it would also be so wrong to tip over Galápagos giant tortoises to see how shell shape affects their efforts to leg-pump, neck-stretch and rock right-side up again.
Shell shape matters, says evolutionary biologist Ylenia Chiari, though not the way she expected. It’s taken years, plus special insights from a coauthor who more typically studies scorpions, for Chiari and her team to measure and calculate their way to that conclusion. But no endangered species have been upended in the making of the study.
“They’re amazing,” says Chiari of the dozen or so species of Chelonoidis grazing over the Galápagos Islands. Hatchlings start not quite the size of a tennis ball and after decades, depending on species and sex, “could be like — a desk,” says Chiari, of the University of South Alabama in Mobile.
Two extremes among the species’ shell shapes intrigue Chiari: high-domed mountains
