Dario D’Emanuele stretches out on his side among black and brittle volcanic rocks. He reaches into the narrow burrow with both arms. In one hand, he holds a small flashlight that catches a glint in the eyes of the seabird watching him warily. In the other hand, he holds a homemade tool called a corco: a stick with the bowl of a spoon, bent at 90 degrees, at one end. It resembles a ladle, and with a deft movement, D’Emanuele uses it to nudge the bird aside gently, just long…