It’s ironic that the so-called Father of Tragedy was killed by so comical device as a falling turtle. Aeschylus, author of the Oresteia cycle and one of the original masters of Greek theatre, was said to have died of a traumatic brain injury when an eagle mistook his bald head for a rock and dropped a turtle on it. Is that comedy, or is that tragedy? One day, you’re creating the artistic devices which will influence all of Western theatre, cinema, and literature for millenia to come; the next day, Bam! Turtle to the head.
Either way, it is an ignoble and contrived death for a playwright; too hasty, random, deus ex machina. And if the story is true, it was probably not anything even so noble as an eagle that dropped the fatal turtle, but a Lammergeier, or Bearded Vulture. Dropping turtles on rocks is a special trick peculiar to this magnificent bird, whose wingspan can reach 9 feet in diameter. But turtles are only a side dish to the Lammergeier’s main staple, which is bone marrow. If you are laying around today still digesting Thanksgiving dinner, imagine what it would be like if, instead of turkey, you were digesting pure bone.
In the Old World, in places where vast forests don’t hide the dead, vultures have evolved to eat primarily large carcasses. A water buffalo rotting in the Tanzanian sun will feed a whole flock of Gryphon vultures, whose raspy tongues will leave its bones licked clean as if preserved for mounting in a museum. But Nature abhors waste, and there is yet nutrition in a skeleton. Enter the patient Lammergeier, the vulture of vultures. Though only 15 lbs, it is large enough to pick up an 8 lb. water buffalo femur and carry it on thermal updrafts. When it is high enough, it will drop the bone on a large, flat rock — it usually has a favorite cluster of rocks, called an ossuary — hoping to shatter it and get to the marrow. It is a difficult skill to master, taking up to seven years for young birds to learn, but it is worth the practice. Marrow is an incredibly rich source of protein and nutrients, and a Lammergeier can expect to be as well-fed from the marrow in a skeleton as it would if it were sitting down to the meat from the carcass. But the Lammergeier has no special tools for extracting the marrow, it also has to eat the bone shards to which the marrow clings.
Bone is an extremely indigestible material, being essentially an organic limestone, calcium hydroxyapatite. If you were to eat large bone shards, you’d probably tear your intestinal lining before you extracted much of its nutriment. Very few animals eat bone because few animals have any reason to. Almost alone in the animal kingdom, the Osedax polychaetes, or boneworms, digest the bones of whales that have fallen into the abyss — a phenomenon rare enough to warrant its own term, “whalefall” — scraping out whatever fats they can from between the ossicles; like writhing flowers in long planting boxes, there are gardens of these in the graveyards of the deep. Hyenas will eat bone, but it doesn’t make up a significant part of their diet. Lammergeiers, on the other hand, have a diet that is 90% bone; they will even eat owl pellets, which contain the swallowed bones an owl couldn’t digest. Lammergeiers have solved the problem of bone digestibility by creating incredibly caustic gastric acid. Human gastric acid remains between pH 1 and pH 1.5, while a Lammergeier’s stomach registers around pH 0.7, making it close to pure hydrochloric acid. Add to that an extra-long intestinal tract and a lifestyle of effortless gliding, and you can see how the birds make a living out of eating bone. To get to the rarest and most succulent meat on the cow, a Lammergeier has a stomach that can dissolve almost anything.
Vultures are peaceable sorts of birds, and Lammergeiers are the most peaceable, as they rarely squabble while eating. After all, getting their food is a matter of skill, not speed. They will tussle for mates, as many animals do, but rarely fight over meals; theirs is a meditative ritual of flying, dropping, breaking. A Lammergeier might drop the same bone twenty times before it falls at just the right angle to crack it. It is hard and lonely work. But only once the Lammergeier has broken its bones — expertly, gracefully, with much concentration — is an animal truly and completely gone. This great kite of a bird is the last stop before oblivion: before it, there are still parts of you in the food web; after it, all that is left is mineral. You’re not truly gone before there’s nothing left of you to use. Nature always licks its plate clean, often right off the fine china.