Bird poop has been a favored fertilizer for centuries—and, it turns out, is an excellent preserver of human flesh. These two factors came together in the 19th century as the global trade in guano, the excrement of seabirds (or bats), took off, leading to some unexpected travelers coming along for the ride—and raking in the cash.
Guano contains essential nutrients for plant growth and naturally accumulates near nesting areas. Its Miracle-Gro properties were prized and regulated by the Incas (the word wanu is Quechua in origin), but it wasn’t until 1802 that the European world learned of this resource through the writings of Prussian naturalist Alexander von Humboldt, who traveled extensively along the west coast of South America.
By the 1840s, Europe and the U.S. were importing guano for fertilizer. When it was discovered the poop could also make gunpowder, a veritable guano mania began. Guano was soon going for about $76 per ton, and the U.S. imported over 100,000 tons of it in 1861 [PDF]. That's about $250 million in today’s dollars.
In the race to control the world’s guano deposits and secure bird poo futures for its people, the U.S. created the Guano Islands Act in 1856, allowing any U.S. citizen to claim guano-covered islands. Control over guano resources became part of the justification for the Chincha Islands War (1864–1866) between Spain and Peru and Chile, as well as for the War of the Pacific (1879–1883), in which Chile stole Peru’s guano.
In the midst of this fervor for feces, guano miners were hard at work chipping away at the hardened mounds of poo on islands in the Pacific, Caribbean, and Atlantic. Strangely, on some of these islands, among the guano they also found mummified humans.
The most well-known guano mummy is that of Christopher Delano. On the island of Ichaboe, a teeny speck of land off Namibia, a crew of guano miners found a canvas hammock containing a human body under about 6 feet of guano, with a wooden plaque saying “Christopher Delano, 1721.” A cheery pamphlet from 1854 describes his mummified corpse and its travels: “But for the hair and teeth, which were quite perfect, [it] appeared a mass resembling stone, all the natural and component parts, of the body being changed by the process of petrifaction … [and] composed chiefly of lime and ammonia.”
In spite of the quite scientific understanding at the time of both natural and artificial mummification (thanks to early interest in ancient Egypt), even with the knowledge of the formation of adipocere, or “grave wax,” on recently interred corpses, the perception of what guano could do appears to have been wrong. Delano was not “changed into a mass of lime and ammonia.” We know now that in the short term, guano can help seal dead bodies, creating an oxygen-poor and salt-rich environment that is good for preservation. In a warm, arid climate like Namibia, the guano helped dry Delano’s body and shield it from scavengers.
Captain Wethers, who commanded the crew, brought the mummy from Ichaboe to Liverpool, where it traveled to the British Museum. From there, poor Delano went on a tour of Great Britain and Ireland, where he brought in more than $150,000—the equivalent of about $4 million today.
Upon examination of Delano, British and French scientists determined that he was European and not African, and the amount of wear on his teeth suggested he was in his mid to late 30s when he died. His right shoulder is elevated and contracted, and his open mouth revealed “a death of agony” (though it's not unusual to see a gaping jaw on a mummy). His cause of death? Likely a spear wound to his right shoulder.
The writer of the 1854 pamphlet took liberties with the sparse facts available: “About 1721, the Island of Ichaboe had been the resort of nests of Pirates…. In all human probability, the most satisfactory conjecture that can be arrived at is that the unfortunate Christopher Delano was a Spaniard, joined in some piratical enterprises, and leagued with a gang of desperadoes, from one of whom, while visiting the Island of Ichaboe, he most probably received his death wound in some bacchanalism origies [sic] or sudden quarrel.”
With this amazing manufactured backstory, Delano’s body was brought to Philadelphia and exhibited before being shipped to France by the mid-1860s. Although billed as the “only one in the world” and “the solitary known example in the Universe of its kind,” it was only a matter of time—and feverish digging—before more mummies preserved by bird poop materialized. Just a few years after Delano was discovered, the British ship Octavia also docked in Liverpool with a load of guano—and the mummies of a man, woman, and child from Peru [PDF]. Like Delano, they were eventually exhibited at the British Museum in London.
In 1868, British natural historian Francis Buckland noted that he saw yet another guano mummy in a “penny show” in Edinburgh; according to the show's handbill, the body was brought from Possession Island off the west coast of Africa by Captain Dunlop’s ship Echo. The mummy was well preserved, with an oaken board that was carved “Peter Creed, 1790.” Buckland spoke with the owner, who reportedly announced that the mummy “is as good as a pension to me,” earning him today’s equivalent of $2000 in under two weeks. The owner was aware of the Delano corpse, which at that point he claimed had disintegrated due to its travels, but mused “he ain’t no use as a scientific mummy now; the more’s the luck for me as long as my Peter Creed holds together.” (Given England’s humidity, though, it is doubtful that his Mr. Creed survived for very long.)
By the early 20th century, the guano trade had tapered off. Industrialized countries found new sources of fertilizer, and it turns out that guano was not a very good source of saltpeter for gunpowder. Many islands and atolls had been completely stripped, but the legacy remains: Many remain in U.S. possession after being claimed for their guano 150 years ago. Seven of these make up the Pacific Remote Islands Marine National Monument, the world’s largest marine reserve. As for the islands that produced Delano and Creed, these today support Cape gannets and endangered African penguins, and wildlife conservationists still often visit to monitor these populations.
While guano mummies are occasionally discovered in these areas, today new finds are largely made by archaeologists excavating prehistoric caves sites in arid locations like Nevada, New Mexico, and Durango, Mexico. Still, with the popularity of bat guano as an organic fertilizer on the rise today, it’s likely more poop-preserved mummies may yet turn up.