Posted in History & Literature


In the 1790’s, an Oxford University student by the name of William Buckland pulled an unusual prank. One night, he took buckets of bat guano and spread it on the Oxford College lawn, spelling out “GUANO” with the material. For those who have never heard of guano, it is the excrement of a bird or bat. You could imagine the shock of Oxford authorities the next day at the sight of poop on their prestigious lawn.

The guano was cleaned up immediately. But after a while, a mysterious phenomenon occurred. Everyone could see “GUANO” clearly spelled out on the lawn in tall, luscious grass, rising above the surrounding grass. Even after it was freshly mowed, the letters kept growing back, thicker and faster than the other grass.

The reasoning behind this is that guano is an excellent fertiliser. Animal excrements have long been used in farming as a fertiliser, as they contain vital nutrients such as nitrogen, phosphate and potassium that plants need to grow. Bat and bird poop in particular contain large concentrations of these nutrients.

Guano had been used as a fertiliser for over a millenium in the Americas, such as by the Incans. It was known to the West by the 1700’s, but the thought of applying poop to prestigious English gardens did not sit right, therefore it was not widely used for a long time.

But by the 1800’s, many European scientists noted the potent ability of guano in transforming sterile fields into plentiful farmlands in Peru. Demand for guano rose rapidly as people caught on to how guano could drastically improve crop output and food production.

Ramon Castilla, the president of Peru, capitalised on this by exporting large quantities of guano to Europe. Peru had some of the largest deposits of high-quality guano thanks to its native seabird population, with entire mountains and islands of guano being available for mining. The massive spike in guano trade resulted in Peru’s greatest age of prosperity – known as the Guano Era. Peru used this newfound economic boom to abolish slavery, eliminate head taxes on indigeneous populations and started a public education system.

This sounds like a success story, where a developing nation enjoys dramatic growth with improved quality of life for its citizens thanks to good timing and natural resources. However, the guano story has a far darker side.

To have better access to guano deposits, wars were fought and genocide committed. Chile invaded Bolivia to seize control of Guano Islands, while the USA and Britain started colonising and annexing Pacific islands to access guano reserves. Aggressive mining of guano disrupted natural habitats of seabirds and bats, resulting in destruction of entire ecosystems dependent on guano for nutrients. In the late 1800’s, approximately 53 million seabirds lived on the Guano Islands, whereas only 4.2 million lived there by 2011. Many people were forced into slavery or exploited to decrease costs of mining guano, with miners often working in horrific conditions.

Guano dominated global economics and politics of the 19th century, but its reign ended in 1913 when German chemists Fritz Haber and Carl Bosch successfully started mass-producing ammonia using a novel chemical process (Haber-Bosch process), fixing nitrogen from the air to cheaply produce nitrogen-based fertiliser. This ended the need for guano as a source of nitrogen, while dramatically improving agriculture and food supplies around the world.

Isn’t it fascinating to see how much impact bird poop has had on world history?

Posted in Psychology & Medicine

Cobra Effect

While colonising India, the British government became concerned about venomous cobra snakes causing a public safety issue in Delhi. To remedy this situation, they decided to use the people as cheap labour by offering a bounty if anyone brought in a dead cobra. They thought this would be a cost effective method of reducing the cobra population.

The strategy was initially a success, with a huge number of cobra snakes being killed for the reward. But then, something unexpected happened. People soon caught on that it did not matter where the cobra snakes came from, as long as it was dead. Therefore, they abused this loophole by breeding cobra snakes and then killing them for even more reward. The British government found out about this enterprise eventually and decided to scrap the program.

With no reason to have so many cobra snakes, the breeders decided to release the cobras. Ultimately, Delhi’s cobra population was now larger than when the program was initiated.

This is the cobra effect. Sometimes, an idea may seem novel and efficient, but human psychology can easily turn it on its head and make a problem worse than before.

A similar, but much more macabre, phenomenon happened in Edinburgh, Scotland, in 1828. At the time, anatomy was a hot new field of research, so human cadavers were in great demand by the universities, doctors and scholars. Due to a Scottish law stating that cadavers could only come from deceased prisoners, orphans and suicide victims, there was very limited supply. Following the economic laws of supply and demand, the price of a human cadaver rose more and more. “Body snatching” became a popular crime, where people exhumed corpses from graveyards and sold them for a profit.

Two men by the names of William Burke and William Hare took things one step further. The two ran a lodging house, where a tenant passed away suddenly, while owing rent. To cover the owed amount, they stole the body before the burial and went to Edinburgh University, where they sold the body to an anatomist named Robert Knox. On hearing that bodies were in great demand and that they would be paid handsomely for any more cadavers, they hatched a sinister plan.

They realised that since their “clients” did not care about where the body came from, they could easily source them through murder. Over the course of a year, they murdered at least 16 people at their lodge and sold their corpses to Robert Knox for dissection. Their choice method of murder was to wrestle down and sit on the victim’s chest to asphyxiate them (now called “burking”), as strangling, choking or using a sharp instrument would reduce the corpse’s value due to the damage.

The pair were eventually caught and sentenced to death. Hare was eventually released, but Burke was hanged and ironically, his skeleton was preserved and exhibited at the Anatomical Museum of the Edinburgh Medical School.