The lockdown bonus birds are back! This week I want to tell you a story about the USA and guano. But first, let’s meet a bird, the Masked Booby (Sula Dactylatra).
This is one of the more widespread Boobys, inhabiting tropical waters pretty much the world over. Their hilarious name aside, their most impressive feature is their hunting technique. To catch prey they plunge-dive into the ocean on an almost vertical trajectory sometimes from as high as 100 metres in the air. It’s quite spectacular. They hit the water like a torpedo, going up to three metres deep in search of fish and squid.
But the real reason we’re meeting this bird is to talk about their poop.
Have you ever looked at a map and seen some tiny spit of land in the middle of the Pacific Ocean and thought, huh, I wonder why the United States owns that speck of nothing? No…? Is it just me?
Well, there are many tiny specs of nothing the United States owns, and they own them all for one reason: bird poo.
You see back in the mid-1800s, the USA had a problem. Their once fertile farms were struggling. For some reason the soil could no longer support crops. The problem was that as plants grow and are harvested, they remove important nutrients like phosphorous and nitrogen from the soil, making it harder for new plants to grow. Guano, though, is pack full of those nutrients. If you sprinkle a bit on the land, it replenishes the soil and can improve crop yield by up to ten times. But where did this miracle excrement come from? Why from bird butts on tiny islands in the middle of nowhere. Birds, like the Masked Booby, had been nesting on these islands for centuries, and as a result they were more or less built-up banks of sun-baked, hardened poop — delicious.
That white rock is basically thousand-year-old solidified bird poo
The United States was enamoured with the results, and so in 1856 congress passed the delightfully named Guano Islands Act, which gave any US citizen the legal right to claim any island for the US for the purpose of establishing guano mines. And claim islands they did. At the height of the land grab they had nearly 100 islands churning out tonnes of precious precious poo. Today, many of those claims have lapsed, but there are still about ten islands scattered around the Pacific and Caribbean that the US administers, mostly as bird sanctuaries now.
We don’t use guano in agriculture anymore, we use fertiliser. But it was through the process of dropping droppings onto crops that we came to learn about phosphorus and nitrogen and how plants need them to thrive, which in turn led to the development of modern fertilisers that we now rely on to feed the world. And we’ve never had any problems with those…
Anyway, thank you, Masked Booby, thank you for all the poo.
21/09/2021
Bird of the Week 