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Guano

life science Maturity 11-13 Next article →

Guano is the waste left behind by seabirds and bats.

Guano
Guano

It is a very special material because it works as a powerful fertilizer. This happens because guano contains three key nutrients: nitrogen, phosphate, and potassium. These three things are essential for helping plants grow.

Leucocarbo bougainvillii
Leucocarbo bougainvillii

Seabird guano often has more than 40% organic matter. Bat guano also has over 40% organic matter. For insect-eating bats, their guano contains tiny bits of insect shells called chitin. This chitin helps helpful fungi grow in the soil.

Microscopic Photos of Chitin
Microscopic Photos of Chitin

Guano works by providing food for plants and ecosystems. In the ocean, birds like the guanay cormorant make huge piles of waste.

These piles provide nutrients for farming. In caves, bat guano provides food for many living things. Bacteria, fungi, and small animals all rely on these nutrients to survive. If bats leave a cave, the species that eat the guano might disappear.

This shows how one small thing can support a whole world.

People have used guano for a very long time. Andean people in Peru collected it from islands for 5,000 years.

Chincha guano islands
Chincha guano islands

The Inca Empire even had strict rules about it. They valued guano so much they punished people for disturbing the birds. In 1802, an explorer named Alexander von Humboldt studied its use. He wrote about how it helped plants grow in dry places. His work made guano famous across Europe. This started a period called the Guano Age between 1802 and 1884.

During the Guano Age, many countries wanted to control it.

Guano advertisement 1884
Guano advertisement 1884

The United States passed the Guano Islands Act in 1856. This allowed Americans to claim islands that had guano. Many other nations, like Great Britain and Japan, also sought islands. In South America, the War of the Pacific happened from 1879 to 1883. This war was fought over guano and saltpetre resources. Chile won the war and gained control of many valuable islands. This helped Chile's national treasury grow by 900% by 1902.

Today, the way we use guano has changed. After 1910, scientists found a way to make nitrogen from the air. This is called the Haber–Bosch process. Because of this, people do not need as much guano for farms. However, guano is becoming popular again for organic food.

Bird Island, Walvis Bay (Namibia)
Bird Island, Walvis Bay (Namibia)

Scientists also use old guano to learn about the past. They study pollen trapped in old guano to see what plants grew long ago. It is a tiny window into history.

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🖼️ Images & Media (16)
File:Guano.jpg
Guano.jpg
File:Bird Island, Walvis Bay (Namibia).jpg
Bird Island, Walvis Bay (Namibia).jpg
File:Leucocarbo bougainvillii.jpg
Leucocarbo bougainvillii.jpg
File:Mexican free-tailed bat (8006856842).jpg
Mexican free-tailed bat (8006856842).jpg
File:Raw-Bat-Guano.jpg
Raw-Bat-Guano.jpg
File:Microscopic Photos of Chitin.jpg
Microscopic Photos of Chitin.jpg
File:Chincha_guano_islands.JPG
Chincha_guano_islands.JPG
File:Guano advertisement 1884.jpg
Guano advertisement 1884.jpg
File:GuanoPoint.jpg
GuanoPoint.jpg
File:Guano Mining in Chincha Islands Peru (1865) Moulton.jpg
Guano Mining in Chincha Islands Peru...
File:Guanay cormorant colony South Chincha Island.jpg
Guanay cormorant colony South Chincha Island.jpg
File:DefecatingSeagull.jpg
DefecatingSeagull.jpg

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