Guano

Many cave ecosystems are wholly dependent on bats to provide nutrients via their guano which supports bacteria, fungi, invertebrates, and vertebrates.

Seabird guano is the fecal excrement from marine birds and has an organic matter content greater than 40%, and is a source of nitrogen (N) and available phosphate (P2O5).

[2] Unlike most mammals, birds do not excrete urea, but uric acid, so that the amount of nitrogen per volume is much higher than in other animal excrement.

The word "guano" originates from the Andean indigenous language Quechua, where it refers to any form of dung used as an agricultural fertilizer.

[7] Spanish colonial documents suggest that the rulers of the Inca Empire greatly valued guano, restricted access to it, and punished any disturbance of the birds with death.

[11] In November 1802, Prussian geographer and explorer Alexander von Humboldt first encountered guano and began investigating its fertilizing properties at Callao in Peru, and his subsequent writings on this topic made the subject well known in Europe.

[12] Cornish chemist Humphry Davy delivered a series of lectures which he compiled into an 1813 bestselling book about the role of nitrogenous manure as a fertilizer, Elements of Agricultural Chemistry.

[13] Though Europe had marine seabird colonies and thus, guano, it was of poorer quality because its potency was leached by high levels of rainfall and humidity.

[17] This export of guano from Peru to Europe has been suggested as the vehicle that brought a virulent strain of potato blight from the Andean highlands that began the Great Famine of Ireland.

In defending the workers, lawyer Everett J. Waring argued that the men could not be tried by U.S. law because the guano islands were not legally part of the country.

[25] In 1913, a factory in Germany began the first large-scale synthesis of ammonia using German chemist Fritz Haber's catalytic process.

The scaling of this energy-intensive process meant that farmers could cease practices such as crop rotation with nitrogen-fixing legumes or the application of naturally derived fertilizers such as guano.

[29] During the American Civil War (1861–1865), the Union's blockade of the southern Confederate States of America meant that the Confederacy resorted to mining guano from caves to produce saltpetre.

[36] Stable isotope analysis of bat guano was also used to support that the climate of the Grand Canyon was cooler and wetter during the Pleistocene epoch than it is now in the Holocene.

[37] Mining seabird guano from Peruvian islands has remained largely the same since the industry began, relying on manual labor.

In 1906, American zoologist Robert Ervin Coker was hired by the Peruvian government to create management plans for its marine species, including the seabirds.

[41] In 1913, Scottish ornithologist Henry Ogg Forbes authored a report on behalf of the Peruvian Corporation focusing on how human actions harmed the birds and subsequent guano production.

[17] Chinese laborers agreed to work for eight years in exchange for passage from China, though many were misled that they were headed to California's gold mines.

[45] On Navassa Island, the guano mining company switched from white convicts to largely black laborers after the American Civil War.

Black laborers from Baltimore claimed that they were misled into signing contracts with stories of mostly fruit-picking, not guano mining, and "access to beautiful women".

[50] The Centers for Disease Control and Prevention recommends that the immunocompromised avoid exploring caves or old buildings, cleaning chicken coops, or disturbing soil where guano is present.

[56] As early as in the 18th century there are reports of travellers complaining about the unhealthy air of Arica and Iquique resulting from abundant bird spilling.

The intertidal zone is inundated by the guano's nutrients, causing algae to grow more rapidly and coalesce into algal mats.

[62] Invertebrates inhabit guano piles, including fly larvae, nematodes, springtails, beetles, mites, pseudoscorpions, thrips, silverfish, moths, harvestmen, spiders, isopods, millipedes, centipedes, and barklice.

The presence of high densities of bats in a cave is predicted to cause the erosion of 1 metre (3 ft) of rock over 30,000 years.

In his 1845 poem "Guanosong", German author Joseph Victor von Scheffel used a humorous verse to take a position in the popular polemic against Hegel's Naturphilosophie.

[67] The poem ends, however, with the blunt statement of a Swabian rapeseed farmer from Böblingen who praises the seagulls of Peru as providing better manure even than his fellow countryman Hegel.

In an effort to impress the upper class around him and disguise his low-class origins, Jorrocks references guano in conversation at every chance he can.

"[70] Guano is also the namesake for one of the nucleobases in RNA and DNA: guanine, a purine base, consisting of a fused pyrimidine-imidazole planar ring system with conjugated double bonds.

Guanine was first obtained from guano by Julius Bodo Unger [de], who incorrectly first described it as xanthine, a closely related purine, in 1844.