The nest of the Peruvian booby is made of almost pure guano.
The Guanay cormorant has historically been the most important producer of guano.

Guano (from Spanish guano, from Quechua: wanu) is the accumulated excrement of seabirds and bats. As a manure, guano is a highly effective fertilizer due to its exceptionally high content of nitrogen, phosphate and potassium: nutrients essential for plant growth. Guano was also, to a lesser extent, sought for the production of gunpowder and other explosive materials. The 19th-century guano trade played a pivotal role in the development of modern input-intensive farming, but its demand began to decline after the discovery of the Haber-Bosch process of nitrogen fixing led to the production of synthetic fertilizers. The demand for guano spurred the human colonization of remote bird islands in many parts of the world. During the 20th century, guano-producing birds became an important target of conservation programs and influenced the development of environmental consciousness. Today, guano is increasingly sought after by organic farmers.[1]


Paul Szpak has co-authored several journal articles claiming that seabird guano consists of nitrogen-rich ammonium nitrate and urate, phosphates, as well as some earth salts and impurities, and that unleached guano from favored locales, such as the Chincha Islands off the coast of Peru, typically contains 8 to 16 percent nitrogen (the majority of which is uric acid), 8 to 12 percent equivalent phosphoric acid, and 2 to 3 percent equivalent potash.[2][3]

However, The Association of American Plant Food Control Officers (AAPFCO) defines Seabird guano as the hardened excrement from marine birds, which contains no organic matter or nitrogen and is a source of phosphates P2O5: "P- Hydroxylapatite - is a naturally-formed phosphate rock mineral with the formula Ca5(PO4)3(OH). The Fluorine content is less than 1%."[4]

Bat guano is fecal excrement from bats. Commercially harvested bat guano is used as an organic fertilizer.[5][6] All commercially sold bat guano is derived from insect-eating bats.[7] A study was done that demonstrated that, for fruit bats and insect bats, the composition of their guano was largely the same, and differed mainly based on their diet.[8]

Other Languages
Afrikaans: Ghwano
العربية: ذرق الطائر
Aymar aru: Mataxi
azərbaycanca: Quano
বাংলা: গুয়ানো
беларуская: Гуана
български: Гуано
català: Guano
čeština: Guáno
dansk: Guano
Deutsch: Guano
eesti: Guaano
Ελληνικά: Γκουανό
español: Guano
Esperanto: Guano
euskara: Guano
فارسی: کود مرغی
français: Guano
Gaeilge: Guanó
galego: Guano
한국어: 구아노
hrvatski: Guano
Ido: Guano
Bahasa Indonesia: Guano
italiano: Guano
עברית: גואנו
къарачай-малкъар: Гуано
Latina: Guanum
latviešu: Gvano
lietuvių: Guanas
magyar: Guanó
Bahasa Melayu: Guano
မြန်မာဘာသာ: ငှက်ချေးမြေဩဇာ
Nederlands: Guano
日本語: グアノ
Nordfriisk: Guano
norsk: Guano
norsk nynorsk: Guano
occitan: Güano
oʻzbekcha/ўзбекча: Guano
polski: Guano
português: Guano
română: Guano
Runa Simi: Wanay wanu
русиньскый: Гуано
русский: Гуано
Scots: Guanae
Simple English: Guano
slovenčina: Guáno
slovenščina: Gvano
српски / srpski: Гвано
srpskohrvatski / српскохрватски: Guano
Basa Sunda: Guano
suomi: Guano
svenska: Guano
Türkçe: Guano
українська: Гуано
Tiếng Việt: Phân chim
中文: 海鸟粪