Mike Read / Rock ptarmigan (Lagopus mutus) droppings, Cairngorms National Park, Highland Region, Scotland, UK, May.

Ashley Cooper / Adelie penguins (Pygoscelis adeliae) with tourists walking past the colony, Madder Cliffs, Joinville Island, Antarctica.

Ashley Cooper / Guano in an Adelie Penguin (Pygoscelis adeliae) colony at Madder Cliffs, Joinville Island, Antarctica.

Nick Upton / Sanderling (Calidris alba) feeding on Grey seal (Halichoerus grypus) droppings near a seal breeding colony, Norfolk, England, UK, January.

Ingo Arndt / Car parked under Common starling (Sturnus vulgaris) roost covered with droppings, Rome, Italy. January 2009

Markus Varesvuo / Willow grouse / Ptarmigan (Lagopus lagopus) snow cave and droppings, Utsjoki, Finland, February.

Markus Varesvuo / Capercaillie (Tetrao urogallus) droppings on snow, Kuusamo, Finland, April.

Markus Varesvuo / Rock Ptarmigan (Lagopus muta) droppings in half snow cave, Utsjoki, Finland, April.

Markus Varesvuo / Capercaillie (Tetrao urogallus) droppings on forest floor, Vaala, Finland, May.

Markus Varesvuo / Grey partridge (Perdix perdix) droppings on wet grass, Kauhajoki, Finland, October.

Markus Varesvuo / Capercaillie (Tetrao urogallus) droppings on forest floor, Vaala, Finland, May.

Markus Varesvuo / Willow grouse / Ptarmigan (Lagopus lagopus) droppings on snow, Inari Kiilopaa, Finland, April.

Markus Varesvuo / Hazel grouse (Tetrastes / Bonasa bonasia) droppings amongst pine needles and lichen on snow, Kuusamo, Finland, April.

Markus Varesvuo / Rock Ptarmigan (Lagopus muta) droppings left in its snow cave, Utsjoki, Finland, April.

Markus Varesvuo / Hazel grouse (Tetrastes / Bonasa bonasia) droppings, Vaala, Finland, May.

Jussi Murtosaari / Oystercatcher (Haematopus ostralegus) excreting, southern Finland, April.

Michele Westmorland / Blue-footed Boobies (Sula nebouxii) Galapagos Islands.

Claudio Contreras / Californian sea lions (Zalophus californianus) in front of guano covered rocks with Magnificent Frigatebirds (Fregata magnificens). Espiritu Santo Island National Park, Sea of Cortez (Gulf of Californ...

Claudio Contreras / Californian sea lions (Zalophus californianus) in front of guano covered rocks with Magnificent Frigatebirds (Fregata magnificens). Espiritu Santo Island National Park, Sea of Cortez (Gulf of Californ...

Claudio Contreras / Californian sea lions (Zalophus californianus) in front of guano covered rocks with Magnificent Frigatebirds (Fregata magnificens). Espiritu Santo Island National Park, Sea of Cortez (Gulf of Californ...

Tui De Roy / Blue-footed Boobies (Sula nebouxii) on guano covered rocks. Santa Cruz Island, Galapagos, June.

Tui De Roy / Blue-footed Boobies (Sula nebouxii) on guano covered rocks. Santa Cruz Island, Galapagos, June.

Kevin Schafer / Trees sprouting from cassowary droppings, Mission Beach, Queensland, Australia

Wild Wonders of Europe / Novák / Forest floor covered in Brambling (Fringilla montifringilla) droppings, Lödersdorf, Austria, February 2009

David Kjaer / Chough (Pyrrhocorax pyrrhocorax) feeding on sheep droppings, Pembrokeshire, Wales, UK

David Kjaer / Chough (Pyrrhocorax pyrrhocorax) feeding on sheep droppings, Pembrokeshire, Wales, UK

David Kjaer / Choughs (Pyrrhocorax pyrrhocorax) feeding on sheep droppings, Pembrokeshire, Wales, UK

Roger Powell / Lush growth of Common Scurvy-grass {Cochlearia officinalis} as a result of bird droppings below breeding cliff, Honoya island, Varanger, Norway

Nick Upton / Fiat 500 car covered in droppings after parking beneath huge Common starling roost (Sturnus vulgaris) central Rome, Italy, 1997

Dave Watts / Australian Cassowary {Casuarius casuarius}droppings containing seeds from tropical rainforest, Queensland, Australia

Niall Benvie / Black grouse {Tetrao tetrix} droppings and feather. Scotland, UK.

Michael & Patricia Fogden / Double-banded Courser (Rhinoptilus africanus) shading its egg which is camouflaged among antelope droppings, Etosha National Park, Namibia

Colin Varndell / Robin flying from nest with faecal sac {Erithacus rubecula} UK. By removing the droppings of their chicks and other toxic substances, robin parents keep the nest disinfected.

Niall Benvie / Red grouse droppings {Lagopus lagopus scoticus} Beinn Eighe NNR, Scotland, UK

WILLIAM OSBORN / Mistle thrush droppings with Mistletoe seeds in Apple tree. Gloucestshire, UK {Turdus

Kevin Schafer / Southern Cassowary (Casuarius casuarius) droppings, Atherton Tableland, Queensland, Australia

Michael & Patricia Fogden / Double-banded Courser (Rhinoptilus africanus) shading its egg which is camouflaged among antelope droppings, Etosha National Park, Namibia

Niall Benvie / Capercaille droppings {Tetrao urogallus} Abernethy, Scotland, UK

David Kjaer / Rock Ptarmigan droppings {Lagopus mutus} Highlands Scotland, UK

Ashley Cooper / Red grouse (Lagopus lagopus scotica) droppings on moorland, Yorkshire Dales, UK. March.

Nick Upton / Common starling (Sturnus vulgaris) emerging from its nest site under stone roof tiles on an old cottage with a beakful of droppings from its chicks to keep the nest clean, Lacock, Wiltshire, UK, May.