Robert Thompson / Garden tiger moth (Arctia caja) Killard Point NNR, Strangford, County Down, Northern Ireland, UK, July.

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) colony huddling, males incubating eggs, on sea ice under full moon in polar night. Atka Bay, Antarctica. July 2017.

Staffan Widstrand / Kittiwakes (Rissa tridactyla) nesting on wall of house, Vardo town, Varanger Peninsula, Norway, March.

Terry Whittaker / 2020VISION / Feral pigeon (Columba livia) on ground, with people's feet in the background, South Bank, London, England, UK, September. Did you know? In the 16th Century England pigeon guano was the only source of...

Wild Wonders of Europe / Geslin / Kestrel (Falco tinninculus) perched in roosting hole in stone building in the Vatican garden, Rome, Italy, March 2010

JIM CLARE / Guano unloading gantry with Peruvian boobies (Sula variegata). Chincha Island, Peru, South America

Morley Read / Timelapse of a King swallowtail (Papilio thoas) butterfly caterpillar drinking water from the surface of a leaf, ), showing bird dropping camouflage, Napo Province, Ecuadorian Amazon. (non-ex)

Morley Read / King swallowtail (Papilio thoas) butterfly caterpillar, showing bird dropping camouflage, Napo Province, Ecuadorian Amazon. (non-ex)

JIM CLARE / Nests of Guanay cormorants, (Phalacrocorax bougainvilliiorum) after breeding has finished, shows build-up of guano around the nest. The colonies are strictly protected and the guano will be harvested...

JIM CLARE / Nest of Guanay cormorants, (Phalacrocorax bougainvilliiorum), after breeding has finished, shows build-up of guano around the nest. The colonies are strictly protected and the guano will be harvested...

JIM CLARE / Balls formed in and around nests of guanay cormorants (Phalacrocorax bougainvilliiorum) as they walk over moist ground and coat loose stones, or even eggs, with guano. Each of the balls usually has a...

JIM CLARE / Balls formed in and around nests of guanay cormorants (Phalacrocorax bougainvilliiorum) as they walk over moist ground and coat loose stones, or even eggs, with guano. Each of the balls usually has a...

JIM CLARE / Nests of Guanay cormorants, (Phalacrocorax bougainvilliiorum), after breeding has finished, shows build-up of guano around the nest. The colonies are strictly protected and the guano will be harvested...