Tui De Roy / Red-footed booby (Sula sula), pair nest building in tree. Darwin Bay, Genovesa Island, Galapagos.

Alex Mustard / Galapagos green turtle (Chelonia mydas agassizii) swims over a coral reef. Darwin Island, Galapagos National Park, Galapagos Islands. East Pacific Ocean.

Nick Garbutt / Darwin's hawkmoth (Xanthopan morgani praedicta) showing extraordinarily long coiled tongue. Andasibe-Mantadia National Park, Madagascar.

Ole Jorgen Liodden / Woodpecker finch (Camarhynchus pallidus) using stick as a tool for foraging, Galapagos. Endemic.

Bert Willaert,Bert Willaert / Portrait of a Darwin's Frog (Rhinoderma darwinii) Chile, Vulnerable species

Paul D Stewart / 1881 portrait of Charles Robert Darwin (12 February 1809 - 19 April 1882) English Naturalist and author of the Origin of Species. 1922 Hand coloured portrait aquatint of Darwin by G. Sidney Hunt after...

Paul D Stewart / Male peacock (Pavo cristatus) displaying his ocellated tail feathers.

Paul D Stewart / Illustration of 'The Entomologist'. Rare copper print with original hand colouring, drawn by George Spratt, printed by George Madely, and sold individually as part of a series through Charles Tilt's F...

Paul D Stewart / A rare British broadsheet illustration with contemporary hand colouring, drawn and engraved by John Emslie and published by James Reynolds in 1849. It shows reconstructions of extinct creatures in the...

Pete Oxford / Galapagos Giant Tortoise (Geochelone elephantophus / Chelonoidis nigra) head portrait, Charles Darwin Research Station. Puerto Ayora,Santa Cruz Island, Galapagos, endemic

Pete Oxford / Small Ground Finch (Geospiza fuliginosa) being ringed for Avian pox research, Puerto Ayora, Santa Cruz Island, Galapagos, endemic

Pete Oxford / Finch specimens at the Charles Darwin Research Station, Puerto Ayora, Santa Cruz Island, Galapagos Islands, L to R Top: Large Ground Finch (Geospiza magnirostris), Woodpecker Finch (Cactospiza pallidu...

Pete Oxford / Finch specimens (Emberizidae) at the Charles Darwin Research Station, Puerto Ayora, Santa Cruz Island, Galapagos Islands

Kevin Schafer / Darwin's Fox (Pseudalopex fulvipes) portrait, in temperate rainforest, Chiloe Island, Chile, November, Critically Endangered

Kevin Schafer / Darwin's fox (Pseudalopex fulvipes) wild, Chiloe Island, Chile, Critically endangered species, November

Floris van Breugel / A rock collector explores piles of fluorescent minerals found in the tailings of the Pacific Tungsten Mine near Darwin, California. The bright colours are caused by fluorescence excited by a shortwave...

Tim Laman / Galapagos giant tortoise (Geochelone nigra / Geochelone elephantopus) feeding (captive). Charles Darwin Research Station, Santa Cruz Island, Galapagos Islands.

Kevin Schafer / Darwin's Zorro (Lycalopex fulvipes) a critically endangered fox, Chiloe Island, Chile

Warwick Sloss / Mudcrab {Scylla serrata} amongst mangroves at low tide, Darwin, NT, Australia

Warwick Sloss / Mudcrab {Scylla serrata} amongst mangroves at low tide, Darwin, NT, Australia

Warwick Sloss / Mudcrab {Scylla serrata} amongst mangroves at low tide, Darwin, NT, Australia

Mark Moffett / Large Ground Finch (Geospiza magnirostris) endemic species, extra large bill for cracking large seeds, largest of Darwin's 13 Finches, Santiago Island, Galapagos Islands, Ecuador

Tui De Roy / Pinta Island Galapagos Tortoise (Chelonoidis nigra abingdoni), Lonesome George, the last survivor of his race, Darwin Reserve Station, Santa Cruz Island, Galapagos Islands, Ecuador

Pete Oxford / D - Galapagos Giant tortoise portrait - Dome form {Geochelone elephantopus} retreating into shell. Darwin Research Station. Santa Cruz Is. Galapagos Islands, Ecuador. South America

Pete Oxford / Giant tortoise {Geochelone elephantopus} Galapagos Islands, Ecuador Charles Darwin Research Stn

Nick Garbutt / Lesser rhea (Rhea pennata) male and chicks in grassland. Torres del Paine National Park, Patagonia, Chile. November.

Nick Garbutt / Darwin's rhea (Pterocnemia pennata) with tower peaks in background. Torres del Paine National Park, Patagonia, Chile. December.

Nick Garbutt / Darwin's rhea (Pterocnemia pennata), two with tower peaks in background. Torres del Paine National Park, Patagonia, Chile. December.

Steven David Miller / Tombstone for 200 Giant clams (Tridacna gigas) illegally harvested in and around Evans Shoal, Darwin. Northern Territory, Australia. 2017.

Steven David Miller / Spangled drongo (Dicrurus bracteatus) perched on branch. Territory Wildlife Park, Darwin, Northern Territory, Australia. Captive.

Steven David Miller / Red-collared lorikeet (Trichoglossus rubritorquis) head peering out of nest box.Territory Wildlife Park, Darwin, Northern Territory, Australia. Captive.

Heather Angel / Buff tailed bumblebee (Bombus terrestris) feeding on Darwin's barberry (Berberis darwinii). Surrey, England, UK. November.

Heather Angel / Common bee fly (Bombylius major) nectaring on Darwin's barberry (Berberis darwinii). Surrey, England, UK. April.

Heather Angel / Darwin's slipper flower (Calceolaria uniflora) in UV light. Stamens and fleshy lip that provides food reward for polliator Least seedsnipe (Thinocorus rumicivorus) fluorescing. Native to Tierra de...

Heather Angel / Darwin's slipper flower (Calceolaria uniflora) in visible light. Stamens and fleshy lip that provides food reward for polliator Least seedsnipe (Thinocorus rumicivorus) fluorescing. Native to Tier...

Nick Hawkins / Small ground-finch (Geospiza fuliginosa) singing whilst perched on branch. Isabela Island, Galapagos.

Nick Hawkins / Small ground-finch (Geospiza fuliginosa). Santa Cruz Island , Galapagos.

Nick Hawkins / Medium ground-finch (Geospiza fortis) perched in tree. Isabela Island, Galapagos.

Nick Hawkins / Small ground finch (Geospiza fuliginosa) feeding on ectoparasites found on Marine iguana (Amblyrhynchus cristatus). Isabela Island, Galapagos.

Nick Hawkins / Small ground finch (Geospiza fuliginosa) standing on Marine iguana (Amblyrhynchus cristatus) leg. Finches feed on ectoparasites on iguanas. Isabela Island, Galapagos.

Nick Hawkins / Small ground finch (Geospiza fuliginosa) feeding on ectoparasites on Marine iguana (Amblyrhynchus cristatus) leg. Isabela Island, Galapagos.

Nick Hawkins / Small ground finch (Geospiza fuliginosa) feeding on ectoparasites whilst standing on Marine iguana (Amblyrhynchus cristatus) leg. Isabela Island, Galapagos.

Nick Hawkins / Small ground finch (Geospiza fuliginosa) standing on Marine iguana (Amblyrhynchus cristatus) leg. The finches feed on ectoparasites on iguanas. Isabela Island, Galapagos.

Nick Hawkins / Common cactus finch (Geospiza scandens) perched on Prickly pear (Opuntia). San Cristobal Island, Galapagos.

Nick Hawkins / Common cactus finch (Geospiza scandens) perched on twigs. San Cristobal Island, Galapagos.

Tui De Roy / Nazca booby (Sula granti), pair standing side by side, looking at camera. Darwin Bay, Genovesa Island, Galapagos.

Tui De Roy / Nazca booby (Sula granti), pair billing. Darwin Bay, Genovesa Island, Galapagos.

Tui De Roy / Nazca booby (Sula granti), adult with featherless chick and egg, at nest. El Barranco, Darwin Bay, Genovesa Island, Galapagos.

Tui De Roy / Red-footed booby (Sula sula) standing on rock with nesting material in beak. Darwin Bay, Genovesa Island, Galapagos.

Tui De Roy / Red-footed booby (Sula sula) nesting in tree on volcanic rock. Darwin Bay, Genovesa Island, Galapagos. June 2014.

Tui De Roy / Red-footed booby (Sula sula) standing on volcanic rock with birds flying overhead. Darwin Bay, Genovesa Island, Galapagos.

Tui De Roy / Red-footed booby (Sula sula) with nesting material, perched in tree. Darwin Bay, Genovesa Island, Galapagos.

Alex Mustard / School of Pacific creolefish (Paranthias colonus) swimming over a colourful reef. Darwin Island, Galapagos National Park, Galapagos Islands. East Pacific Ocean.

Alex Mustard / Flag cabrilla (Epinephelus labriformis) looking out from its lair between colourful volcanic boulders. Darwin Island, Galapagos National Park, Galapagos Islands. East Pacific Ocean.

Alex Mustard / Scalloped hammerhead shark (Sphyrna lewini) male in front of a school of Pacific creolefish (Paranthias colonus). Darwin Island, Galapagos National Park, Galapagos Islands. East Pacific Ocean.

Alex Mustard / School of Bonito (Sarda orientalis) in open water. Darwin Island, Galapagos National Park, Galapagos Islands. East Pacific Ocean.

Alex Mustard / Bigeye trevally (Caranx sexfasciatus) swim in front of volcanic boulders. Darwin Island, Galapagos National Park, Galapagos Islands. East Pacific Ocean.

David Fleetham / Young boy taking photo of Galapagos giant tortoise (Geochelone elephantopus) at Charles Darwin Research Station in Puerto Ayora, Santa Cruz Island, Galapagos, Ecuador. Model released.

Mary McDonald / Darwin Lake, Tagus cove, overlook, Isabela Island, Galapagos Islands, Ecuador. Pacific Ocean

Will Watson / Down House, Charles Darwin's long-term residence and Darwin Museum, English Heritage, Downe, Greater London, England, UK, July.

Mary McDonald / Great frigatebird (Fregata minor) male, inflating red gular / throat pouch, Genovesa Island, Darwin Bay, Galapagos Islands. April.

Mary McDonald / Great frigatebird (Fregata minor) male, inflating red gular throat pouch to attract a female, Genovesa Island, Darwin Bay, Galapagos Islands. April.

Emanuele Biggi / Darwin's spider (Caerostris darwinii), large web across a river, Ranomafana National Park, Madagascar

Emanuele Biggi / Darwin's spider (Caerostris darwinii), large web across a river, Ranomafana National Park, Madagascar

Emanuele Biggi / Darwin's spider (Caerostris darwinii) on web, Ranomafana National Park, Madagascar

Emanuele Biggi / Darwin's spider (Caerostris darwinii) on web, Ranomafana National Park, Madagascar

Emanuele Biggi / Darwin's spider (Caerostris darwinii) web, Ranomafana National Park, Madagascar

Juergen Freund / Saltwater crocodile (Crocodylus porosus) jumping up to grab a piece of chicken hung over the water by Adelaide River cruise boat skipper, Adelaide River, Darwin, Northern Territories, Australia

Juergen Freund / Saltwater crocodile (Crocodylus porosus) jumping up to grab a piece of chicken hung over the water by Adelaide River cruise boat skipper, Adelaide River, Darwin, Northern Territories, Australia

Juergen Freund / Saltwater crocodile (Crocodylus porosus) jumping up to grab a piece of chicken hung over the water by Adelaide River cruise boat skipper, Adelaide River, Darwin, Northern Territories, Australia

Juergen Freund / Saltwater crocodile (Crocodylus porosus) jumping up to grab a piece of chicken hung over the water by Adelaide River cruise boat skipper, Adelaide River, Darwin, Northern Territories, Australia

Juergen Freund / Saltwater crocodile (Crocodylus porosus) jumping up to grab a piece of chicken hung over the water by Adelaide River cruise boat skipper, Adelaide River, Darwin, Northern Territories, Australia

Juergen Freund / Saltwater crocodile (Crocodylus porosus) statue, Adelaide River, Darwin, Northern Territories, Australia

Juergen Freund / Saltwater crocodile (Crocodylus porosus) swimming towards the Adelaide River boat cruise, Adelaide River, Darwin, Northern Territories, Australia

Juergen Freund / Saltwater crocodile (Crocodylus porosus) swimming towards the Adelaide River boat cruise, Adelaide River , Darwin, Northern Territories, Australia

Juergen Freund / Saltwater crocodile (Crocodylus porosus) jumping up to grab a piece of chicken hung over the water by Adelaide River cruise boat skipper, Adelaide River, Darwin, Northern Territories, Australia

Juergen Freund / Saltwater crocodile (Crocodylus porosus) jumping up to grab a piece of chicken hung over the water by Adelaide River cruise boat skipper, Adelaide River, Darwin, Northern Territories, Australia

Melvin Grey / Darwin Wallace poison frog (Epipedobates darwinwallacei) adult, Mindo, Ecuador. June

Mike Read / Dark-faced ground-tyrant (Muscisaxicola maclovianus maclovianus) perched on Gorse (Ulex Europaeus) Darwin, Falkland Islands, November.

Tui De Roy / Darwin's Finch (Geospiza sp) picking ticks from Volcan Alcedo Giant Tortoise (Chelonoidis nigra vandenburghi), Alcedo Volcano, Isabela Island, Galapagos Islands, Ecuador

Tui De Roy / Darwin's Finch (Geospiza sp) group picking ticks from Volcan Alcedo Giant Tortoise (Chelonoidis nigra vandenburghi), Alcedo Volcano, Isabela Island, Galapagos Islands, Ecuador

Tui De Roy / Darwin's Finch (Geospiza sp) picking off ticks from Volcan Alcedo Giant Tortoise (Chelonoidis nigra vandenburghi), Alcedo Volcano, Isabela Island, Galapagos Islands, Ecuador

Tui De Roy / Darwin's Finch (Geospiza sp) picking off ticks from Volcan Alcedo Giant Tortoise (Chelonoidis nigra vandenburghi), Alcedo Volcano, Isabela Island, Galapagos Islands, Ecuador

Tui De Roy / Volcan Alcedo Giant Tortoise (Chelonoidis nigra vandenburghi) and Darwin's Finch (Geospiza sp), Alcedo Volcano, Isabela Island, Galapagos Islands, Ecuador

Tui De Roy / Lava gull (Larus fuliginosus) on water, Darwin Bay, Genovesa Island, Galapagos

Tui De Roy / Lava gull (Larus fuliginosus) on beach, Darwin Bay, Genovesa Island, Galapagos

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) pair in courtship, Darwin Bay, Genovesa Island, Galapapgos

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) juvenile and adult in breeding plumage, Darwin Bay, Genovesa Island, Galapapgos

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) Darwin Bay, Genovesa Island, Galapagos

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) pair mating Darwin Bay, Genovesa Island, Galapagos

Tui De Roy / Swallow-tailed gull (Creagrus furcatus) pair mating Darwin Bay, Genovesa Island, Galapagos

Bernard Castelein / Lesser rhea (Pterocnemia pennata) Quetena, Altiplano, Bolivia

Bernard Castelein / Lesser rhea (Pterocnemia pennata) Quetena, Altiplano, Bolivia

Ernie Janes / Tulip 'Tequila Sunrise' (Tulipa Darwin Hybrid) growing in garden. England, UK.