Jeff Vanuga / Close up of eye of a bull African Elephant (Loxodonta africana) showing 'tears', Masai Mara Game Reserve, Kenya, September

Nigel Cattlin / Dwarf daffodil (Narcissus triandrus 'Hawera'). Cultivated in garden. Berkshire, England, April

Eric Baccega / Keepers from Beauval Zoo weeping tears of joy following the reintroduction of two female Western lowland gorillas (Gorilla gorilla gorilla). Gorilla Protection Project, Gabon. 2019.

Eric Baccega / Keepers from Beauval Zoo weeping tears of joy following the reintroduction of two female Western lowland gorillas (Gorilla gorilla gorilla). Gorilla Protection Project, Gabon. 2019.

Pete Oxford / Yellow-spotted Amazon River Turtle (Podocnemis unifilis) sunbathing surrounded by butterflies sipping salts from the turtle's tears, Yasuni National Park, Amazon, Ecuador

Martin Gabriel / Angel's Tears Daffodil (Narcissus triandrus) in flower. Monfrague National Park, Extremadura, Spain, March.

Konrad Wothe / Marmalade Hover Fly (Episyrphus balteatus) approaching Maiden's Tears (Silene vulgaris) flowers, Upper Bavaria, Germany

Adrian Davies / Dry stone wall with Mind-your-own-business / Baby? Tears {Soleirolia / Helxine soleirolii} Mulranney, County Mayo, Republic of Ireland - invasive plant from Corsica and Sardinia

Doug Perrine / Australian flatback sea turtle (Natator depressus) nesting female with excretions from salt glands leaking out of eyes like tears, Crab Island, Torres Strait, Queensland, Australia

Pete Oxford / Wall of Tears built by prisoners in early 1900's, Isabela Is, Galapagos

Paul D Stewart / Early Lithographic print by Honegger drawn by Fuchs, from Dr. Shinz, 'Naturgeschichte und Abbilldungen des Menschen der verschiedenen' 1827/1840, with hand colouring. A trio of Papua New Guinea men wi...

Rick Tomlinson / "Merit Cup" tears her main at the finish of the Whitbread Race leg to Auckland, 1997.

Rick Tomlinson / Blowout during the Admiral's Cup for "Corum Rubis" on the Solent as her mainsail tears and the spinnaker loses control, 1993.

Paul Harcourt Davies / Angel's tears (Narcissus triandrus) in flower, Orvieto, Umbria, Italy. March.

Joel Sartore / Photo Ark / Southern sea otter (Enhydra lutris nereis) aged 19 tears, head portrait, Aquarium of the Pacific, California. Endangered. Captive.

Nigel Cattlin / Mind our own business plant (Soleirolia soleirolii) leaves and flowers, Devon, England, UK. September