Alex Hyde / Cave Pearls, formed as dripping water rich in calcium salts deposits calcite around a small nucleus (often a sand grain). The constant movement of each cave pearl by the dripping water keeps them roun...

Alex Hyde / Cave Pearls, formed as dripping water rich in calcium salts deposits calcite around a small nucleus (often a sand grain). The constant movement of each cave pearl by the dripping water keeps them roun...

Alex Hyde / Cave Pearls, formed as dripping water rich in calcium salts deposits calcite around a small nucleus (often a sand grain). The constant movement of each cave pearl by the dripping water keeps them roun...

Paul Hobson / King Eider (Somateria spectabilis) with water splashing off its beak after surfacing from a dive, Varanger, Norway, March.

Paul Hobson / Steller's Eider (Polysticta stelleri) diving underwater, Varanger, Norway, March.

Fergus Gill / Dipper (Cinclus cinclus) by splashing river, Perthshire, Scotland. May.

Fergus Gill / Dipper (Cinclus cinclus) silhouetted against splashing waters of river with insect prey, Perthshire, Scotland. May 2013

Philippe Clement / Common starling (Sturnus vulgaris) bathing in bird bath in garden, Belgium, April.

Chris & Monique Fallows / Storm blowing waves and spray over pier at Kalk Bay harbour at dawn, False Bay, Cape Town, South Africa.

Staffan Widstrand / Little egret (Egretta garzetta) taking off, Pulicat Lake, Tamil Nadu, India, January 2013.

Florian Möllers / Common Goldeneye (Bucephala clangula) captive, male bathing, splashing water, May, Vogelpark Marlow, Germany. May

Claudio Contreras / Yellow legged gull (Larus livens) bathing, Santispac beach, Bahia Concepcion, Sea of Cortez (Gulf of California), Mexico, May