Denis-Huot / Crowned crane (Balearica regulorum gibbericeps) head portrait, Masai-Mara game reserve, Kenya.

Denis-Huot / Three Yellow baboons (Papio cynocephalus) female, sitting on a log mutual grooming, one female holding her infant, Amboseli National Park, Kenya.

Daniel Nunez / Yellow-blotched palm-pit viper (Bothriechis aurifer) resting on branch in cloudforest at night, Ranchitos del Quetzal Reserve, Baja Verapaz, Guatemala.

Andy Sands / Slime mould (Stemonitis sp.) newly emerged bright yellow sporangia on rotting log, Buckinghamshire, England, UK. September. Focus stacked.

Alex Mustard / Schools of fish, including Bohar snappers (Lutjanus bohar), Yellow-spotted trevally (Carangoides orthogrammus) and Bigeye trevally (Caranx sexfasciatus) gathering adjacent to a colourful coral reef wi...

Alex Mustard / Pygmy lemon gobies (Lubricogobius exiguus) pair, guarding their home in a glass bottle, Batangas marine protected area, Luzon, Philippines, Verde Island Passages, Pacific Ocean.

Alex Mustard / Saddleback anemonefish (Amphiprion polymnus) and a Spotted porcelain crab (Neopetrolisthes maculatus) living together in an anemone. Bitung, North Sulawesi, Indonesia, Lembeh Strait, Molucca Sea.

Bernard Castelein / Blue tit (Parus caeruleus) perched on branch, Brasschaat, Belgium. January.

Bernard Castelein / Blue tit (Parus caeruleus) standing at edge of pool, Brasschaat, Belgium. January.

Bernard Castelein / Raft spider (Dolomedes fimbriatus) resting on Tansy flowers (Tanacetum vulgare), Klein Schietveld, Brasschaat, Belgium. August.

Joel Sartore / Photo Ark / Sulphur crested cockatoo (Cacatua sulphurea occidentalis) raising its crest and looking around, Prigen Conservation Breeding Ark, Java, indonesia. Critically endangered. Controlled conditions.

Emanuele Biggi / Close-up of Balearic green toad (Bufotes balearicus) male's eye, Rome, Italy.