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

Denis-Huot / Lesser flamingo (Phoeniconaias minor) flock on Lake Magadi under a stormy sky, Rift Valley, Kenya.

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 / Two Red Sea goatfish (Parupeneus forsskali) wrapping their barbels around each other, fighting, Sharm El Shiekh, Sinai, Egypt. Red 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.

Joel Sartore / Photo Ark / African pompano (Alectis ciliaris) juvenile swimming, Blue Corner, Shizuoka. Captive.

Joel Sartore / Photo Ark / Javan blue flycatcher (Cyornis banyumas) male looking around, Prigen Conservation Breeding Ark, Java, Indonesia. Critically endangered. Controlled conditions.

Joel Sartore / Photo Ark / Swallow tanager (Tersina viridis) male looking around before flying out of the frame, Walsrode Bird Park. Captive.

Joel Sartore / Photo Ark / Eurasian blue tit (Cyanistes caeruleus) juveniles calling, Cheshire Animals, Churton, UK. Controlled conditions.

Franco Banfi / Pacific sardine (Sardinops sagax) bait ball trying to evade California sea lions (Zalophus californianus), Pacific coast, Baja California, Mexico.

Franco Banfi / Mahi-mahi (Coryphaena hippurus) school hunting Pacific sardine (Sardinops sagax) bait ball. Two Mahi-mahi propel themselves towards the shoal, catching two fish. California sea lions (Zalophus califor...