Pascal Kobeh / Short-finned pilot whale (Globicephala macrorhynchus) close to the surface, Costa Rica. Pacific ocean.

Melvin Grey / Short-billed dowitcher (Limnodromus griseus) adult, breeding plumage, Churchill, Manitoba, Canada, May.

Melvin Grey / Short-billed dowitcher (Limnodromus griseus) adult, Churchill, Manitoba, Canada

Melvin Grey / Short-billed dowitcher (Limnodromus griseus) adult, Churchill, Manitoba, Canada, May.

Andy Rouse / Short Eared Owl (Asio flammeus) taking off, blurred motion photograph, UK, January. Captive

Luis Quinta / Common dolphins (Delphinus delphis) pair in mating ritual, Atlantic ocean, Portugal, July.

Roland Seitre / Gray Short-tailed Opossum (Monodelphis domestica) babies suckling, Moscow Zoo, Russia. Captive

Niall Benvie / Red-winged Grasshopper (Oedipoda germanica) against white background. France, July.

Loic Poidevin / Short billed dowitcher (Limnodromus griseus) and Grey plover (Pluvialis squatarola) on beach at Pointe Pelee, Ontario, Canada, May

Petra Wegner / Woman feeding carrot to a Guinea Pig (Cavia porcellus) grey short coated, on garden lawn,

Petra Wegner / Guinea Pig (Cavia porcellus) grey short coated, on garden lawn, being fed carrot

Freya Short / Argentine / South American grey fox (Pseudalopex / Lycalopex griseus) cubs resting, Torres del Paine National Park, Chile

Freya Short / South American grey fox (Pseudolopex / Lycalopex griseus) standing in snow, Torres del Paine National Park, Chile, July

Freya Short / Argentine / South American Grey fox (Pseudolopex / Lycalopex griseus) sleeping, Torres del Paine National Park, Chile

Freya Short / Argentine / South American grey fox (Pseudalopex / Lycalopex griseus) cub standing on a wood pile, Torres del Paine National Park, Chile

Freya Short / Argentine / South American grey fox {Pseudolopex griseus} Torres del Paine National Park, Chile

Freya Short / Argentine / South American grey fox (Pseudalopex / Lycalopex griseus) cubs resting, Torres del Paine National Park, Chile

Freya Short / Argentine / South American grey fox (Pseudalopex / Lycalopex griseus) cubs resting, Torres del Paine National Park, Chile

Solvin Zankl / Larval instar of the German grasshopper (Oedipoda germanica)

Rod Williams / Grey short tailed opossum {Monodelphis domestica} captive, from Brazil

Nigel Cattlin / Marsh cudweed (Gnaphalium uliginosum) grey wooly plant flowering on a dry pathway on chalk downland, Berkshire, July

Nigel Cattlin / Cow parsley (Anthriscus sylvestris) section through hollow ridged smooth-haired stem, June, Berkshire

Nigel Cattlin / Cow parsley (Anthriscus sylvestris) section through hollow ridged smooth-haired stem, June, Berkshire

Nigel Cattlin / Autumn lady's tresses (Spiranthes spiralis), a small orchid with white flowers on Greenham Common, Berkshire, September

Nigel Cattlin / Autumn lady's tresses (Spiranthes spiralis), a small orchid with white flowers on Greenham Common, Berkshire, September

Nature Production / Two Grasshoppers {Eusphingonotus japonicus} mimicking stones, Japan

Nicolas Rakotopare / Eastern grey kangaroo (Macropus giganteus) mother with joey in her pouch. The mother scratches herself and then hops foward to feed in short grass. Queensland, Australia. January.

Nicolas Rakotopare / Eastern grey kangaroo (Macropus giganteus) mother and joey feeding in short grass. While the female is feeding, the joey is hoping around the frame. Queensland, Australia. January.

Grant Maslowski / Fairy prion (Pachyptila turtur) with chick, nestled in artificial nesting box, St Clair, Dunedin, South Island, New Zealand.

Grant Maslowski / Fairy prion (Pachyptila turtur) chick, resting at night, St Clair, Dunedin, South Island, New Zealand. Controlled conditions.

Grant Maslowski / Fairy prion (Pachyptila turtur) chick, resting at night, St Clair, Dunedin, South Island, New Zealand. Controlled conditions.

Nick Upton / Short-finned pilot whales (Globicephala macrorhynchus) surfacing near Dolphin and Whale watching trip, Tenerife, Canary Islands, Atlantic Ocean, October.

Joel Sartore / Photo Ark / Gray short-tailed opossum (Monodelphis domestica) with tongue poking out, portrait, Houston Zoo. Captive.

Joel Sartore / Photo Ark / Gray short-tailed opossum (Monodelphis domestica) portrait, Houston Zoo. Captive.

Oscar Dewhurst / Grey squirrel (Sciurus carolinensis) stood upright on short grass. London, England, UK. March.