Doug Perrine / Bryde's whale {Balaenoptera brydei / edeni} with throat pleats expanded after feeding on baitball of Sardines {Sardinops sagax} off Baja California, Mexico, Eastern Pacific Ocean. Veolia Environnement...

Robert Valentic / Eastern tiger snake (Notechis scutatus) female, Yarra River corridor in suburban Melbourne, Victoria, Australia, in mid-summer. She is in a defensive pre-strike position with hood expanded, accompanie...

Doug Perrine / Bryde's whale (Balaenoptera brydei / edeni) with throat pleats expanded after engulfing part of a school of Sardines, off Baja California, Mexico (Eastern Pacific Ocean)

Tim MacMillan / John Downer Pr / Kuhl's gecko flying - every edge of body expanded into membrane that acts as a wing as it glides (Resolution restriction - image digitised from film, 'Weird Nature' tv series)

Edwin Giesbers / Spiny flower mantis (Pseudocreobotra wahlbergii) with wings expanded, captive, occurs in Africa.

Tui De Roy / Brown pelicans (Pelecanus occidentalis) feeding underwater, with throat pouch expanded, Galapagos

Kim Taylor / Brimstone butterfly (Gonepteryx rhamni) with wings almost fully expanded after after emerging from pupa, Surrey, England, July. Sequence 8 of 8.

Wim van den Heever / Zebra (Equus quagga) leaping during stampede, Serengeti, Tanzania. Vignette added and right edge expanded.

Tui De Roy / Brown pelicans (Pelecanus occidentalis) feeding underwater, with throat pouch expanded, Galapagos

Daniel Heuclin / Egyptian cobra (Naja haje) with head raised up and hood expanded, near Taroudant, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head raised up and hood expanded, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head raised up and hood expanded, near Ouarzazate, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head raised up and hood expanded, near Ouarzazare, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head raised up and hood expanded, near Ouarzazare, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head raised up and hood expanded, near Ouarzazare, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head raised up and hood expanded, near Ouarzazare, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head up and hood expanded, near Tiznit, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head up and hood expanded, near Taroudant, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head up and hood expanded, near Taroudant, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head up and hood expanded, near Taroudant, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head up and hood expanded, town in the background, near Taroudant, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head up and hood expanded, near Taroudant, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head up and hood expanded, near Taroudant, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head up and hood expanded, near Taroudant, Morocco.

Daniel Heuclin / Asian spitting cobra (Naja siamensis) with head raised and hood expanded, South East Asia.

Daniel Heuclin / Asian spitting cobra (Naja siamensis) with head raised and hood expanded, South East Asia.

Daniel Heuclin / Asian spitting cobra (Naja siamensis) with head raised and hood expanded, South East Asia.

Daniel Heuclin / Asian spitting cobra (Naja siamensis) with head raised and hood expanded, South East Asia.

Daniel Heuclin / Asian spitting cobra (Naja siamensis) with head raised and hood expanded, South East Asia.

Daniel Heuclin / Asian spitting cobra (Naja siamensis) with head raised and hood expanded, South East Asia.

Daniel Heuclin / Asian spitting cobra (Naja siamensis) with head raised and hood expanded, South East Asia.

Daniel Heuclin / Asian spitting cobra (Naja siamensis) with head raised and hood expanded, South East Asia.

Daniel Heuclin / Asian spitting cobra (Naja siamensis) with head raised and hood expanded, South East Asia.

Daniel Heuclin / Asian spitting cobra (Naja siamensis) with head raised and hood expanded, South East Asia.

Daniel Heuclin / Asian spitting cobra (Naja siamensis) with head raised and hood expanded, South East Asia.

Daniel Heuclin / Asian spitting cobra (Naja siamensis) with head raised and hood expanded, South East Asia.

Daniel Heuclin / Egyptian cobra (Naja haje) with head raised, hood expanded and fangs on display, on near Taroudant, Morocco.

Daniel Heuclin / Egyptian cobra (Naja haje) with head raised and hood expanded, near Ouarzazate, Morocco.

Tony Phelps / Cape Cobra (Naja nivea) aggressive with hood expanded with curious Yellow mongooses (Cynictis penicillata) deHoop Nature Reserve, Western Cape, South Africa, December.

Tony Phelps / Cape Cobra (Naja nivea) aggressive with hood expanded with curious Yellow mongooses (Cynictis penicillata) deHoop Nature Reserve, Western Cape, South Africa, December.

Tony Phelps / Cape cobra (Naja nivea) with hood expanded, and Yellow mngoose (Cynictis penicillata) deHoop Nature Reserve, Western Cape, South Africa, December.

Mark Carwardine / Humpback whale (Megaptera novaeangliae) lunge feeding at surface showing expanded throat grooves, Princess Royal Island, Great Bear Rainforest, British Columbia, western Canada

Rod Williams / Golden poison dart frog (Phyllobates terribilis) with throat pouch / vocal sacs expanded. Captive occurs Colombia. Endangered species

Doug Perrine / Bryde's whale (Balaenoptera brydei / edeni) with throat pleats expanded after feeding on baitball of Sardines (Clupeidae) Off Baja California, Mexico, Eastern Pacific Ocean, November

Doug Perrine / Bryde's whale (Balaenoptera brydei / edeni) with throat pleats expanded after feeding on baitball of Sardines (Clupeidae) with California sea lion (Tetreapturus audax) in background. Off Baja Californ...

Robert Thompson / Hairy dragonfly (Brachytron pratense) adult newly emerged from pupal case, before wings have expanded, Montiaghs Moss NNR, County Antrim, Northern Ireland, UK, sequence 4/5

Doug Perrine / Bryde's whale (Balaenoptera brydei / edeni) with throat pleats expanded after feeding on baitball of Sardines (Sardinops sagax) off Baja California, Mexico (Eastern Pacific Ocean )

Doug Perrine / Bryde's whale (Balaenoptera brydei / edeni) with throat pleats expanded after feeding on baitball of Sardines (Sardinops sagax) off Baja California, Mexico (Eastern Pacific Ocean )

SINCLAIR STAMMERS / Fossil of a Trilobite (Clymenella / Eohomalonotus sp) from the Ordovician period, Uppermost Llanvirn Series, Rehamna, Morocco. The expanded axial segments and shovel nose snout indicate a burrowing mo...

DOC WHITE / Blue whale (Balaenoptera musculus) feeding at surface, throat pouch expanded, Pacific

David Shale / Deepsea Female Anglerfish {Melanocoetus} with stomach expanded and forced forward into mouth on ascent from depth.

Kim Taylor / Meadow horsetail {Equisetum pratense} spores expanded, UK.

Kim Taylor / Meadow horsetail {Equisetum pratense} cone with expanded spores. UK.

Michael & Patricia Fogden / Banded King Shoemaker (Prepona demophon) catterpillar anterior body expanded to expose false eye spots and mimic snake, note eggs of parasitic Tachinid fly, rainforest, Costa Rica

Paul D Stewart / Copper engraving of dinosaur femur, from Robert Plot's 1677 'Natural History of Oxfordshire'. Dug out of a quarry in 'the Parish of Cornwell' in Oxfordshire on the land of (and donated by) Sir Thomas...

DOC WHITE / Blue whale (Balaennoptera musculus) feeding, throat pouch expanded, Monterey, California, USA

Andy Sands / RF - Azure damselfly (Coenagrion puella) newly emerged imago with wings half expanded, East Sussex, England, UK. May. Focus stacked. (This image may be licensed either as rights managed or royalty fre...

David Fleetham / Spotted porcupinefish (Diodon hystrix), inflated with seawater, a defensive behaviour, Hawaii, Pacific Ocean.

Alex Mustard / Detail of the expanded polyps of Bubble coral (Plerogyra sp.) on a reef. Baa Atoll, Maldives. Indian Ocean

Andy Sands / Slime mould (Arcyria obvelata ), a tight group with sporangia fully expanded. Hertfordshire, England, UK. September. Focus stacked image.

Andy Sands / Slime mould (Hemitrichia clavata) sporangia, sponge like structure containing spores has expanded to five times its original size, spores dispersed by wind. Hertfordshire, England, UK. August. Focus s...

John Chan / California least terns (Sternula antillarum browni) engage in food exchange during courtship, Bolsa Chica Ecological Reserve, California, USA July. Digitally expanded canvas.