Marie Read / Ruby-throated Hummingbird (Archilocus colubris), male flying in to feed from cardinal flowers (Lobelia cardinalis) New York, USA. August.

Marie Read / American avocet (Recurvirostra americana), adult in breeding plumage foraging by sweeping its bill from side to side through shallow water, Orange County, California, USA, April.

Marie Read / California quail (Callipepla californica), male emerging from behind snowbank in winter, Mono Lake Basin, California, USA

Marie Read / Canada geese (Branta canadensis) two during territorial fight in early spring, Ithaca. New York, USA

Marie Read / Black-necked stilts (Himantopus mexicanus) pair performing post-copulatory display (as copulation ends, the male slides off the female leaving his wings draped over her and crossing his bill with hers...

Marie Read / Blue jay (Cyanocitta cristata) holding an acorn in its bill whilst perched on tree stump, with autumn foliage, New York, USA, October.

Marie Read / Black skimmers (Rynchops niger), three in non-breeding plumage on beach, Fort De Soto Park, St. Petersburg, Florida, USA. January. Digitally altered to remove distractions.

Marie Read / Great blue heron (Ardea herodias) in breeding plumage, head and shoulders showing plumes on crown and neck, Montezuma National Wildlife Refuge, New York, USA, May.

Marie Read / American oystercatcher (Haematopus palliatus) adult feeding chick, Long Island, New York, USA. June.

Nick Upton / White stork (Ciconia ciconia) pair performing an up-down display with bill clattering on their nest in an Oak tree, Knepp estate, Sussex, UK, April 2019. This is the first recorded instance of White s...

Guy Edwardes / Saddle-billed stork (Ephippiorhynchus senegalensis), Moremi Game Reserve, Botswana.

Guy Edwardes / Portland Bill Lighthouse, Isle of Portland, Dorset, England, UK. November 2015.

Guy Edwardes / Portland Bill Lighthouse, Isle of Portland, Dorset, England, UK. November 2011.

Guy Edwardes / Portland Bill Lighthouse at night, Isle of Portland, Dorset, England, UK. September 2016.

Guy Edwardes / Portland Bill Lighthouse at sunset, Isle of Portland, Dorset, England, UK. November 2009.

Ingo Arndt / Brown Booby (Sula leucogaster plotus) head portrait, with wide bill open, Christmas Island, Indian Ocean, Australian Territory, November

Danny Green / Atlantic Puffins (Fratercula arctica) bill rubbing, Skomer Island, Wales, UK, April

Danny Green / Atlantic Puffin (Fratercula arctica) pair bill rubbing part of courtship ritual, Skomer Island, Wales, UK, May

Andres M. Dominguez / Dove's-foot crane's-bill leaf (Geranium molle) and algae in ice with air bubbles, Sierra de Grazalema Natural Park, southern Spain, February.

Markus Varesvuo / Puffins (Fratercula arctica) 'bill-knocking' in a display of courtship behaviour, Norway, Scandinavia, April.

Michael Pitts / Diver Ron Howse ascending the shot line in Lyme Bay, off Portland Bill, Dorset, England, UK, September 2010. Model released.

D. Parer & E. Parer-Cook / Platypus (Ornithorhynchus anatinus) grinding prey between plates of its bill, Atherton Tableland, Queensland, Australia

David Tipling / Huli Wigmen from the Tari Valley in Southern Highlands of Papua New Guinea, wearing a bill from Blyth's Hornbill as decoration, August 2011

Bence Mate / Close up of Grey Heron (Ardea cinerea) with bighead carp (Hypophthalmichthys nobilis) in bill, Lake Csaj, Kiskunsagi National Park, Hungary

Bence Mate / Close up of Dalmatian pelican (Pelecanus crispus) eye and bill, Danube Delta, Romania

Bence Mate / Tip of bill and feathers of Dalmatian pelican (Pelecanus crispus) Danube Delta, Romania

Bence Mate / Head portrait of Dalmatian pelican (Pelecanus crispus) with pouched bill wide open. Danube Delta, Romania

Bence Mate / Close up of Dalmatian pelican (Pelecanus crispus) eye and bill, Danube Delta, Romania

Bence Mate / Head portrait of Dalmatian pelican (Pelecanus crispus) with pouched bill wide open. Danube Delta, Romania

Bertie Gregory / 2020VISION / White spoonbill (Platalea leucorodia) feeding with water dripping from its bill, Brownsea Island, Dorset, England, UK, January

Bertie Gregory / 2020VISION / Avocet (Recurvirostra avosetta) silhouetted as its feeds at sunrise, Brownsea Island, Dorset, winter.

Andy Sands / Kingfisher (Alcedo atthis) male preening wing with muddy bill, Hertfordshire, England, UK, March.

Laurie Campbell / Golden eagle (Aquila chrysaetos) chick, one week, in eyrie showing egg-tooth on tip of bill, Argyll, Scotland, early May

Andy Sands / Spotted Flycatcher (Muscicapa striata) perched with ringlet butterfly in bill. West Sussex, England, July. Highly commended, 'Animal Portraits' category, British Wildlife Photography Awards (BWPA) com...

David Tipling / 2020VISION / Black-tailed godwit (Limosa limosa) taking off from tidal pool, Snettisham RSPB reserve, Norfolk, UK, March. 2020VISION Exhibition. 2020VISION Book Plate. Did you know? The black-tailed godwit's bill...

Bence Mate / Dalmatian pelican (Pelecanus crispus) low angle perspective of open bill, Lake Kerkini, Greece, February. Winner, Eric Hosking award, 2011 Wildlife Photographer of the Year competition

Pete Oxford / Sword-billed Hummingbird (Ensifera ensifera), the only species of bird to have a bill longer than the rest of its body, approaching a flower. Yanacocha Reserve, Ecuador.

Pete Oxford / Silhouette of a Sword-billed Hummingbird (Ensifera ensifera), the only species of bird to have a bill longer than the rest of its body. Yanacocha Reserve cloud forest, Ecuador.

Brent Stephenson / Campbell Albatross (Thalassarche impavida) swimming on the water with bill wide open in threat display. Note the diagnostic pale eye of this species. Off North Cape, New Zealand, April.

Orsolya Haarberg / Wood crane's-bill (Geranium sylvaticum) flowers, Telemark, Norway

Andy Sands / Meadow Crane's-bill (Geranium pratense) Close up of flower and seedpods, Bedfordshire, England, UK, June

Gerrit Vyn / Ruddy Duck (Oxyura jamaicensis) male in breeding plumage performing a "bubbling display"which is used in both courtship and aggressive territorial encounters. The male holds its head and tail and 2 ro...

Guy Edwardes / Flowering Fleabane (Erigeron glaucus) with Portland Bill Lighthouse in the distance, Isle of Portland, Dorset, England, June 2006

Wild Wonders of Europe / Radisics / Clammy crane's bill, (Pelargonium glutinosum) flowers, Madeira, March 2009

Pete Oxford / Measuring bill size of Waved albatross (Phoebastria irrorata) Punta Suarez, Española / Hood Island, Galapagos Islands

Doug Perrine / Atlantic sailfish {Istiophorus albicans} hits sardine with bill while feeding on bait ball of Spanish sardines / gilt sardine / pilchard / round sardinella {Sardinella aurita} off Yucatan Peninsula, M...

Peter Lewis / Waves crashing over the rocks at Portland Bill with lighthouse in the background, Dorset, UK

Kim Taylor / Green hermit {Phaethornis guy} approaching flower with curved corolla matching the bird's bill, Trinidad, West Indies, Digital composite.

Anup Shah / Lesser Flamingo {Phoeniconaias minor} bill-fencing as part of courtship, Lake Nakuru, Kenya.

Tom Vezo / Least tern {Sternula antillarum} standing in water with a fish in bill, USA.

Kim Taylor / Euopean kingfisher {Alcedo atthis} taking off with a stickleback fish in bill, UK.

David Noton / Sunset at Portland Bill, Dorset, UK

Mark Moffett / Large Ground Finch (Geospiza magnirostris) endemic species, extra large bill for cracking large seeds, largest of Darwin's 13 Finches, Santiago Island, Galapagos Islands, Ecuador

Norbert Wu / Toco Toucan (Ramphastos toco) bill is actually light and spongy, Brazil

Norbert Wu / Toco Toucan (Ramphastos toco) bill is actually light and spongy, Brazil

Norbert Wu / Swordfish (Xiphias gladius) worldwide, can tolerate temperatures of five degrees Celsius and dive to 650 meters, uses sword to kill prey such as squid, can grow to 14 feet and 1200 pounds, Sardinia, I...

Norbert Wu / American Paddlefish (Polyodon spathula) can sense electrical fields with long paddle, native to Mississippi River drainage system

Dave Watts / Pair of Satin bowerbirds {Ptilonorhynchus violaceus} at bower East Australia. Female in bower, male displaying to her using blue ornaments. Satin Bowerbirds collect blue and yellow ornaments and the m...

John Downer / African hawk eagle head portrait {Hieraaetus spilogaster}. Zimbabwe, Africa.

John Downer / Golden eagle head portrait {Aquila chrysaetos} powerful hook bill, Switzerland

Doug Gimesy / Platypus researchers taking bill measurements from a Platypus (Ornithorhynchus anatinus).Warburton, Victoria, Australia. October, 2018. Model released.

Doug Gimesy / Platypus researcher holding a platypus (Ornithorhynchus anatinus) whilst field assistant measures the bill length. It was captured as part of a Melbourne Water study to monitor the local population. C...

Doug Gimesy / Platypus researchers holding a Platypus (Ornithorhynchus anatinus) and measuring bill length. It was captured as part of a Melbourne Water study to monitor the local population. Chum Creek, Healsville...

Doug Gimesy / Platypus researchers taking bill measurements from a Platypus (Ornithorhynchus anatinus) Healsville, Victoria, Australia. September, 2018. Model released.

Doug Gimesy / Blood is drawn from the bill of an anaesthetised Platypus (Ornithorhynchus anatinus) Snowy River, Dalgety, NSW, Australia. September 2017 Model release supplied.

Doug Gimesy / Platypus researchers taking bill measurements from a Platypus (Ornithorhynchus anatinus). Healsville, Victoria, Australia. September, 2018. Model released.

Doug Gimesy / Closed eye and top of bill of a platypus (Ornithorhynchus anatinus) Photographed under controlled conditions - platypus anaesthetised in-field as part of research. Darmouth, Victoria, Australia. May 2...

Doug Gimesy / Top view of the bill of a platypus (Ornithorhynchus anatinus). Photographed under controlled conditions - platypus anaesthetised as part of research project. Darmouth, Victoria, Australia. Background...

Doug Gimesy / Closed eye and top of bill of a Platypus (Ornithorhynchus anatinus). Darmouth, Victoria, Australia. May.

Doug Gimesy / Top view of the bill of a platypus (Ornithorhynchus anatinus). Darmouth, Victoria, Australia. May 2018. Controlled conditions.

Doug Gimesy / Platypus researchers taking bill measurements Platypus (Ornithorhynchus anatinus). Warburton, Victoria, Australia. October, 2018. Model released.

Doug Gimesy / Blood is drawn from the bill of an anaesthetised platypus (Ornithorhynchus anatinus) it will be put into a test tube for later analysis. Snowy River, Dalgety, NSW, Australia. September 2017. Model re...

Doug Gimesy / Platypus researcher holding a platypus (Ornithorhynchus anatinus) whilst field assistant measured bill length. It was captured as part of a Melbourne Water study to monitor the local population. Chum...

Doug Gimesy / Platypus researchers holding a platypus (Ornithorhynchus anatinus) whilst field assistant measures the bill length. It was captured as part of a Melbourne Water study to monitor the local population....

Doug Gimesy / Platypus researchers measuring the bill length of a Platypus (Ornithorhynchus anatinus) which was captured as part of a Melbourne Water study to monitor the local population. Chum Creek, Healsville, V...

Doug Gimesy / Platypus (Ornithorhynchus anatinus) bill, close up. Controlled conditions, platypus anaesthetised as part of Platypus Conservation Initiative, University of New South Wales research project. Darmouth,...

Doug Gimesy / Researchers from Earthcare St Kilda preparing to microchip a moulting Little penguin (Eudyptula minor). Bill diameter will be measured to determine sex. St Kilda breakwater, Melbourne, Victoria, Austr...

Ralph Pace / Swordfish (Xiphias gladius) with tags to determine effectiveness of fishing gear, San Diego, California

Ralph Pace / Swordfish (Xiphias gladius) with tags to determine effectiveness of fishing gear, San Diego, California

John Shaw / Ringed kingfisher (Megaceryle torquata) male positioning small fish in bill. Pantanal, Brazil. September.

John Shaw / Ruddy duck (Oxyura jamaicensis) in a small marsh pond, doing courtship display where it beats its breast with bill to create bubbles. British Columbia, Canada. June.

Marie Read / Golden-fronted woodpecker (Melanerpes aurifrons), male, Cozad Ranch, Rio Grande Valley, Texas, USA, March.

Marie Read / Tricolored heron (Egretta tricolor) adult in breeding plumage capturing fish by half-running half-flying across water's surface and stabbing with its bill, Viera Wetlands, Brevard County, Florida,...

Marie Read / Tufted puffin (Fratercula cirrhata), adult in breeding plumage flying in preparing to land, St. Paul, Pribilof Islands, Alaska, USA, July.

Marie Read / White-winged Crossbill (Loxia leucoptera), male feeding on Douglas-fir cones, Ithaca, New York, USA, January.

Marie Read / Yellow-bellied Sapsucker (Sphyrapicus varius), male drumming, long exposure, New York, USA, April.

Marie Read / Roseate spoonbill (Ajaia ajaja), adult in breeding plumage flying in to land on a perch, Orlando, Florida, USA, March.

Marie Read / California Gull (Larus californicus), foraging for alkali flies (Ephydra hians) by running through swarm snapping its bill, on the shore at Mono Lake, California, USA. Digital frame expansion.

Marie Read / Black-necked Stilt (Himantopus mexicanus), foraging in water, with reflection, Bear River Migratory Bird Refuge, Utah, USA, May.

Marie Read / Northern gannets (Morus bassanus) performing sky-pointing display with outspread wings as part of courtship, Cape St. Mary's Ecological Reserve, Newfoundland, Canada. June.

Marie Read / Pileated woodpecker (Dryocopus pileatus) male excavating in search of food, New York, USA. Digital composite.

Marie Read / Pileated Woodpecker (Dryocopus pileatus) male, at feeding excavation in tree trunk in winter, Freeville, New York, USA, January.

Marie Read / Red-breasted Mergansers (Mergus serrator) male in foreground performing courtship display to female in background (left), Aurora, New York, USA, April.

Marie Read / Roseate spoonbill (Ajaia ajaja) adult in breeding plumage in flight over water, mangroves in background,Tampa Bay, Florida, USA, March.

Marie Read / American oystercatcher (Haematopus palliatus), closeup of individual feeding by using its chisel-shaped bill to pry open shellfish, Fort De Soto Park, St. Petersburg, Florida, USA, March.

Ernie Janes / Wood crane's-bill (Geranium sylvaticum) 'Cyrils Fancy' in flower. England, UK, May.