Marie Read / American avocets (Recurvirostra americana) two during aggressive (territorial) encounter, Bear River Migratory Bird Refuge, Utah, USA, May.

Nigel Cattlin / Marsh crane fly (Tipula oleracea) larva / leatherjacket attacking cereal plant, Wheat (Triticum aestivum), at soil level.

Nick Upton / Large marsh horsefly (Tabanus autumnalis) resting on a fence, Dorset, UK, July.

Nick Upton / Large marsh horsefly (Tabanus autumnalis) resting on a fence, Dorset, UK, July.

Konrad Wothe / Slow motion clip of a Bumblebee (Bombus) nectaring on a Marsh gladiolus (Gladiolus palustris), with a Bee fly (Bombyliidae) flying nearby, Bavaria, Germany, July.

Rod Williams / Snail-killing fly (Tetanocera Sp) Sutcliffe Park Nature Reserve, Eltham, London, England, UK. August.

David Kjaer / Marsh Snipefly (Rhagio tringarius) Ham Wall RSPB Reserve, Somerset Levels

Lorraine Bennery / Caterpillar larva of Elephant hawkmoth (Deilephila elpenor) on Grass of parnassus (Parnassia palustris) with hoverfly visiting flower, Regional Vosges Balloons Regional Park, France, August.

Nick Upton / Hoverfly (Volucella bombylans var. bombylans) a mimic of the Red-tailed bumblebee nectaring on Common spotted orchid (Dactylorhiza fuchsii) on grassland meadow cleared of scrub to improve the habitat...

Rod Williams / Snail-eating fly (Trypetoptera punctulatus) Brockley Cemetery, Lewisham, London, UK. May

Nick Upton / Marsh fly / Snail-killing fly (Dichetophora obliterata) standing on a Bramble leaf, Wiltshire hedgerow, UK, September.

Jussi Murtosaari / Flies (Brachycera) on leaf, Parikkala, Etela-Karjala / South Karelia, Etela-Suomi / South Finland, Finland. June

Jussi Murtosaari / Fly (Brachycera) on Lily of the Valley berries, Parikkala, Etela-Karjala / South Karelia, Etela-Suomi / South Finland, Finland. September

Kim Taylor / Snail-killing fly (Coremacera marginata) pair mating. Surrey, England, September.

Kim Taylor / Snail-killing fly (Coremacera marginata) pair mating, viewed from above. Surrey, England, September.

Nick Upton / Common / Eurasian crane chick (Grus grus) aged two days, swallowing a Leatherjacket (Tipulidae) given to it by its mother, 'Chris' age four years, released by the Great Crane Project, as father 'Monty...

Jussi Murtosaari / Hen Harrier (Circus cyaneus) female on a nest with mosquitos, central Finland, June.

Nick Upton / A Marsh fly / Snail-killing fly (Dichetophora finlandica), nationally scarce in the UK, standing on a Woolly thistle leaf (Cirsium eriophorum), chalk grassland meadow, Wiltshire, UK, June.

Nick Upton / Marsh fly / Snail-killing fly (Limnia unguicornis) on Woolly thistle leaf (Cirsium eriophorum), chalk grassland meadow, Wiltshire, UK, July.

Nick Upton / Marsh fly / Snail Killing fly (Tetanocera sp.) standing on Reed grooming front legs. Wiltshire river bank, UK, May.

Nigel Cattlin / Marsh fly / snail-killing fly (Sepedon aenescens) adult on a paddy Rice (Oryza sativa) leaf, Philippines

Premaphotos / Marsh brown-edged tipula crane fly / Daddy longlegs (Tipula oleracea) leatherjacket larva, UK

Premaphotos / Common green colonel soldier fly (Oplodontha / Odontomyia viridula) in a marsh, UK

Premaphotos / Large fruit fly (Xyphosia miliaria) pair mating on Marsh thistle host plant, UK

Premaphotos / Red-eyed snail fly (Tetanocera arrogans) mating pair, UK

Premaphotos / Snail fly (Elgiva cucularia), mating pair, UK

TOM MANGELSEN / Whooping cranes {Grus americana} fly over freshwater marsh breeding grounds Wood Buffalo National Park, Alberta Canada

TOM MANGELSEN / Whooping cranes {Grus americana} fly over freshwater marsh breeding grounds Wood Buffalo National Park, Alberta Canada

TOM MANGELSEN / Whooping cranes {Grus americana} fly over freshwater marsh breeding grounds Wood Buffalo National Park, Alberta Canada

Guy Edwardes / European pond turtle/terrapin (Emys orbicularis) swimming in pond with head above water and a fly resting on its snout, near Bratsigovo, Bulgaria, May

Nick Upton / Little grebe (Tachybaptus ruficollis) swimming with Caddis fly (Trichoptera sp.) larvae in beak, marshland pool, Magor Marsh nature reserve, Gwent Levels, Wales, UK, March.

Roman Willi / Marsh flies (Tetanocera sp.) mating pair, Lucerne, Switzerland. May.

Doug Wechsler / Narrow-headed marsh fly (Helophilus fasciatus) nectaring on Aster (Aster sp.) flower, Pennsylvania, USA. October.

Bernard Castelein / Crane fly (Tipulidae sp.) resting on Marsh gentian (Gentiana pneumonanthe), Brasschaat, Belgium. October.

Andy Sands / Stripe-backed snailkiller fly (Limnia unguicornis), female, in typical head down pose on grass. Buckinghamshire, England, UK. May. Focus Stacked.

Andy Sands / Stripe-backed snailkiller fly (Limnia unguicornis), male, in typical head down pose, with rain drops on grass. Buckinghamshire, England, UK. May. Focus Stacked.

Andy Sands / Stripe-backed snailkiller fly (Limnia unguicornis), male, climbing back up grass after rainy shower. Buckinghamshire, England, UK. May. Focus Stacked.

Andy Sands / Snail-killing fly (Pherbellia cinerella) in typical head down pose on grass stem with rain drops. Buckinghamshire, England, UK. May. Focus Stacked.

Andy Sands / Blue long-horned snailkiller fly (Sepedon sphegea), male, in typical head down pose on sedge stem. Buckinghamshire, England, UK. May. Focus Stacked.

Andy Sands / Blue long-horned snailkiller fly (Sepedon sphegea), male, in typical head down pose on sedge stem. Buckinghamshire, England, UK. May. Focus Stacked.

Terry Whittaker / Marmalade hoverfly (Episyrphus balteatus) feeds on nectar from a Marsh marigold (Caltha palustris), Greater Manchester, September.

Terry Whittaker / Marmalade hoverfly (Episyrphus balteatus) feeds on nectar from a Marsh marigold (Caltha palustris), Greater Manchester, September.

Nick Upton / Common butterwort (Pinguicula vulgaris) leaf with a small fly trapped by the sticky droplets this carnivorous plant exudes from glandular hairs, Cwm Cadlan National Nature Reserve, Brecon Beacons, Wal...

Gerrit Vyn / Black tern (Chlidonias niger) hunting over water in prairie wetland for emerging midges (Chironomidae) Medicine Lake National Wildlife Refuge, Montana, USA. June.

Doug Wechsler / Marsh fly (Sciomyzidae sp.) on log, La Selva Biological Station, Costa Rica.

Doug Wechsler / Marsh fly (Limnia sp.) on leaf, Philadelphia, Pennsylvania, USA. June.

John Chan / Brown pelican (Pelecanus occidentalis) preening as shorebirds fly by at a tidal basin, Bolsa Chica Ecological Reserve, Southern California, USA, November.

Nick Upton / Marsh snipefly (Rhagio tringarius) resting on a leaf, Wiltshire hedgerow, UK, May.

Neil Aldridge / Camera moving around a Common spotted orchid (Dactylorhiza fuchsii) while it is visited by a hoverfly (Syrphidae sp.) in woodland, North Somerset, United Kingdom, June.

John Waters / Marsh Marigold (Caltha palustris) with Drone fly (Eristalis tenax) active in background, Bristol, UK, March.

John Waters / Drone fly (Eristalis tenax) on flower of Marsh Marigold (Caltha palustris), Bristol, UK, March.

John Waters / Drone fly (Eristalis tenax) on flower of Marsh Marigold (Caltha palustris), Bristol, UK, March.

Nigel Cattlin / Insectivorous leaves and sticky leaf hairs of a Sundew (Drosera aliciae)

John Chan / Juvenile female Hen harrier (Circus cyaneus) regurgitating a pellet as shorebirds fly by in foreground, Bolsa Chica Ecological Reserve, Southern California, USA, November.

Andy Sands / Snail Killing Fly (Sciomyzidae sp.) perched on reed stem above pond, Hertfordshire, England, UK, August

Andy Sands / Snail killing fly (Sciomyzidae sp.) perched on reed stem above pond, East Sussex, England, UK, July. Focus Stacked