Bert Willaert / Composite image of American fish species introduced to Europe: Pumpkinseed sunfish (Lepomis gibbosus, left), Brown bullhead (Ameiurus nebulosus, right) and Eastern mudminnow (Umbra pygmaea, under), ph...

Jean E. Roche / Aerial view of vineyards and fruit trees edged with Italian poplar trees, introduced to the Camargue during the 19th century and planted for protection against the wind, near Arles, Camargue, Southern...

Fergus Gill / 2020VISION / Grey Squirrel (Sciurus carolinensis) in urban park in winter. Glasgow, Scotland, December. Did you know? Scientists believe that some of the UK's native Red Squirrels are gaining immunity to the pox i...

Fergus Gill / 2020VISION / Mute Swan (Cygnus olor) taking off from flock on water. Scotland, December. Did you know? Richard the Lionheart is said to have introduced Mute Swans to Britain

Rob Jordan / 2020VISION / Signal crayfish (Pacifastacus leniusculus) in a defensive posture after being caught by The Tweed Foundation monitoring the species population and spread on the River Till, Northumberland, England, UK...

Rob Jordan / 2020VISION / Signal crayfish (Pacifastacus leniusculus) in a defensive posture after being caught by The Tweed Foundation monitoring the species population and spread on the River Till, Northumberland, England, UK...

Ross Hoddinott / 2020VISION / Sika deer (Cervus nippon), stag, hind and young, amongst flowering heather, Arne RSPB reserve, Dorset, England, UK, August. Did you know? This East Asian deer's name 'Sika' is the Japanese word for 'd...

Terry Whittaker / 2020VISION / Konik horse (Equus caballus) two stallions fighting, Wicken Fen, Cambridgeshire, UK, June

Terry Whittaker / 2020VISION / Konik horse (Equus caballus) two stallions fighting, Wicken Fen, Cambridgeshire, UK, June

Terry Whittaker / 2020VISION / Konik horse (Equus caballus) herd grazing with two stallions interacting, Wicken Fen, Cambridgeshire, UK, June 2011

Terry Whittaker / 2020VISION / Konik horse (Equus caballus) stallion and juvenile on Wicken Fen, Cambridgeshire, UK, June 2011

Ross Hoddinott / 2020VISION / European Beech tree {Fagus sylvatica} Yellow leaves in autumn, Sence Valley Forest Park, Leicestershire, UK. November. 2020VISION Book Plate. Did you know? Although thought to have been introduced by...

Andrew Walmsley / Eurasian Coot (Fulica atra) on water, Christchurch, New Zealand, February

Michel Roggo / Signal crayfish (Pacifastacus leniusculus) Europe, introduced from North America

Jerry Monkman / Nature Conservancy employees cutting back Japanese knotweed (Fallopia japonica) in an invasive species eradication effort on the TNC's Silverweed Seep preserve in Plainfield, New Hampshire, USA.

Michael Durham / Red Imported Fire Ant (Solenopsis invicta), also known as RIFA, worker portrait, highly invasive introduced species, Texas

Laurie Campbell / Juvenile European beaver {Castor fiber} striping bark off a Birch trunk at the Aigas Field Studies Centre, European Beaver demonstration project, Inverness-shire, Scotland, August 2008

Andy Rouse / Wild boar (Sus scrofa) sow with five piglets, Kent, UK

Andy Rouse / Wild boar (Sus scrofa) in woodland, Kent, UK

Piotr Naskrecki / European Spotted Amber Ladybird (Hippodamia variegata) was accidentaly introduced to South Africa in 1967, this species feeds mostly on aphids, South Africa

Suzi Eszterhas / African Lion (Panthera leo) five week old cub playing with adult male after being introduced to pride for the first time, vulnerable, Masai Mara National Reserve, Kenya

Suzi Eszterhas / African Lion (Panthera leo) five week old cub approaches adult male after being introduced to pride members for the first time, vulnerable, Masai Mara National Reserve, Kenya

Michael Durham / Rainbow Trout (Oncorhynchus mykiss) pair underwater in Utah, a popular game fish native to coastal streams of the western US and introduced into the eastern US and worldwide

Pete Cairns / European Lynx (Lynx lynx) adult female peering out from behind tree in winter, birch forest. Bardu, Norway, captive

Pete Cairns / European Lynx (Lynx lynx) adult male stalking through winter birch forest, Bardu, Norway, captive

Steven David Miller / Cuban tree frog (Osteopilus septentrionalis) native of West Indies introduced into Florida, USA

Michael Durham / Brown Rat (Rattus norvegicus) raiding urban garbage, common pest species native to Europe, introduced worldwide

Konrad Wothe / Dandelion (Taraxacum officinale) ready to release its seeds, Germany, introduced into North America as a salad green now is invasive weed

Mark Moffett / Argentine Ant (Linepithema humile) group feed on soft nutritious eliasome at the tip of a fynbos shrub and discard the seeds without burying them, jeopardizing the fynbos community, South Africa

Katherine Feng / Giant Panda (Ailuropoda melanoleuca) Gongzhu is successfully re-introduced to one of her nine week old twin cubs which she initially rejected, China Conservation and Research Center for the Giant Pand...

Yva Momatiuk & John Eastcott / California Condor (Gymnogyps californianus) immature bird flying with transmitter attached, critically endangered extinct in wild and recently re-introduced, 9-10 foot wingspan, Marble Canyon, Arizona

Mitsuaki Iwago / European Rabbit (Oryctolagus cuniculus) group along Dingo fence, once introduced for hunting now are considered a pest, Australia

Fred Bavendam / West Indian Manatee (Trichechus manatus) eating Hydrilla (Hydrilla sp) an introduced plant that often clogs waterways, Blue Spring State Park, Florida

Doug Wechsler / Giant toad {Bufo marinus} introduced species to Puerto Rico, Caribbean

John Cancalosi / Fallow deer buck during rutting season, England, UK. Species introduced to UK by Romans

Martin H Smith / Hedgehog (Erinaceus europaeus) eating Oystercatcher eggs on South Uist, Scotland. Introduced to the island in 1974, the hedgehog population has increased dramatically and is causing populations of nes...

Nick Upton / Turkish sage (Phlomis russeliana) close up of flowers, a garden escape, flowering on verge of country lane through a chalk grassland meadow, Wiltshire, UK, June.

Nick Upton / American mink (Mustela vison) swimming in a drainage channel, RSPB Greylake, Somerset Levels, UK, May.

Nick Upton / American mink (Mustela vison) swimming in a drainage channel, RSPB Greylake, Somerset Levels, UK, May.

Sue Daly / Diving instructor hunting lionfish (Pterois volitans), an invasive species which has been released in the Atlantic, Bonaire, Dutch Antilles, Caribbean, February 2012, Model Released

Sue Daly / Diving instructor hunting lionfish (Pterois volitans), an invasive species which has been released in the Atlantic, Bonaire, Dutch Antilles, Caribbean, February 2012, Model Released

Sue Daly / Diving instructor hunting lionfish (Pterois volitans), an invasive species which has been released in the Atlantic, Bonaire, Dutch Antilles, Caribbean, February 2012, Model Released

Sue Daly / Diving instructor hunting lionfish (Pterois volitans), an invasive species which has been released in the Atlantic , Bonaire, Dutch Antilles, Caribbean, February 2012, Model Released

Sue Daly / Diving instructor hunting lionfish (Pterois volitans), an invasive species which has been released in the Atlantic, Bonaire, Dutch Antilles, Caribbean, February 2012, Model Released

Sue Daly / Diving instructor hunting lionfish (Pterois volitans), an invasive species which has been released in the Atlantic, Bonaire, Dutch Antilles, Caribbean, February 2012, Model Released

Sue Daly / Diving instructor hunting lionfish (Pterois volitans), an invasive species which has been released in the Atlantic, Bonaire, Dutch Antilles, Caribbean, February 2012, Model Released

Sue Daly / Diving instructor hunting lionfish (Pterois volitans), an invasive species which has been released in the Atlantic Bonaire, Dutch Antilles, Caribbean, February 2012, Model Released

Sue Daly / Diving instructor spearing lionfish (Pterois volitans), an invasive species which has been released in the Atlantic Bonaire, Dutch Antilles, Caribbean, February 2012, Model Released

Sue Daly / Diving instructor hunting lionfish (Pterois volitans), an invasive species which has been released in the Atlantic Bonaire, Dutch Antilles, Caribbean, February 2012, Model Released

Sue Daly / Diving instructor hunting lionfish (Pterois volitans), an invasive species which has been released in the Atlantic, Bonaire, Dutch Antilles, Caribbean, February 2012, Model Released

Sue Daly / Lionfish in the kitchen of Cactus Blue restaurant, Kralendijk, Bonaire, Caribbean

Sue Daly / Red Lionfish (Pterois volitans) juvenile, an invasive species in the West Atlantic, Bonaire, Dutch Antilles, Caribbean

Sue Daly / Red Lionfish (Pterois volitans) juvenile, an invasive species in the West Atlantic, Bonaire, Dutch Antilles, Caribbean

Sue Daly / Red Lionfish (Pterois volitans) an invasive species in the West Atlantic, Bonaire, Dutch Antilles, Caribbean

Sue Daly / Lionfish fritters served at Cactus Blue restaurant, Kralendijk, Bonaire

Sue Daly / Sign outside Cactus Blue restaurant saying 'We (kill) serve and cook lionfsh!' Lionfish is an invasive species in this region. Kralendijk, Bonaire, Caribbean

Sue Daly / Red Lionfish (Pterois volitans) juvenile, an invasive species in the West Atlantic, Bonaire, Dutch Antilles, Caribbean

Sue Daly / Red Lionfish (Pterois volitans) juvenile, an invasive species in the West Atlantic, Bonaire, Dutch Antilles, Caribbean

Wild Wonders of Europe / Muñoz / Retuerta horses (Equus ferus caballus) herd walking away, once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horses (Equus ferus caballus) herd grazing, once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horses (Equus ferus caballus) herd drinking at pond, once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, S...

Wild Wonders of Europe / Muñoz / Retuerta horses (Equus ferus caballus) herd drinking at pond, once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, S...

Wild Wonders of Europe / Muñoz / Retuerta horses (Equus ferus caballus) once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horse (Equus ferus caballus) walking profile, once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horses (Equus ferus caballus) once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horse (Equus ferus caballus) running, once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horses (Equus ferus caballus) herd running, once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horses (Equus ferus caballus) once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Domestic cattle (Bos taurus) once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Domestic cattle (Bos taurus) once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horses (Equus ferus caballus) once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horses (Equus ferus caballus) once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horse (Equus ferus caballus) once native, now re-introduced to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horse (Equus ferus caballus) once native, herd released to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horse (Equus ferus caballus), released to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Wild Wonders of Europe / Muñoz / Retuerta horse (Equus ferus caballus) herd released to graze in Campanarios de Azaba Biological Reserve, a rewilding Europe Area, Salamanca, Castilla y Leon, Spain

Sue Flood / Arctic fox (Vulpes lagopus) in summer coat, Yankicha Island in the Kuril Island chain, Russian Far East. Arctic Foxes were introduced to Yankicha by Japanese fur traders who wanted to start a breeding...

Alex Hyde / Signal Crayfish (Pacifastacus leniusculus), a species introduced to the UK from North America. They are far larger and more aggressive than the native species, and can easily out-compete them. Photog...

Kevin Schafer / African Tulip Tree (Spathodea campanulata) flowers, Santa Cruz Island, Galapagos Islands, Ecuador

Mark Carwardine / Predator fence near Te Anua, South Island, New Zealand, designed to keep introduced predators out of designated zones to protect flightless birds, January 2009

Colin Varndell / Wild rhododendron shrub in flower. Studland, Dorset, UK, May

Tui De Roy / Mourning gecko (Lepidodactylus lugubris), introduced species, prevalent inside buildings, Galapagos islands, Academy Bay, Santa Cruz Island, Galapagos

Colin Varndell / Marsh frog (Rana ridibunda) at rest, Bexington, Dorset, England, UK, May

David Woodfall / Large blue butterfly (Phengaris arion), a re-introduced species from Scandinavian stock, Green Down Somerset Wildlife Trust Reserve, England, UK, July 2012

David Woodfall / Large blue butterfly (Phengaris arion), a re-introduced species from Scandinavian stock, Green Down Somerset Wildlife Trust Reserve, England, UK, July 2012

David Woodfall / Large blue butterfly (Phengaris arion), a re-introduced species from Scandinavian stock, Green Down Somerset Wildlife Trust Reserve, England, UK, July 2012

David Woodfall / Large blue butterfly (Phengaris arion), a re-introduced species from Scandinavian stock, Green Down Somerset Wildlife Trust Reserve, England, UK, July 2012

David Woodfall / Large blue butterfly (Phengaris arion), a re-introduced species from Scandinavian stock, Green Down Somerset Wildlife Trust Reserve, England, UK, July 2012

David Woodfall / Large blue butterfly (Phengaris arion), a re-introduced species from Scandinavian stock, Green Down Somerset Wildlife Trust Reserve, England, UK, July 2012

David Woodfall / Large blue butterfly (Phengaris arion), a re-introduced species from Scandinavian stock, Green Down Somerset Wildlife Trust Reserve, England, UK, July 2012

David Woodfall / Large blue butterfly (Phengaris arion), a re-introduced species from Scandinavian stock, Green Down Somerset Wildlife Trust Reserve, England, UK, July 2012

Stephen Belcher / Yellow Crazy Ant (Anoplolepis gracilipes) guarding Scale Insects (Tachardina aurantiaca), Christmas Island National Park, Christmas Island, Australia

Stephen Belcher / Yellow Crazy Ant (Anoplolepis gracilipes) guarding Scale Insects (Tachardina aurantiaca), Christmas Island National Park, Christmas Island, Australia

Stephen Belcher / Christmas Island Red Crab (Gecarcoidea natalis) and Blue Crab (Discoplax hirtipes) carcasses, death caused by Yellow Crazy Ants (Anoplolepis gracilipes), Christmas Island National Park, Christmas Isla...

Stephen Belcher / Christmas Island Red Crab (Gecarcoidea natalis) and Blue Crab (Discoplax hirtipes) carcasses, death caused by Yellow Crazy Ants (Anoplolepis gracilipes), Christmas Island National Park, Christmas Isla...

Stephen Belcher / Yellow Crazy Ant (Anoplolepis gracilipes) group killing Christmas Island Red Crab (Gecarcoidea natalis), Christmas Island National Park, Christmas Island, Australia